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Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Class 11 MCQ


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90 Questions MCQ Test - Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology

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Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 1

Which of the following is the smallest cell-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 1

PPLO( pleuro pneumonia like organisms ) comes under the kingdom monerans . They lack cell wall and have size of 0.1 micrometre. That's why they are smallest.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 2

Which of the following statements is not true-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 2

Animal cells do not have chloroplasts. Chloroplasts work to convert light energy of the Sun into sugars that can be used by cells. The entire process is called photosynthesis and it all depends on the little green chlorophyll molecules in each chloroplast. Plants are the basis of all life on Earth.

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Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 3

All cells are derived from pre-existing cells"
is the famous generalization of-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 3
Introduction:
The famous generalization "All cells are derived from pre-existing cells" is attributed to a scientist named Rudolf Virchow. This principle is known as the cell theory and is a fundamental concept in biology.
Rudolf Virchow and the Cell Theory:
- Rudolf Virchow was a German physician and pathologist who lived in the 19th century.
- He is considered one of the founders of modern pathology and is known for his significant contributions to medical science.
- In 1855, Virchow proposed the cell theory, which states that all living organisms are composed of cells and that cells only arise from pre-existing cells.
- This principle contradicted the prevailing belief at the time, which suggested that cells could arise spontaneously.
Supporting Evidence:
- Virchow's cell theory was supported by his observations and experiments.
- He studied cellular pathology and found that diseases were caused by abnormalities in cells.
- Virchow also examined cell division and observed that new cells formed through the replication of pre-existing cells.
- His work provided strong evidence for the idea that cells can only arise from pre-existing cells.
Significance of the Cell Theory:
- The cell theory revolutionized our understanding of biology and laid the foundation for modern cell biology.
- It provided a unifying concept that explained the organization and functioning of living organisms.
- The cell theory also contributed to advancements in medical science, as it highlighted the importance of studying cells in understanding diseases.
Conclusion:
Rudolf Virchow's generalization that "All cells are derived from pre-existing cells" has become a fundamental principle in biology. His observations and experiments led to the development of the cell theory, which revolutionized our understanding of living organisms.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 4

Which of the following is true of the carbohydrate portion of the cell membrane-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 4
The carbohydrate portion of the cell membrane:
- Contributes to the polycationic charge on the extracellular surface: This statement is false. The carbohydrate portion of the cell membrane does not contribute to the polycationic charge on the extracellular surface. The charge on the cell membrane is primarily determined by the presence of membrane proteins and lipids.
- Is 1% of the plasma membrane: This statement is true. The carbohydrate portion of the cell membrane makes up approximately 1% of the total plasma membrane. The majority of the plasma membrane is composed of lipids (around 50%) and proteins (around 50%).
- Is found primarily in the form of free saccharide groups: This statement is false. The carbohydrate portion of the cell membrane is not primarily found in the form of free saccharide groups. Instead, it is usually attached to lipids or proteins, forming glycolipids or glycoproteins.
- Has a symmetric distribution: This statement is false. The distribution of carbohydrates on the cell membrane is asymmetric. The carbohydrate chains are often longer on the extracellular side of the membrane and shorter on the cytoplasmic side.
Therefore, the correct answer is B: It is 1% of the plasma membrane.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 5

Plasmalemma of animal cells is elastic due to the presence of-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 5

Plasma membrane is a lipid bilayer in which the proteins, cholesterol and carbohydrates are incorporated which give it a mosaic-like appearance. The lipid bilayer renders the flexibility to the cell membrane. 

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 6

Causes of Cancer is -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 6

Mitosis is closely controlled by the genes inside every cell. Sometimes, this control can go wrong. If that happens in just a single cell, it can replicate itself to make new cells that are also out of control. These are cancer cells. They continue to replicate rapidly without the control systems that normal cells have. Cancer cells will form lumps, or tumours, that damage the surrounding tissues. Sometimes, cancer cells break off from the original tumour and spread in the blood to other parts of the body. When a tumour spreads to another part of the body it is said to have metastasized. They continue to replicate and make more tumours. These are called secondary tumours. Medicines that are used to treat cancer are sometimes aimed at killing cells that are rapidly dividing by mitosis. They inhibit the synthesis or function of DNA - this type of treatment is called chemotherapy. More modern medicines target specific cancers in different ways. Many inhibit the growth signals for that type of cell.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 7

The most abundant substance of middle lamella is-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 7

Middle lamella connects cell walls of  two adjacent cells. Pectic compounds are mainly present in the middle lamella.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 8

Cell wall is the secretory product of-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 8

The cell wall is derived from minute vesicles produced in the Golgi apparatus present in the cytoplasm. Hence, the cell wall is a secretory product of a plant cell cytoplasm. Immediately after nuclear division, the phragmoplast or cell plate appears across the equator of the cell. At the end of mitosis, granules arising from the Golgi complex arrange themselves on the equator of the cell. They then fuse to form the cell plate. The cell plate grows in thickness by the addition of new material from the complex and becomes cell wall.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 9

Nucleoplasm is continuous with cytoplasm through-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 9

In eukaryotic cells, nucleus is a membrane bound organelle. It is surrounded by double membrane. The nucleus communicates with the surrounding cell cytoplasm through the nuclear pores.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 10

Role of nucleus in morphological differentiation was discovered in-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 10

In his experiments, Hammerling grafted the stalk of one species of Acetabularia onto the foot of another species.

In all cases, the cap that eventually developed on the grafted cell matched the species of the foot rather than that of the stalk.

 In this example, the cap that is allowed to grow on the grafted stalk looks like the base species one... A. mediterranea

This experiment shows that the base is responsible for the type of cap that grows. The nucleus that contains genetic information is in the base, so the nucleus directs cellular development.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 11

Which one is not a part of nucleus-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 11

Centrosome is a small body located near the nucleus. It has a dense center and radiating tubules. During cell division (mitosis), the centrosome divides and the two parts move to opposite sides of the dividing cell and produce microtubules.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 12

The size of the nucleolus is large where-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 12
Explanation:
The nucleolus is a distinct region within the nucleus of a cell that is responsible for the production and assembly of ribosomes, the cellular structures responsible for protein synthesis. The size of the nucleolus can vary depending on the level of protein synthesis occurring in the cell.
- A: Protein synthesis is active: When protein synthesis is active, the nucleolus tends to be larger in size. This is because ribosomes are actively being produced and assembled in the nucleolus to facilitate protein synthesis.
- B: Protein synthesis is less: When protein synthesis is less active, the nucleolus tends to be smaller in size. This is because there is a reduced need for ribosome production and assembly.
- C: No protein synthesis occurs: If no protein synthesis occurs, it is unlikely that a nucleolus would be present in the cell. The nucleolus is specifically involved in the production and assembly of ribosomes, which are essential for protein synthesis.
- D: None of the above: The correct answer is A, as explained above.
In summary, the size of the nucleolus is large when protein synthesis is active, as it plays a crucial role in ribosome production and assembly.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 13

Aerobic respiration is performed by-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 13

Mitochondria, organelles specialized to carry out aerobic respiration, contain an inner membrane folded into cristae, which form two separate compartments: the inner membrane space and the matrix. The Krebs Cycle takes place in the matrix. The electron transport chain is embedded in the inner membrane and uses both compartments to make ATP by chemiosmosis. Mitochondria have their own DNA and ribosomes, resembling those of prokaryotic organisms.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 14

Mitochondria are most abundant in-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 14

Heart muscle cells have high number of mitochondria(5000 mitochondria per cell).That is because constantly beating heart works more than any other organ in our body. Heart cells have a high demand for ATP to keep pumping the blood 24 by 7.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 15

Cytochrome oxidases are found-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 15

In healthy cells, cytochrome c (Cyt c) is located in the mitochondrial intermembrane/intercristae spaces, where it functions as an electron shuttle in the respiratory chain and interacts with cardiolipin (CL)

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 16

Small particles present on inner mitochondrial membrane are called-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 16

Option ( c)  Elementary particles. 

 Explanation :- 

Oxysomes refers to small round structures present within the folds of the cristae of the inner mitochondrial membrane. They are called elementary particles or Parson’s particle or Fernandez-Moran particle or F0F1 – particles.

Mitochondria consists of about 104-105 oxysomes.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 17

Lysosomes containing inactive enzymes are called-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 17
Answer:
The correct answer is A: Primary lysosomes.
Lysosomes are membrane-bound organelles found in animal cells. They contain digestive enzymes that break down various macromolecules, including proteins, lipids, carbohydrates, and nucleic acids. However, these enzymes need to be kept inactive within the lysosomes to prevent them from damaging the cell.
Primary lysosomes are newly formed lysosomes that contain inactive enzymes. They are formed through the process of packaging and sorting of enzymes in the Golgi apparatus.
Here is a detailed explanation of the options:
A. Primary lysosomes: These are newly formed lysosomes that contain inactive enzymes. They are the first stage in the formation of lysosomes and are responsible for storing the enzymes before they are activated.
B. Secondary lysosomes: These are lysosomes that have fused with other vesicles or endosomes containing material to be digested. They contain active enzymes and are involved in the degradation of cellular waste and foreign material.
C. Residual bodies: These are lysosomes that have completed the digestion process and contain undigested material. They are sometimes referred to as "garbage bags" of the cell.
D. Autophagosomes: These are double-membrane vesicles that sequester damaged organelles or cytoplasmic components for degradation. They fuse with lysosomes to form autolysosomes, where the enclosed material is digested.
To summarize, the correct answer is A: Primary lysosomes, as they are the lysosomes containing inactive enzymes.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 18

Which of the following statements best describes the functional characteristics of lysosomes-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 18

Lysosome is called suicidal bag hence contains enzymes which are capable of dissolving cellular apparatus.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 19

Lysosomes are called "suicide bags" because they have-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 19

Lysosomes are small vesicles which are bounded by a single membrane and contain hydrolytic enzyme in form of crystalline granules.
These enzymes are digestive enzymes also termed as ‘acid hydrolases'. Lysosomes are called suicide bags because of presence of these large number of acid hydrolases in them.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 20

In which of the following cells the endoplasmic reticulum is absent-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 20

To determine in which of the following cells the endoplasmic reticulum (ER) is absent, we need to analyze each option.
A: Kidney cells
- Kidney cells are responsible for filtering waste products from the blood and producing urine.
- These cells require the synthesis and transport of various proteins, which is facilitated by the endoplasmic reticulum.
- Therefore, the endoplasmic reticulum is present in kidney cells.
B: Liver cells
- Liver cells, or hepatocytes, perform a wide range of functions, including detoxification and protein synthesis.
- The endoplasmic reticulum, specifically the smooth ER, is involved in the detoxification process and the synthesis of lipids.
- Therefore, the endoplasmic reticulum is present in liver cells.
C: Mammalian mature erythrocytes
- Mammalian mature erythrocytes, or red blood cells, are specialized cells that transport oxygen to tissues.
- These cells lack a nucleus and most organelles, including the endoplasmic reticulum.
- The absence of endoplasmic reticulum allows for more space to accommodate hemoglobin, the protein responsible for oxygen transport.
- Therefore, the endoplasmic reticulum is absent in mammalian mature erythrocytes.
D: Mammalian eye cells
- The term "mammalian eye cells" is quite broad, as the eyes are composed of various cell types, including photoreceptor cells, lens cells, and retinal pigment epithelial cells.
- Each of these cell types has specific functions related to vision and may require the presence of endoplasmic reticulum for protein synthesis or other cellular processes.
- Without more specific information, it is not possible to definitively determine whether the endoplasmic reticulum is present or absent in mammalian eye cells.
Therefore, based on the given options, the correct answer is C: Mammalian mature erythrocytes where the endoplasmic reticulum is absent.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 21

If cells are broken up and sedimented by centrifugation, the new structures formed in
one of the fraction is-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 21

Microsomes are the structures formed when cells are broken up in the laboratory. Differential centrifugation can be used to separate them from other cellular debris. They are used to imitate the activity of the endoplasmic reticulum in a test tube. They are also used to perform experiments that require protein synthesis on a membrane thus aiding in understanding the process of protein formation on the endoplasmic reticulum. 

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 22

Which of the following enzyme is characteristic of Golgi complex-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 22

Glycosyl transferases are enzymes that catalyze the formation of the glycosidic linkage to form a glycoside. These enzymes utilize 'activated' sugar phosphates as glycosyl donors, and catalyze glycosyl group transfer to a nucleophilic group, usually an alcohol.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 23

The endoskeleton of the cell is made up of-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 23

The Endoplasmic reticulum (ER) is a type of organelle found in eukaryotic cells that forms an interconnected network of flattened, membrane-enclosed sacs or tube-like structures know as cisternae. Hence it forms endoskeleton.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 24

Match the following

1. Microtubules - Structural component of cilia

2. Centrioles - Store hydrolases

3. Peroxisomes - Stores carbohydrate, fats and proteins in plants

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 24

Microtubules are the structural component of cilia.
Centrioles play role in cell division.
Perioxisomes contain enzymes that break down long and branched fatty acid chains, amino acids, and polyamines.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 25

Genome is-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 25

A genome can be defined as a set of genes present in a cell or organism or also it can also be said as a haploid set of chromosomes in a cell. Basically, it is a complete set of DNA  which includes all the genes.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 26

The carbohydrates which project out of the lipid bilayer in animal cell membrane are linked to -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 26
The carbohydrates which project out of the lipid bilayer in animal cell membrane are linked to:
- Lipids only
- Proteins only
- Peptidoglycan
- Both lipid & protein
Answer: D. Both lipid and protein
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 27

In living cells mitochondria can be stained with-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 27

Janus green is a basic dye used in straining mitochondria

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 28

The outer membrane of mitochondria is -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 28
The outer membrane of mitochondria is less proteinaceous.

The outer membrane of mitochondria is a selectively permeable barrier that separates the interior of the mitochondria from the cytoplasm. It plays a crucial role in regulating the transport of molecules in and out of the mitochondria. Here are some key points explaining why the outer membrane is less proteinaceous:


- Composition: The outer membrane is composed of a phospholipid bilayer, similar to the plasma membrane of cells. It contains a variety of proteins that are involved in various functions, such as transport, metabolism, and signaling. However, compared to the inner membrane of mitochondria, the outer membrane has a lower protein content.
- Porins: One of the unique features of the outer membrane is the presence of porin proteins. These porins form channels that allow the passage of small molecules, such as ions and metabolites, across the membrane. The presence of porins contributes to the lower protein content of the outer membrane.
- Contact sites: The outer membrane of mitochondria is in close proximity to the endoplasmic reticulum (ER) and forms contact sites with it. These contact sites are regions where the membranes of the mitochondria and the ER are closely apposed. They play a role in lipid exchange and facilitate communication between the two organelles. The presence of contact sites further reduces the protein content of the outer membrane.
In summary, the outer membrane of mitochondria is less proteinaceous compared to the inner membrane. Its unique composition, including the presence of porins and contact sites with the ER, contributes to its lower protein content.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 29

Mitochondrial outputs are -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 29
Mitochondrial outputs:
- ATP: Adenosine triphosphate is produced during cellular respiration in the mitochondria. ATP is the primary source of energy for cellular processes.
- CO2: Carbon dioxide is a byproduct of cellular respiration. It is produced during the breakdown of glucose in the mitochondria.
- H2O: Water is another byproduct of cellular respiration. It is formed as a result of the electron transport chain in the mitochondria.
Therefore, the correct answer is C: ATP, CO2, H2O.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 30

The overcoat of the plasma membrane is the handiwork of -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 30

The overcoat of the plasma membrane means phospholipids. And the function of the golgi apparatus is to synthesise lipids and proteins. Thus, it could be said that the overcoat of the plasma membrane is the handiwork of the golgi apparatus.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 31

Find out the incorrect statement -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 31
Incorrect Statement: C: Both mitochondrial membranes are ultrastructurally similar.

The incorrect statement in the given options is C. Let's break down the options and explain why the other statements are correct:
A: The inner mitochondrial membrane possesses succinic dehydrogenase and cytochrome oxidase.
- Succinic dehydrogenase and cytochrome oxidase are enzymes involved in the electron transport chain, which takes place in the inner mitochondrial membrane. Therefore, this statement is correct.
B: The membrane-bound Krebs cycle enzyme is succinic dehydrogenase.
- Succinic dehydrogenase is indeed an enzyme involved in the Krebs cycle, also known as the citric acid cycle. This cycle takes place in the mitochondrial matrix, not in the membrane. However, succinic dehydrogenase is a key enzyme in the Krebs cycle, so this statement is correct.
C: Both mitochondrial membranes are ultrastructurally similar.
- This statement is incorrect. Mitochondria have two membranes - an outer membrane and an inner membrane. These membranes have different compositions and functions. The outer mitochondrial membrane is permeable and allows the passage of molecules, while the inner mitochondrial membrane is highly impermeable and houses the electron transport chain and ATP synthesis. Therefore, the two membranes are not ultrastructurally similar.
D: Mitochondrial cristae are sites of oxidation-reduction reactions.
- This statement is correct. The inner mitochondrial membrane is folded into structures called cristae, which increase the surface area for oxidative phosphorylation. The oxidation-reduction reactions of the electron transport chain occur on the cristae, leading to the production of ATP.
In conclusion, the incorrect statement is C: Both mitochondrial membranes are ultrastructurally similar. The other statements (A, B, and D) are correct.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 32

Which is an incorrect statement -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 32

Centrioles are paired barrel-shaped organelles located in the cytoplasm of animal cells near the nuclear envelope. Centrioles play a role in organizing microtubules that serve as the cell's skeletal system. They help determine the locations of the nucleus and other organelles within the cell.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 33

Which of the following statements regarding cilia is not correct–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 33

Microtubules of cilia are composed of tubulin

Cilia are minute, harilike processes on the surface of protozoans or of metazoans cells ehich by their motion accomplish locomotion or produce a current. Each cilium contains a peripheral circle of nine doublet microtubules arranged around two single microtubules. Each microtubule is composed of tubulin proteins.

Although the mechanism of ciliary movement is not completely under stood. It is known that the microtubules behave as sliding filament that move past one another much like the sliding filaments of vertebrate skeletal muscle.

The fluxes of Ca2+ across the membrance is not responsible for controlling the organized beating or cilia.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 34

Selecting the wrong statement from the following–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 34
The correct statement is A: Both chloroplasts and mitochondria have an internal compartment, the thylakoid space bounded by the thylakoid membrane.
Explanation:

  • Statement A: Both chloroplasts and mitochondria have an internal compartment, the thylakoid space bounded by the thylakoid membrane.

  • Chloroplasts are found in plant cells and are responsible for photosynthesis, while mitochondria are found in both plant and animal cells and are responsible for cellular respiration.

  • Both chloroplasts and mitochondria have an internal compartment called the thylakoid space, which is bounded by the thylakoid membrane.

  • The thylakoid space is where the light-dependent reactions of photosynthesis occur in chloroplasts.

  • The thylakoid membrane contains the pigments and proteins necessary for photosynthesis.

  • Statement A is correct because it accurately describes the internal compartment of both chloroplasts and mitochondria.

  • Statement B: Both chloroplasts and mitochondria contain DNA.

  • Statement B is correct. Both chloroplasts and mitochondria have their own DNA, separate from the DNA found in the nucleus of the cell.

  • Statement C: The chloroplasts are generally much larger than mitochondria.

  • Statement C is incorrect. Chloroplasts and mitochondria vary in size depending on the cell type and organism. While chloroplasts can be larger in some cases, mitochondria can also be comparable or larger in size.

  • Statement D: Both chloroplasts and mitochondria contain an inner and an outer membrane.

  • Statement D is correct. Both chloroplasts and mitochondria have a double membrane structure, consisting of an outer membrane and an inner membrane.

  • The outer membrane surrounds the organelle, while the inner membrane forms various compartments and contains proteins involved in energy production.


Overall, the correct statement is A: Both chloroplasts and mitochondria have an internal compartment, the thylakoid space bounded by the thylakoid membrane.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 35

All the following statement are correct except–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 35

Peroxisomes are cytoplasmic organelles that play a central role in break down of fatty acids and other oxidation reactions in the cell.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 36

How many divisions will occur in an isolated tip cell to form 128 cells -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 36

A single mitotic division of one cell produces two cells. 2nd division of this two cells produces 4 cells and so on. 2n = Number Of cells after n divisions. Thus 7 generations of mitosis yields 128 cells from a single cell.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 37

Synthesis of proteins for formation of spindle fibres takes place in -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 37

The synthesis of proteins for formation of spindle fibers takes place in G2 phase. G2 phase, or pre-mitotic phase is the third and final subphase of Interphase in the cell cycle directly preceding mitosis. It follows the successful completion of S phase, during which the cells DNA is replicated.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 38

O18 was used in H2O to prove that O2 comes from H2O in photosynthesis by Ruben and
Kamen. C14 was used by Calvin to discover dark reaction. N15 is used in the study of–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 38

To determine the role of N15 in the study of DNA replication, we need to understand the significance of isotopes in scientific research and the specific applications of N15.
1. Isotopes:
- Isotopes are atoms of the same element that have different numbers of neutrons in their nuclei.
- Isotopes can be used as tracers in experiments to track the movement or transformations of atoms or molecules.
2. N15:
- N15 is a heavier isotope of nitrogen, with an extra neutron compared to the more common N14 isotope.
- N15 can be used as a tracer in experiments to study the process of DNA replication.
3. DNA Replication:
- DNA replication is the process by which a cell duplicates its DNA before cell division.
- It is essential for the accurate transmission of genetic information from one generation to the next.
- Understanding the mechanisms and regulation of DNA replication is crucial in fields like genetics and molecular biology.
4. N15 and DNA Replication:
- N15 can be incorporated into the DNA molecule during replication.
- By labeling the DNA with N15, researchers can track the movement of the labeled DNA and study the process of replication.
- The incorporation of N15 into DNA can be measured using various techniques like mass spectrometry.
5. Conclusion:
- N15 is used in the study of DNA replication as a tracer to understand the mechanisms and regulation of this essential biological process.
- By labeling DNA with N15, researchers can track the movement of the labeled DNA and gain insights into the replication process.
Therefore, option B: DNA replication is the correct answer.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 39

Smallest phase of mitosis is -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 39

Cell division does not take a long time. Prophase is the longest phase of mitosis, but it occurs faster than interphase. Anaphase is the shortest phase of mitosis. In anaphase, the sister chromatids are pulled apart to opposite ends of the cell.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 40

Which of the following is the better explanation of earlier discovery of the "Nucleus" than the "Cell Theory"–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 40
Explanation of earlier discovery of the "Nucleus" than the "Cell Theory":

  • A: Nucleus is a more important structure than cytoplasm.

  • This explanation does not directly address the earlier discovery of the nucleus. The importance of the nucleus does not necessarily imply that it was discovered before the cell theory.


  • B: Robert Brown had a better microscope.

  • This explanation suggests that Robert Brown's microscope was the reason for the earlier discovery of the nucleus. However, it does not provide any evidence or explanation as to why his microscope was better or how it specifically aided in the discovery of the nucleus.


  • C: Nuclei take a darker stain than other parts of a cell.

  • This explanation suggests that the ability to stain nuclei darker than other parts of a cell led to their earlier discovery. While staining techniques may have played a role in visualizing the nucleus, it does not fully explain why the nucleus was discovered earlier than the cell theory.


  • D: Nucleus is a visible body while cell theory is an abstract generalization.

  • This explanation provides a more plausible reason for the earlier discovery of the nucleus. The nucleus is a visible structure that can be observed under a microscope, while the cell theory is a conceptual framework that requires a deeper understanding of cell organization. Therefore, it is more likely that the visible nature of the nucleus contributed to its earlier discovery compared to the abstract concept of the cell theory.



Conclusion:
Based on the explanations provided, option D - "Nucleus is a visible body while cell theory is an abstract generalization" is the better explanation for the earlier discovery of the nucleus compared to the cell theory. The visible nature of the nucleus made it easier to observe and study, while the cell theory required a more abstract understanding of cellular organization.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 41

Choose the correct statement–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 41
Statement Analysis:
The statement is asking to choose the correct statement about ribosomal subunits.
Options:
A: Ribosomal subunits are united during protein synthesis.
B: Ribosomal subunits always remain united.
C: Ribosomal subunits are united in the nucleus during r-RNA synthesis.
D: All are correct statements.

The correct statement is option A: Ribosomal subunits are united during protein synthesis.
Here is a detailed explanation:
Ribosomal Subunits:
- Ribosomal subunits are the components of ribosomes, which are responsible for protein synthesis.
- Ribosomes are composed of two subunits, the large subunit and the small subunit, which come together during protein synthesis.
Option Analysis:
A: Ribosomal subunits are united during protein synthesis.
- This statement is correct. Ribosomal subunits join together during protein synthesis to form a functional ribosome.
B: Ribosomal subunits always remain united.
- This statement is incorrect. Ribosomal subunits come together during protein synthesis and can separate when not actively involved in protein synthesis.
C: Ribosomal subunits are united in the nucleus during r-RNA synthesis.
- This statement is incorrect. Ribosomal subunits are synthesized separately in the nucleolus of the nucleus and then transported to the cytoplasm, where they unite during protein synthesis.
D: All are correct statements.
- This statement is incorrect as option B and option C are incorrect.
Conclusion:
The correct statement is option A: Ribosomal subunits are united during protein synthesis.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 42

Which of the following observations most strongly support the view that mitochondria have elctron transport system/enzymes–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 42

In the inner membrane of the mitochondria, electrons from NADH and FADH2​ go through the electron transport chain to O2​, to yield water. It consists of a series of reactions that transfer electrons from donors to acceptors and couples this exchange with the transfer of H+ ions across the membrane creating an electrochemical proton gradient which drives the formation of a molecule that stores energy in the form of highly strained bonds. This energy rich molecule is adenosine triphosphate (ATP). The enzyme responsible for ATP synthesis is ATP synthase.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 43

What is correct ?

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 43
Explanation:
The correct answer is D, as all the statements mentioned in options A, B, and C are correct.
Here is a detailed explanation of each statement:
A:
- Nucleosomal organization provides a chromatin fiber about 10 nm in thickness.
- Chromatin fibers are further condensed to produce a solenoid of 30 nm diameter.
B:
- The solenoid structure further coils to produce a chromatin fiber of 200 nm.
- The chromatin fiber then condenses to form a chromatid with a diameter of 700 nm.
C:
- All the folded loops of chromatin are held together.
Therefore, option D, which includes all the statements, is the correct answer.
To summarize:
- Nucleosomal organization forms chromatin fibers of about 10 nm thickness.
- Chromatin fibers condense to produce a solenoid structure with a diameter of 30 nm.
- The solenoid structure further coils to form a chromatin fiber of 200 nm.
- The chromatin fiber condenses to produce a chromatid with a diameter of 700 nm.
- All the folded loops of chromatin are held together.
Remember, when answering multiple-choice questions, carefully read each option and evaluate if it is correct or incorrect.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 44

The eukaryotic cells are essentially two envelope system because they contain–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 44
Explanation:
The eukaryotic cells are essentially two envelope system because they contain a plasma membrane and a nuclear membrane. Here is a detailed explanation:
1. Eukaryotic Cells:
- Eukaryotic cells are complex cells that make up organisms such as plants, animals, fungi, and protists.
- They are characterized by having a true nucleus that contains genetic material.
2. Two Envelope System:
- The two-envelope system refers to the presence of two membranes surrounding the nucleus of eukaryotic cells.
- These membranes are the plasma membrane and the nuclear membrane.
3. Plasma Membrane:
- The plasma membrane, also known as the cell membrane, is a selectively permeable barrier that surrounds the entire cell.
- It consists of a phospholipid bilayer embedded with proteins.
- The plasma membrane regulates the movement of substances in and out of the cell.
4. Nuclear Membrane:
- The nuclear membrane, also known as the nuclear envelope, is a double membrane structure that surrounds the nucleus.
- It consists of an outer membrane and an inner membrane with a narrow space between them.
- The nuclear membrane contains nuclear pores, which allow the exchange of materials between the nucleus and the cytoplasm.
5. Function:
- The two-envelope system of eukaryotic cells provides additional protection and compartmentalization for the nucleus.
- It helps regulate the flow of molecules in and out of the nucleus, ensuring proper cellular functions and maintaining the integrity of the genetic material.
Therefore, the correct answer is B: Plasma membrane and Nuclear membrane.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 45

Which of the following statement justifies that "the cell is a self-contained unit"–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 45
Explanation:
The statement "the cell is a self-contained unit" means that the cell is capable of carrying out all essential biological processes on its own. Let's analyze each option to see which one justifies this statement:
A: It independently carries out all fundamental biological processes:
- This option suggests that the cell is capable of performing all necessary biological processes without relying on external factors or assistance. It implies that the cell is self-sufficient in carrying out its functions.
B: It oxidizes food molecules to produce energy and utilizes this energy to synthesize complex molecules:
- This option highlights the cell's ability to obtain energy from food molecules through oxidation and utilize that energy to synthesize complex molecules. This process of energy production and utilization is a fundamental biological process that the cell performs independently.
C: Reproduces with similar hereditary properties:
- While reproduction is an essential biological process, it does not directly justify that the cell is a self-contained unit. Reproduction involves the interaction of cells with other cells or the environment, and it does not necessarily demonstrate the cell's ability to carry out all biological processes independently.
D: All of the above:
- This option includes both options A and B, which justify that the cell is a self-contained unit. It encompasses the cell's independence in carrying out all fundamental biological processes and its ability to generate energy and synthesize complex molecules. Therefore, option D is the correct answer.
In conclusion, option D justifies the statement "the cell is a self-contained unit" as it encompasses the cell's independence in carrying out all essential biological processes and its ability to generate energy and synthesize complex molecules.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 46

The significance of phospholipid bilayer in plasma membrane is to form–

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 46

Bilayer in the plasma membrane because the outer membrane of the bilayer is hydrophilic so that it protects inner hydrophobic layer which should not face water

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 47

A bivalent consists of

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 47

The two replicated homologous chromosomes associate to form a bivalent. It is also known as tetrad and It is mainly formed during the pachytene stage of the meiosis. They undergo chiasmata formation for recombination

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 48

Muramic acid is present in cell walls of -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 48

Muramic acid (N-acetyl muramic acid, that constitutes peptidoglycan) is a typical cell wall component of bacteria.
Hence, from the given options it is clear that only bacteria / blue green algae would be having muramic acid, as the cell wall component.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 49

Growth of cell wall during cell elongation takes place by -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 49
Explanation:
During cell elongation, the growth of the cell wall occurs through a process known as cell wall expansion. This expansion can take place through two main mechanisms: apposition and intussusception.
Apposition:
- Apposition refers to the addition of new cell wall material adjacent to the existing cell wall.
- In this process, new cell wall material is synthesized and deposited on the outer surface of the existing cell wall.
- This results in an increase in the thickness of the cell wall, leading to cell elongation.
Intussusception:
- Intussusception involves the insertion of new cell wall material within the existing cell wall.
- In this process, new cell wall material is synthesized and inserted between the existing cell wall layers.
- This results in an increase in the surface area of the cell wall, allowing for cell elongation.
Both A and B:
- The growth of the cell wall during cell elongation can occur through both apposition and intussusception.
- Apposition and intussusception are not mutually exclusive processes and can both contribute to cell wall expansion.
Conclusion:
- The growth of the cell wall during cell elongation can occur through both apposition and intussusception.
- Both processes play a role in the expansion and elongation of the cell wall, allowing for cell growth and development.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 50

Plasmodesmata are -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 50

Plasmodesmata connect protoplasm of adjacent cells.
Continuity in cytoplasm of adjacent cells remains by
plasmodesmata.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 51

Which element mainly occurs in middle lamella -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 51

Middle lamella is a pectin layer and is made up of calcium and magnesium pectates. Its function is to strengthen the cell wall of two adjoining cells. Main element present in the middle lamella is calcium.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 52

Cell membrane is composed of -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 52
Cell membrane composition:
The cell membrane, also known as the plasma membrane, is a vital component of all cells. It acts as a barrier that separates the internal contents of the cell from the external environment. The cell membrane is composed of various components, primarily proteins, phospholipids, and some carbohydrates.
Proteins:
- Integral Proteins: These proteins are embedded within the cell membrane and span across its entire width. They are responsible for transporting molecules in and out of the cell, as well as facilitating cell signaling and communication.
- Peripheral Proteins: These proteins are found on the surface of the cell membrane and are not embedded within it. They play a role in cell structure, cell adhesion, and cell signaling.
Phospholipids:
- Phospholipids are the main building blocks of the cell membrane. They form a lipid bilayer structure with hydrophobic tails facing inward and hydrophilic heads facing outward. This arrangement provides a stable barrier between the inside and outside of the cell.
Carbohydrates:
- Carbohydrates are present on the outer surface of the cell membrane, attached to proteins and lipids. They form glycoproteins and glycolipids, which are involved in cell recognition, cell adhesion, and immune responses.
Conclusion:
The cell membrane is composed of proteins, phospholipids, and some carbohydrates. These components work together to maintain the integrity of the cell and regulate the movement of molecules in and out of the cell.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 53

Which of the following is main enzyme of plasma membrane -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 53

ATPase are a class of enzymes that catalyze the dephosphorylation of ATP into ADP and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur. This process is widely used in all known forms of life. Such enzymes are integral membrane proteins anchored within biological membranes (plasma membrane), and move solutes across the membrane, typically against their concentration gradient.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 54

Percentage of intrinsic proteins in the total proteins of plasma membrane -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 54

About 70% of the proteins of the plasma membrane are intrinsic proteins. The intrinsic proteins, as their name implies, are firmly embedded in the phospholipid bilayer. Almost all intrinsic proteins contain special amino acid sequences.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 55

Cell wall was discovered by -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 55

Cell wall was discovered by Robert Hooke, in 1665, when he saw an empty box like compartments in a very thin slice of cork under his microscope. He wrote a book Micrographia and coined the term Cellula which was later on changed into cells. Robert Hooke thought cells to be passages for conducting fluids.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 56

Cell wall is -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 56

The cell wall is dead at maturity in plants.Hence,cell wall cannot regulate entry or exit of solute or solvents particals across it .In other words, the cell wall is fully permeable to both solute and solvents molecules.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 57

Decision of cell division occurs at -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 57

At the End of G1 Phase cell decides to further divide or to be a Permanent cell by going to G0 phase which is also known as Quiscent Stage.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 58

Crossing over takes place on -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 58
Explanation:
The process of crossing over, also known as recombination, occurs during meiosis, specifically during prophase I. This process involves the exchange of genetic material between homologous chromosomes, resulting in genetic variation in offspring.
Key Points:
- Crossing over takes place during meiosis.
- It occurs at the four stranded stage, also known as the tetrad stage.
- The tetrad stage refers to the alignment of homologous chromosomes, which consists of two pairs of sister chromatids.
- During crossing over, sections of genetic material are exchanged between non-sister chromatids of homologous chromosomes.
- This exchange of genetic material leads to the formation of new combinations of genes.
- Crossing over promotes genetic diversity and increases the chances of offspring survival in changing environments.
Conclusion:
To summarize, crossing over takes place during meiosis at the four stranded stage, where sections of genetic material are exchanged between homologous chromosomes. This process promotes genetic diversity and contributes to the survival and adaptation of offspring.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 59

Carbohydrates which present in the cell membrane take part in -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 59

Carbohydrates which are present in the cell membrane take part in cell recognition. Cell recognition is defined as an active process giving rise to a specific response. 

Cell adhesion is a good example of cell recognition when it can be demonstrated that the adhesion is mediated by molecules having specific binding properties. Such cell adhesion molecules have now been identified in several cellular systems. Carbohydrates, or sugars, are sometimes found attached to proteins or lipids on the outside of a cell membrane.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 60

Plasma membrane is fluid structure due to presence of -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 60

The plasma membrane or cell membrane is the outer covering of all cells but in a plant cell, it is present below the cell wall. It is mainly composed of phospholipid bilayer structure with the embedded proteins. The fluid nature of membranes is due to the lipids. The lipids can be saturated or unsaturated.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 61

When the prophase chromosome are stained
with acetocarmine they take differential
staining. This phenomenon is called -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 61

Heterochromatin is closely associated with the nucleolus. So, when the prophase chromosome are stained with acetocarmine they take differential staining due to presence os heterochromatin and euchromatin regions. This phenomenon is called as heteropycnosis.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 62

Longest phase of mitosis is -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 62

Cell division does not take a long time. Prophase is the longest phase of mitosis, but it occurs faster than interphase. Anaphase is the shortest phase of mitosis. In anaphase, the sister chromatids are pulled apart to opposite ends of the cell

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 63

Amphipathic molecule in plasma membrane is -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 63

The lipids in the plasma membrane are phospholipids with one polar hydrophilic head and two nonpolar hydrophobic tail. Thus, the lipids are amphipathic. The hydrophilic head is exposed to the surface whereas the hydrophobic tail is embedded in the inner region of the membrane.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 64

The average thickenss of plasma membrane is -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 64

The electron microscopic studies reveal that a typical cell/plasma membrane is 75-100 Å (7.5-10.0 nm) in thickness. The cell membranes are primarily composed of lipids (about 40%) & proteins (about 60%).

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 65

Unit membrane model of plasma membrane
was proposed by -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 65

Robertson proposed unit membrane concept for biological membranes. According to this concept, the biological membrane is a lipid bilayer surrounded on either side by proteins with a difference in their type for the outer and inner side. All biomembranes have a trilaminar structure with an electron transparent lipid bilayer (35 A˚) lying sandwiched between electron dense protein layers (20 A˚ each).

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 66

Pit membrane of simple pit is formed by -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 66

Pits are discontinuities in the secondary cell wall. there are two main types of pits – simple and bordered. All pits have two essential components – the pit cavity and the pit membrane. In the simple pit, the cavity is nearly constant in width. In the bordered pit, the cavity narrows towards the cell lumen; typically, the membrane is arched over by the secondary cell wall. The pit membrane cosists of primary wall and middle lamella. As a rule, pits in the walls of adjoining cells appear in pairs called pit-pairs, and the common membrane is therefore composed of two primary walls and middle lamella.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 67

Term plasmodesmeta was first used by -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 67

In plants, cell wall possesses minute cytoplasmic bridges between adjacent cells. They are called plasmodesmata. Term plasmodesmata was first used by Strasburger in 1901. So, the correct answer is 'Strasburger'.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 68

Primary cell wall formed by -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 68

Intussusception is the growth of the cell wall by the deposition of cellulose. The plant cell wall is a product of protoplasmic activity and in the higher plants its development begins with the formation of the cell plate, immediately after nuclear division. This thin cell plate quickly acquires the form of a primary cell wall, which is defined as the structure which encloses the protoplasts during the period of cell enlargement. Once, the period of cell enlargement is over the cell wall becomes thickened to become the secondary wall. The secondary wall is regarded as the structural component of the plant.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 69

Cell wall of prokaryotes is made up of -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 69
Cell wall of prokaryotes is made up of:
- Mucopeptide: The cell wall of prokaryotes is primarily composed of mucopeptide, also known as peptidoglycan. It is a unique polymer that consists of alternating units of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), which are cross-linked by short peptide chains. The mucopeptide layer provides strength and rigidity to the cell wall and protects the bacteria from osmotic lysis.
- Chitin, cellulose, and glucose amine are not found in the cell wall of prokaryotes.
- Chitin: Chitin is a polysaccharide that is commonly found in the exoskeleton of arthropods and the cell walls of fungi, but it is not present in prokaryotic cell walls.
- Cellulose: Cellulose is a polysaccharide that is the main structural component of plant cell walls. It is not present in prokaryotic cell walls.
- Glucose amine: Glucose amine is a sugar derivative, but it is not a major component of prokaryotic cell walls.
Therefore, the correct answer is D) Mucopeptide.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 70

Butter Sandwich model of plasma membrane
was proposed by -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 70

Sandwich or Lamellar models explained that cell membranes contain both proteins and lipids in distinct layers. According to the Danielli and Davson model, plasma membrane consists of a double phospholipid layer and is surrounded on either side by a layer of hydrated globular proteins or P-L-L-P structure. The hydrophobic or non polar tails of the two lipid layers are towards the centre.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 71

The Singer’s Model of Plasma membrane
differs from the Robertson’s model in the -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 71

Robertson proposed a trilaminar structure for plasma membrane which comprised of an electron transparent lipid bilayer sandwiched between electron dense protein layers. Singer and Nicolson proposed a fluid mosaic model in which the proteins are interspersed and floating like the mosaic on a lipid bilayer.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 72

Ingestion of solid food by plasma membranes
is called

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 72

Phagocytosis means “cellular eating” while Pinocytosis means “cellular drinking”. Pinocytosis and Phagocytosis are the two categories of Endocytosis. Both are the active process and requires energy (ATP) as adenosine triphosphate for the uptake of materials. Phagocytosis is an intake of solid particles with the formation of vesicles called phagosomes, while pinocytosis is the intake of liquid particles with the formation of vesicles called pinosomes.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 73

In order to find out quickly whether the cells
are living one must observe -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 73

Cytoplasmic matrix is often differentiated into outer gel part called as ectoplasm and inner sol part called as endoplasm. In a living cell, the endoplasm is usually in perpetual motion called as cyclosis or cytoplasmic or protoplasmic streaming. So, the movement of cytoplasm can be used find out whether the cells are living or not.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 74

Which one is widely distributed in a cell -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 74
Answer:
Distribution of Components in a Cell:
In a cell, different components are distributed in varying amounts and locations. Among the given options, RNA is widely distributed in a cell. Here is a detailed explanation:
1. DNA:
- DNA (Deoxyribonucleic Acid) is the genetic material found in the nucleus of a cell.
- It is responsible for storing and transmitting genetic information.
- While DNA is present in all cells, it is not widely distributed throughout the cell.
2. RNA:
- RNA (Ribonucleic Acid) is a nucleic acid that is involved in various cellular processes.
- It is synthesized from DNA and plays a crucial role in protein synthesis.
- RNA is present in different forms, such as messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).
- It is found in the nucleus, cytoplasm, and various organelles of the cell.
- RNA is involved in both transcription (DNA to RNA) and translation (RNA to protein), making it widely distributed in the cell.
3. Plastids:
- Plastids are organelles found in plant cells and some photosynthetic organisms.
- They are responsible for various functions, such as photosynthesis, storage of pigments, and synthesis of lipids.
- Plastids are not present in all cells, and their distribution is limited to specific cell types.
4. Golgi:
- The Golgi apparatus is an organelle involved in modifying, sorting, and packaging proteins and lipids.
- It is responsible for the formation of vesicles that transport molecules to different cellular destinations.
- The Golgi apparatus is located near the nucleus but is not widely distributed throughout the cell.
In conclusion:
- Among the given options, RNA is widely distributed in a cell.
- It is involved in various cellular processes and can be found in the nucleus, cytoplasm, and various organelles of the cell.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 75

Maximum enzymes are found in -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 75

Mitochondria is the site for aerobic respiration in cell and produces energy in the form of ATP. For the formation of energy different pathways like electron transport chain, kreb's cycle are involved and operated by the different enzymes. Thus, the maximum number of enzymes are found in mitochondria.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 76

Rough E.R. mainly responsible for -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 76

Rough endoplasmic reticulum carry ribosomes on their surface. The ribosomes present on rough endoplasmic reticulum synthesize secretory proteins. The proteins required for internal use of cell are synthesized on cytoplasmic ribosomes.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 77

Besides producing secretory vesicles, the
function of golgibody is -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 77

It plays an important role in the storage, packaging and secretion of certain cell products. It is involved in the formation of lysosomes and other enzyme-containing cellular inclusions, and in the formation of secretory granules.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 78

Mitochondria supply most of the necessary
biological energy through -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 78

TCA or Tricarboxylic Acid Cycle or Krebs cycle oxidizes the compounds like acetyl-CoA obtained from carbohydrates, fats and proteins and leads to the production of carbon dioxide and energy in form of ATP.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 79

Enzymes for ETS occurs in (mitochondria)-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 79

Mitochondria are cell organelles involved in aerobic respiration. Krebs cycle occurs in the mitochondrial matrix. Krebs cycle produces reduced coenzymes which are oxidized by electron carriers of Electron Transport System or ETS to produce ATP through oxidative phosphorylation. The electron carriers of ETS are located in the inner mitochondrial membrane in eukaryotes.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 80

Mitochondrial DNA is -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 80
Mitochondrial DNA is Circular and Double-stranded
Mitochondrial DNA (mtDNA) is a unique type of DNA found in the mitochondria, which are small organelles within the cells that are responsible for energy production. Here are the key characteristics of mitochondrial DNA:
1. Circular structure:
- Unlike the linear DNA found in the nucleus, mtDNA has a circular structure.
- This circular shape allows for efficient replication and maintenance of the DNA within the mitochondria.
2. Double-stranded:
- Mitochondrial DNA consists of two strands, known as the heavy strand and the light strand.
- The two strands are complementary, meaning they can form base pairs with each other.
- This double-stranded nature is important for the stability and functioning of mtDNA.
3. Naked:
- Mitochondrial DNA is considered "naked" because it does not associate with proteins called histones.
- Unlike nuclear DNA, which is tightly wound around histones to form chromatin, mtDNA is not organized into nucleosomes.
4. Maternal inheritance:
- One interesting aspect of mtDNA is that it is primarily inherited from the mother.
- This is because the mitochondria in the sperm cells are usually destroyed after fertilization, while the mitochondria in the egg cells are passed on to the offspring.
- As a result, the mtDNA in an individual is derived from their mother's lineage.
In summary, mitochondrial DNA is circular and double-stranded, and it is considered "naked" since it is not associated with histones. Its unique characteristics play a crucial role in the functioning and inheritance of mitochondrial DNA.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 81

Which structures are responsible for lipid synthisis repectively in plants and animal cells-

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 81

Sphaerosomes are single half unit membrane covered small spherical organelles in plants which synthesize and store fats. They develop from endoplasmic reticulum. Smooth endoplasmic reticulum are devoid of ribosomes and carry out synthesis of lipids, detoxification, synthesis of steroids in animals.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 82

Which cell organelle secretes zymogen
granules -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 82

A zymogen or proenzyme is an inactive enzyme precursor. A zymogen requires a biochemical change such as a hydrolysis reaction revealing the active site, or changing the configuration to reveal the active site for it to become an active enzyme. Smooth endoplasmic reticulum secretes zymogen. The smooth endoplasmic reticulum has functions in several metabolic processes. It synthesizes lipids, phospholipids, and steroids. The general structure of the endoplasmic reticulum is a network of membranes called cisternae. These sac-like structures are held together by the cytoskeleton. The network of smooth endoplasmic reticulum allows for an increased surface area to be devoted to the action or storage of key enzymes and the products of these enzymes.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 83

Lysosomes are not helpful in -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 83

Lysosomes are useful in metamorphosis in eating away larval organs, removal of obstructions, intracellular scavenging, fertilization etc. They do not perform any biosynthetic activity, hence, are not useful in lipogenesis. Lipids are synthesized in smooth endoplasmic reticulum and spherosomes.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 84

Digestion of hormonal vesicle by lysosome
is called -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 84

Lysosomes carry a variety of hydrolytic enzymes. Lysosomes show polymorphism. There are different forms of lysosomes. Crinophagy is the term which is used to describe the disposal of excess secretory granules by lysosomes. This is a process in which excess amounts of hormone are fused with lysosomes to degrade the hormones. This digestion of the hormones is performed in the hormone vesicles

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 85

 The function of cristae in a mitochondrion is

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 85

Mitochondrial cristae are folds of the mitochondrial inner membrane that provide an increase in the surface area. This allows a greater space for processes that happen across this membrane. The electron transport chain and chemiosmosis are the processes which help produce ATP in the final steps of cellular respiration.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 86

Which of the following provides mechanical
support and shape to the cell -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 86

The endoplasmic reticulum (ER) is a system of membrane-lined channels found in all eukaryotic cells except mature erythrocytes. It constitutes more than 30 to 60 percent of total cell membranes. The membranes of ER act as an ultrastructural skeletal framework in the cell and provide mechanical support as it helps in formation and transportation of protein and lipid in membrane biogenesis.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 87

Mitochondria are site of respiration first
reported by Kingsbury and supported by
Hogeboom. Mitochondira are related with the
oxidation of -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 87

The respiration process in cells takes place in the mitochondria. Let's break down the information and explain each point in detail:
1. Mitochondria are the site of respiration:
- Respiration is the process by which cells convert nutrients into usable energy in the form of ATP (adenosine triphosphate).
- Mitochondria are double-membraned organelles found in most eukaryotic cells and are often referred to as the "powerhouses" of the cell due to their role in ATP production.
- They play a crucial role in cellular respiration, which is the process of breaking down organic molecules to produce energy.
2. First reported by Kingsbury and supported by Hogeboom:
- Kingsbury was an American biologist who first reported the association of respiration with the mitochondria in the early 1920s.
- Hogeboom, another biologist, provided further evidence supporting Kingsbury's findings.
3. Mitochondria are related to the oxidation of:
- Oxidation refers to the process of removing electrons from molecules.
- Mitochondria are involved in the oxidation of various nutrients to generate energy.
- The main nutrients that undergo oxidation in mitochondria are carbohydrates, fats, and proteins.
4. Answer: D (All the above):
- Carbohydrates: Mitochondria oxidize glucose, a type of carbohydrate, through a process called glycolysis and the citric acid cycle to produce ATP.
- Fats: Mitochondria also oxidize fatty acids, which are derived from fats, to generate ATP.
- Proteins: In certain circumstances, when carbohydrates and fats are not available, proteins can be oxidized in the mitochondria to produce energy.
In conclusion, mitochondria are the site of cellular respiration, which involves the oxidation of carbohydrates, fats, and proteins to produce energy. This was first reported by Kingsbury and supported by Hogeboom.
Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 88

Peptidyl tranferase enzyme found on -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 88

Peptidyl transferase activity is carried out by the ribosome. Peptidyl transferase activity is not mediated by any ribosomal proteins but by ribosomal RNA (rRNA), a ribozyme. Ribozymes are the only enzymes which are not made up of proteins, but ribonucleotides. All other enzymes are made up of proteins.

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 89

Which of the following transport the cell well
material from dictyosome -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 89

Microtubules transport the cell wall material from dictyosome. Microtubules are very important in a number of cellular processes. They are involved in maintaining the structure of the cell and together with microfilaments and intermediate filaments, they form the cytoskeleton

Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 90

Golgibody is absent in -

Detailed Solution for Cell Biology And Cell Division (MCQ) - Cell Cycle And Cell Division, Class 11, Biology - Question 90

Golgi body is a cellular organelle that is part of the cytoplasmic membrane system; it is composed of regions of stacked cisternae and it functions in secretory processes. Prokaryotes, mature mammalian RBCs and the akaryotes (cells without the nucleus) lack the Golgi bodies.

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