CSIR NET Life Sciences Mock Test - 8 - UGC NET MCQ

Calculation:

The area of the rectangle is 144 cm² and the sides are in the ratio 4:9.
Let the length be 4x and the breadth be 9x. 
Area of a rectangle = length × breadth gth

Therefore, the length cm and the breadth =18 cm
Perimeter of a rectangle =2 (Length Breadth)

Perimeter 

Perimeter  Perimeter cm

The formula for Arithmetic Sequence:
a_n = a₁ + (n – 1)d
According to the question
q = p + (3 - 1)d
⇒ q = p + 2d    ----(1)
And 3 = p + (5 - 1)d
⇒ 3 = p + 4d    ----(2)
Solving (1) and (2), we get
q = 3 - 2d
and p = 3 - 4d      [from (2)]
According to the question pq is minimum
= (3 - 4d) (3 - 2d) is minimum
= (9 - 18d + 8d²) is minimum
Differentiation the above equation with respect to d is 0
⇒ -18 + 16d = 0
⇒ d = 9/8
∴ The value of d is 9/8.

In 200 mixture, milk  = liter

Water in the mixture=200-160 = 40 liter

Let the quantity of mixture is taken out = 5x

Then,  

480 - 12x = 350 - 7x 

5x = 130

x = 26 

Quantity of mixture taken out = 130 liter

Given,

Aristotle was a Greek philosopher, who first classified organisms as either plant or animals. Modern biological classification has given five kingdoms.

A few plants exhibits unusual flowering phenomenon. Bamboo species is one of them, which produces flower once in their life time, generally after 50-100 years. They produce large number of fruits and die

If the cells containing plasmids are infected with helper phage, then single stranded DNA can be produced, packaged and secreted into the medium. DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person's body has the same DNA.

Pulmonary respiration is the exchange of gases between the alveoli of the lungs and the blood in the capillaries. The exchange of gases between blood and tissue cell occurs in internal respiration.

In Bacteria, when many flagella present only at one pole, are known as Lophotrichoous.

Flagella: It is a slender threadlike structure, especially a microscopic part that enables many protozoa, bacteria, spermatozoa, etc. to swim.

Parts of flagella: Bacterial flagellum is composed of three parts – filament, hook and the basal body.

Based on the number and placement of flagella on the cell, there are four types of flagellar arrangements. They are:

Enzymes are proteins or non-proteins that act as bio-catalysts. Holoenzymes comprise a prosthetic group and an apoenzyme. The prosthetic group can be either co-factors or co-enzymes. Cutting a potato is a physical change and doesn’t lead to the breakage of bonds in the enzymes present in it.

In angiosperms, the egg is devoid of wall.

In female gemetophyte, the egg apparatus is attached to the wall of embryo sac only at the micropylar end and it is surrounded by the central cell. The egg apparatus is comprised of an egg cell and two synergids. Cells of the egg apparatus and the antipodal cells are uninucleate and haploid whereas the central cell is binucleate or diploid.

Schwann cells secrete a myelin sheath.

The myelinated nerve fibres are enveloped with Schwann cells, which form a myelin sheath around the axon. The gaps between the two adjacent myelin sheaths are called Nodes of Ranvier. 

The compound that contains ionic, coordinate, and covalent bonds is ammonium chloride (NH₄Cl). Here’s how these bonds are present:

• Ionic bond: Formed between the ammonium ion (NH₄⁺) and the chloride ion (Cl^-).
• Coordinate bond: Present in the ammonium ion where one nitrogen atom shares its pair of electrons with hydrogen atoms.
• Covalent bond: Found within the ammonium ion where nitrogen and hydrogen atoms are bonded by sharing electrons.

Other compounds listed do not exhibit all three types of bonds:

• Sodium chloride (NaCl) contains only ionic bonds.
• Methane (CH₄) has only covalent bonds.
• Water (H₂O) consists of covalent bonds only.

Hence , the Correct Answer is Option A

The inner cell mass (ICM) forms within the blastocyst, prior to its implantation within the uterus. The ICM is the only pluripotent cell lineage in the blastocyst. The ICM forms the epiblast and hypoblast layers, which develop into the embryonic tissues and extraembryonic tissues, respectively.

The tiny molecules of naked circular RNA that infect plants are called viroids.

• Viroids are much smaller than viruses and do not have a protein coat.
• They cause diseases in plants by disrupting normal cell processes.
• Unlike viruses, viroids contain only RNA and no other components.

Therefore, Correct Answer is Option B.

'Palade particles' is another name for ribosomes.

• Ribosomes are non-membrane bound organelles and granular structures that was discovered by George Palade in 1953.
• They are composed of ribonucleic acid (RNA) and proteins.
• Ribosomes are protein synthesizers of a cell and they are found in both Prokaryotic and Eukaryotic cells.

Genotype-Phenotype concept was first produced by Johannsen.

The external physical characters of a trait that are expressed is called phenotype. Wilhelm Johannsen first studied heredity and proposed the difference between genotype and phenotype. According to Johannsen, the genotype of an organism is responsible for its phenotype through development and environmental effect.

The -COOH group of cellular amino acids can form Ester and amide bonds inside the cell.

The reaction of amines with esters to form amides is of fundamental importance in organic synthesis. In noncatalytic reactions, this can occur when a highly reactive ester is used, or the nucleophile is activated by harsh stoichiometric base.

Microtubules of a dividing cell form the mitotic spindle required for chromosome segregation. Microtubules in the nerve and epithelial cells play a role in organelle transport.

The internal framework of a cell (the cytoskeleton) is responsible for positioning the various organelles. This is particularly evident in polarized epithelial cells where organelles are specifically ordered from the apical to the basal end of the cell.

So, both I and II statements are correct.

Following are the properties which a biosensor should possess:

If the biosensor used in invasive, the probe must be tiny and biocompatible, having no toxic or antigenic effects.

The biosensor should be cheap, small, portable, and capable of being used by semi-skilled operators.

If the traditional methods used are encouraged and the decentralization of laboratory testing is discouraged, then there is no use of producing more biosensors. Thus, there should be a market for biosensors.

“The specificity of substrate binding is mediated by the spatial arrangement of atoms in an enzyme’s substrate binding site as well as the substrate.” This is a property of the active site of the enzyme.

In ecology, edge effects are changes in population or community structures that occur at the boundary of two or more habitats. Areas with small habitat fragments exhibit especially pronounced edge effects that may extend throughout the range. As the edge effects increase, the boundary habitat allows for greater biodiversity.

In the female reproductive cycle, the germ cell divides mitotically and produces millions of oogonia. Most of the oogonia will undergo degeneration by the process known as atresia.

Plants have the ability to grow into a complete plant from a single cell. While animals are only produced by their species and reproduction. Hence, they are more readily manipulated by genetic engineering than an animal. 

All of the above statements given in the question, are correct.
For recombination to occur, the R2 segment of the Trp DNA molecule must recombine with R3 segment of the bottom DNA molecule. R1 segment of the top molecule must recombine with R4 segment of the bottom DNA molecule.

Nucleolus is the site for synthesis of Ribosomal RNA.

• Ribosomal RNA (rRNA) is a molecule in cells that is part of protein-building organelles called ribosomes and is exported to the cytoplasm to help translate the information contained in messenger RNA (mRNA) to proteins. 
• The encoded rRNAs are of different sizes, differentiated into large or small. Each ribosome contains at least 1 large rRNA and at least 1 small rRNA. 
• In the nucleolus, large and small rRNAs combine with ribosomal proteins to form large and small ribosomal subunits (eg, 50S and 30S in bacteria, respectively).

Redifferentiation leads to the formation of secondary xylem and phloem. Redifferentiation is the maturation of dedifferentiated cells thereby specializing for a particular function. Development includes all the changes undergone by a living plant from seed emergence to death. Dedifferentiation is regaining the lost capacity of cells or tissues of plants to divide under special conditions. Differentiation is the division and growth of cells in order to mature.

Flowers contain the plant’s reproductive structures. A typical flower has four main parts - or whorls - known as the calyx, corolla, androecium, and gynoecium. The outermost whorl of the flower has green, leafy structures known as sepals. The sepals, collectively called the calyx, help to protect the unopened bud.

A selectable marker is a gene that helps in identifying successful transformants. They eliminate the growth of non-transformants and favor the growth of the desired organism. It is one of the features which facilitate cloning in a vector.