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All questions of Class 9 for UPSC CSE Exam
Living cells were discovered by- a)Robert Hooke
- b)Purkinje
- c)Leeuwenhoek
- d)Robert Brown
Correct answer is option 'C'. Can you explain this answer?
Living cells were discovered by
a)
Robert Hooke
b)
Purkinje
c)
Leeuwenhoek
d)
Robert Brown
|
Anita Menon answered |
Robert Hooke, a scientist, was the first person to discover the existence of cells with the help of a microscope in 1665 but they were dead cells.
Anton van Leeuwenhoek, in 1674 with the improved microscope, discovered free-living cells of algae Spirogyra in pond water for the first time.
The combining capacity of an element is called - a)Valency
- b)Atomicity
- c)Atomic number
- d)Valence electron
Correct answer is option 'A'. Can you explain this answer?
The combining capacity of an element is called
a)
Valency
b)
Atomicity
c)
Atomic number
d)
Valence electron
|
|
Aditi Sharma answered |
- The combining capacity of an element is known as its valency.
- Valency is the number of valence electrons in outer shell that take part in the chemical reaction.
Which of the following is not a mixture? a) Soap solutionb) Bloodc) Carbon dioxided) CoalCorrect answer is option 'C'. Can you explain this answer?
|
Gaurav Kumar answered |
Carbon dioxide is not a mixture since it contain fixed ratio of oxygen and carbon in 2:1, which is a property of compound not a mixture.
A desert is ...................- a)an endless stretch of sand
- b)without rainfall
- c)without vegetation
- d)all of the above
Correct answer is option 'D'. Can you explain this answer?
A desert is ...................
a)
an endless stretch of sand
b)
without rainfall
c)
without vegetation
d)
all of the above
|
Parth Nambiar answered |
Desert
Desert is a geographical region that is characterized by extreme dryness and lack of precipitation. It is a vast expanse of land that receives very little rainfall, and as a result, vegetation is scarce, and sand is abundant.
Endless stretch of sand
Deserts are often associated with endless stretches of sand dunes, but this is not always the case. While sand dunes are a common feature of many deserts, there are also rocky deserts, and deserts that are characterized by vast plains of gravel and dirt.
Without rainfall
Deserts are defined by their lack of rainfall, with many receiving less than 10 inches of rain per year. This lack of rainfall is often due to their location, such as being situated in areas that are far from oceans or other moisture sources.
Without vegetation
The extreme dryness of deserts means that vegetation is scarce, with many deserts being home to only a few types of plants that are adapted to the harsh desert environment. These plants often have specialized adaptations to help them survive in the arid conditions, such as the ability to store water in their leaves or roots.
All of the above
In conclusion, deserts are characterized by their lack of rainfall, scarcity of vegetation, and often vast stretches of sand or rocky terrain. These features make deserts some of the most inhospitable places on Earth, but they are also home to a variety of unique and fascinating plant and animal species that have adapted to the harsh desert environment.
Desert is a geographical region that is characterized by extreme dryness and lack of precipitation. It is a vast expanse of land that receives very little rainfall, and as a result, vegetation is scarce, and sand is abundant.
Endless stretch of sand
Deserts are often associated with endless stretches of sand dunes, but this is not always the case. While sand dunes are a common feature of many deserts, there are also rocky deserts, and deserts that are characterized by vast plains of gravel and dirt.
Without rainfall
Deserts are defined by their lack of rainfall, with many receiving less than 10 inches of rain per year. This lack of rainfall is often due to their location, such as being situated in areas that are far from oceans or other moisture sources.
Without vegetation
The extreme dryness of deserts means that vegetation is scarce, with many deserts being home to only a few types of plants that are adapted to the harsh desert environment. These plants often have specialized adaptations to help them survive in the arid conditions, such as the ability to store water in their leaves or roots.
All of the above
In conclusion, deserts are characterized by their lack of rainfall, scarcity of vegetation, and often vast stretches of sand or rocky terrain. These features make deserts some of the most inhospitable places on Earth, but they are also home to a variety of unique and fascinating plant and animal species that have adapted to the harsh desert environment.
Identify the correct symbol of Gold. - a)Go
- b)Gd
- c)Ge
- d)Au
Correct answer is option 'D'. Can you explain this answer?
Identify the correct symbol of Gold.
a)
Go
b)
Gd
c)
Ge
d)
Au
|
|
Aditi Sharma answered |
The chemical symbol for gold is Au, taken from the Latin word for gold- Aurum. Its atomic number is 79.
The smell of hydrogen sulphide (H2S) gas- a)pleasant
- b)of rotten egg
- c)of burning sulphur
- d)None of these
Correct answer is option 'B'. Can you explain this answer?
The smell of hydrogen sulphide (H2S) gas
a)
pleasant
b)
of rotten egg
c)
of burning sulphur
d)
None of these
|
Pooja Shah answered |
Hydrogen sulfide is a flammable, colorless gas with a characteristic odour of rotten eggs. It is commonly known as hydrosulfuric acid, sewer gas, and stink damp. People can smell it at low levels.
The atom is indivisible, was proposed by- a)Einstein
- b)Lavoisier
- c)Dalton
- d)Proust
Correct answer is option 'C'. Can you explain this answer?
The atom is indivisible, was proposed by
a)
Einstein
b)
Lavoisier
c)
Dalton
d)
Proust
|
Deepnarayan Chauhan answered |
Yes john Dalton say this first but this was expect after because this is made up of electron protein and nuetron
A car is moving with uniform speed and covers 100m in 50 second find the speed.- a)2m/s
- b)8m/s
- c)4m/s
- d)1m/s
Correct answer is option 'A'. Can you explain this answer?
A car is moving with uniform speed and covers 100m in 50 second find the speed.
a)
2m/s
b)
8m/s
c)
4m/s
d)
1m/s
|
Naina Sharma answered |
SPEED = DISTANCE / TIME
DISTANCE = 100M
TIME = 50 SEC
THEN, SPEED =100M / 50 SEC
SPEED = 2 M / S
DISTANCE = 100M
TIME = 50 SEC
THEN, SPEED =100M / 50 SEC
SPEED = 2 M / S
The cell organelles (other than the nucleus) which contain DNA are- a)plastids and lysosomes
- b)mitochondria and Golgi apparatus
- c)Golgi apparatus and lysosomes
- d)plastids and mitochondria
Correct answer is option 'D'. Can you explain this answer?
The cell organelles (other than the nucleus) which contain DNA are
a)
plastids and lysosomes
b)
mitochondria and Golgi apparatus
c)
Golgi apparatus and lysosomes
d)
plastids and mitochondria
|
Mohit Rajpoot answered |
Both mitochondria and plastids possess their own genetic material and ribosomes .
The mitochondria DNA and plastid DNA possess genes which produce the proteins necessary for the functioning of mitochondria and plastids respectively.
On a velocity-time graph, a horizontal straight line corresponds to motion at- a)constant velocity
- b)zero velocity
- c)increasing velocity
- d)decreasing velocity
Correct answer is option 'A'. Can you explain this answer?
On a velocity-time graph, a horizontal straight line corresponds to motion at
a)
constant velocity
b)
zero velocity
c)
increasing velocity
d)
decreasing velocity
|
|
Arun Sharma answered |
It is horizontal so, angle is zero and also acceleration is zero. Hence constant velocity.
If a plant cell is kept in a hypotonic solution, it will
- a)Increase in its volume
- b)Maintain the same volume
- c)Decrease in its volume
- d)Burst
Correct answer is option 'A'. Can you explain this answer?
If a plant cell is kept in a hypotonic solution, it will
a)
Increase in its volume
b)
Maintain the same volume
c)
Decrease in its volume
d)
Burst
|
Hansa Sharma answered |
When the plant cell is placed in a hypotonic solution , it takes up water by osmosis and starts to swell, but the cell wall prevents it from bursting.
If isotopic distribution of C-12 and C-14 are 98% and 2% respectively, then number of C-14 atoms in 12 g of carbon is
- a)1.032 x 1022
- b)6.886 × 1023
- c)3.88 x 1022
- d)1.302 x 1022
Correct answer is option 'A'. Can you explain this answer?
If isotopic distribution of C-12 and C-14 are 98% and 2% respectively, then number of C-14 atoms in 12 g of carbon is
a)
1.032 x 1022
b)
6.886 × 1023
c)
3.88 x 1022
d)
1.302 x 1022
|
|
Ananya Das answered |
In 12 g of carbon, the amount of C-14
= 12 × 2/100 = 0⋅24g
∴ C-14 atoms in 0.24g = (0⋅24×6⋅02×1023)/14
= 1⋅03×1022 atoms.
= 12 × 2/100 = 0⋅24g
∴ C-14 atoms in 0.24g = (0⋅24×6⋅02×1023)/14
= 1⋅03×1022 atoms.
Na+ has 12 neutrons and 10 electrons. Which of the following statement is correct?
- a)Na+ has atomic number equal to 10 and mass number 22
- b)Na+ has atomic number equal to 11 and mass number 23
- c)Na+ has atomic number equal to 10 and mass number 23
- d)Na+ has atomic number equal to 11 and mass number 22
Correct answer is option 'B'. Can you explain this answer?
Na+ has 12 neutrons and 10 electrons. Which of the following statement is correct?
a)
Na+ has atomic number equal to 10 and mass number 22
b)
Na+ has atomic number equal to 11 and mass number 23
c)
Na+ has atomic number equal to 10 and mass number 23
d)
Na+ has atomic number equal to 11 and mass number 22
|
|
Geetika Shah answered |
The chemical symbol Na+ represents a sodium ion. The atomic number of sodium (Na) is 11, which means it has 11 protons.
Given that Na+ has 12 neutrons, we can determine the mass number by adding the number of neutrons to the number of protons. So, for Na+:
Given that Na+ has 12 neutrons, we can determine the mass number by adding the number of neutrons to the number of protons. So, for Na+:
Mass number = Number of neutrons + Number of protons Mass number = 12 neutrons + 11 protons Mass number = 23
The atomic number remains unchanged because it is determined by the number of protons, which is characteristic of each element. The loss or gain of electrons to form ions does not change the atomic number.
Therefore, the correct statement is: Na+ has an atomic number equal to 11 and a mass number of 23.
The magnitude of the displacement of an object is always- a)greater than the distance travelled
- b)equal to the distance travelled
- c)less than the distance travelled
- d)less than or equal to the distance travelled
Correct answer is option 'D'. Can you explain this answer?
The magnitude of the displacement of an object is always
a)
greater than the distance travelled
b)
equal to the distance travelled
c)
less than the distance travelled
d)
less than or equal to the distance travelled
|
|
Hansa Sharma answered |
- Displacement is the shortest straight line distance between the initial and final position. This means that there doesn't exist any other path which is shorter than it.
- If the object travels with that shortest straight-line path then the magnitude of distance and displacement would be the same.
- If the object doesn't do so and travels with any other paths then as the other path is not the shortest path, so it will be larger than that of displacement. So if the object travels with this path then the magnitude of displacement will be smaller than the distance.
Thus, the magnitude of displacement may be equal to or smaller than that of distance.
Which one of the following phrases would be incorrect to use?- a)A mole of an element
- b)A mole of a compound
- c)An atom of an element
- d)An atom of a compound
Correct answer is option 'D'. Can you explain this answer?
Which one of the following phrases would be incorrect to use?
a)
A mole of an element
b)
A mole of a compound
c)
An atom of an element
d)
An atom of a compound
|
|
Krishna Iyer answered |
it will be incorrect to say that an atom of a compound because,
Every combination of atoms is a molecule. A compound is a molecule made of atoms from different elements. All compounds are molecules , but not all molecules are compounds.
Every combination of atoms is a molecule. A compound is a molecule made of atoms from different elements. All compounds are molecules , but not all molecules are compounds.
An external influence which changes or tends to change the state of rest or uniform motion of body or its dimensions is called:- a)momentum
- b)force
- c)moment of force
- d)pressure
Correct answer is 'B'. Can you explain this answer?
An external influence which changes or tends to change the state of rest or uniform motion of body or its dimensions is called:
a)
momentum
b)
force
c)
moment of force
d)
pressure
|
|
Ananya Das answered |
The slope of the velocity-time graph determines the acceleration.
The proteins and lipids, essential for building the cell membrane, are manufactured by- a)rough endoplasmic reticulum
- b)Golgi apparatus
- c)plasma membrane
- d)mitochondria
Correct answer is option 'A'. Can you explain this answer?
The proteins and lipids, essential for building the cell membrane, are manufactured by
a)
rough endoplasmic reticulum
b)
Golgi apparatus
c)
plasma membrane
d)
mitochondria
|
Keshav Kapoor answered |
Yes because ribosomes are sites are protein manufacture and they are found attached to the rough ER
Following are a few definitions of osmosis. Read carefully and select the correct definition. - a)Movement of water molecules from a region of higher concentration to a region of lower concentration through a semipermeable membrane
- b)Movement of solvent molecules from its higher concentration to lower concentration
- c)Movement of solvent molecules from higher concentration to lower concentration of solution through a permeable membrane
- d)Movement of solute molecules from lower concentration to higher concentration of solution through a semipermeable membrane
Correct answer is option 'A'. Can you explain this answer?
Following are a few definitions of osmosis. Read carefully and select the correct definition.
a)
Movement of water molecules from a region of higher concentration to a region of lower concentration through a semipermeable membrane
b)
Movement of solvent molecules from its higher concentration to lower concentration
c)
Movement of solvent molecules from higher concentration to lower concentration of solution through a permeable membrane
d)
Movement of solute molecules from lower concentration to higher concentration of solution through a semipermeable membrane
|
Raghav Bansal answered |
Osmosis is the passive movement of water or any other solvent molecules from a region of higher water concentration to a region of lower water concentration through a semipermeable membrane. This brings both the solutions separated by the semipermeable membrane to the equilibrium. Therefore, option A is correct.
A prokaryotic cell does not possess- a)cell membrane
- b)cell wall
- c)nuclear membrane
- d)both (a) and (c)
Correct answer is option 'C'. Can you explain this answer?
A prokaryotic cell does not possess
a)
cell membrane
b)
cell wall
c)
nuclear membrane
d)
both (a) and (c)
|
|
Moonlight Stargirl answered |
Prokaryotic cells have no nuclear membrane thus there nucleus is considered not well defined
Which of the following is the chemical symbol for nitrogen gas?
- a)N2
- b)N
- c)N3
- d)Ni
Correct answer is option 'A'. Can you explain this answer?
Which of the following is the chemical symbol for nitrogen gas?
a)
N2
b)
N
c)
N3
d)
Ni
|
Mahi Chauhan answered |
The chemical formula of Nitrogen is N but Nitrogen exists in the molecule of two ions hence the chemical symbol of Nitrogen gas is written as N2.
1.0 mole CO2 contains- a)6.022 x 10-23 atoms of carbon
- b)6.022 X 10-23 atoms of oxygen
- c)6.022 x 1023 molecules of CO2
- d)3g atom of CO2
Correct answer is option 'C'. Can you explain this answer?
1.0 mole CO2 contains
a)
6.022 x 10-23 atoms of carbon
b)
6.022 X 10-23 atoms of oxygen
c)
6.022 x 1023 molecules of CO2
d)
3g atom of CO2
|
Swati Verma answered |
- One mole of CO2 = one mole of C = 6.02×10 23 atoms of carbon.
- One mole of CO2 = two moles of O = 2×6.02×1023= 12.04×10 23 atoms of oxygen.
- One mole of CO2 = 6.02×1023 molecules of CO2
Note: 6.02×1023 is Avogadro's number and represents number of atoms/molecules present in one mole of substance.
Identify the correct one from the following statements. - a)Elements can be changed into simpler substances.
- b)Compound has variable composition
- c)The mixture has properties similar to its components.
- d)Brass is a compound of Copper and Zinc
Correct answer is option 'C'. Can you explain this answer?
Identify the correct one from the following statements.
a)
Elements can be changed into simpler substances.
b)
Compound has variable composition
c)
The mixture has properties similar to its components.
d)
Brass is a compound of Copper and Zinc
|
|
Geetika Shah answered |
option ( c) The mixture has properties similar to its compound is the correct answer.
Explanation:-
This is because in a mixture, the constituent particles are not mixed chemically.
They are mixed physically and can be separated fairly easily by physical Methods.
Thus they show the properties of components.
Example can be alloys.
They are mixed physically and can be separated fairly easily by physical Methods.
Thus they show the properties of components.
Example can be alloys.
Which of the following is not correct?
- a)SI unit of temperature is kelvin
- b)SI unit of pressure is Newton
- c)SI unit of density is kg/m3
- d)1 litre = 1000 cm3 - 1 dm3
Correct answer is option 'B'. Can you explain this answer?
Which of the following is not correct?
a)
SI unit of temperature is kelvin
b)
SI unit of pressure is Newton
c)
SI unit of density is kg/m3
d)
1 litre = 1000 cm3 - 1 dm3
|
|
Kritika Bose answered |
SI Units of Measurement
SI units are the International System of Units, which is the modern form of the metric system. It is used in scientific and technical fields as a standard system of measurement. The SI system has seven base units, which are used to derive all other units of measurement.
SI Units of Temperature, Pressure, Density and Volume
Temperature: The SI unit of temperature is Kelvin (K), not Celsius (°C).
Pressure: The SI unit of pressure is Pascal (Pa), not atm (atmosphere).
Density: The SI unit of density is kilograms per cubic meter (kg/m3).
Volume: The SI unit of volume is cubic meter (m3). However, liter (L) is also commonly used as a non-SI unit of volume. 1 L = 1000 cm3 = 1 dm3.
Conclusion
Option B is not correct because the SI unit of pressure is Pascal (Pa), not atm (atmosphere). Atm is a non-SI unit of pressure. Therefore, the correct answer is option B.
SI units are the International System of Units, which is the modern form of the metric system. It is used in scientific and technical fields as a standard system of measurement. The SI system has seven base units, which are used to derive all other units of measurement.
SI Units of Temperature, Pressure, Density and Volume
Temperature: The SI unit of temperature is Kelvin (K), not Celsius (°C).
Pressure: The SI unit of pressure is Pascal (Pa), not atm (atmosphere).
Density: The SI unit of density is kilograms per cubic meter (kg/m3).
Volume: The SI unit of volume is cubic meter (m3). However, liter (L) is also commonly used as a non-SI unit of volume. 1 L = 1000 cm3 = 1 dm3.
Conclusion
Option B is not correct because the SI unit of pressure is Pascal (Pa), not atm (atmosphere). Atm is a non-SI unit of pressure. Therefore, the correct answer is option B.
Which of the following statements is incorrect?
- a)Matter is made up of particles
- b)Particles of matter are always in state of motion
- c)Matter is continuous in nature
- d)Particles of matter attract each other
Correct answer is option 'C'. Can you explain this answer?
Which of the following statements is incorrect?
a)
Matter is made up of particles
b)
Particles of matter are always in state of motion
c)
Matter is continuous in nature
d)
Particles of matter attract each other
|
Bhaskar Chatterjee answered |
Incorrect Statement: Matter is continuous in nature.
Explanation:
Matter is made up of small particles called atoms and molecules that have mass and occupy space. These particles are not continuous but are separated by empty spaces. Therefore, the statement that "matter is continuous in nature" is incorrect.
Evidence Supporting the Correct Statements:
a) Matter is made up of particles:
The concept of matter being made up of small particles was first proposed by the Greek philosopher Democritus in the 5th century BC. This idea was later supported by scientists like John Dalton, who proposed the atomic theory of matter in the 19th century. Today, we know that matter is made up of atoms and molecules.
b) Particles of matter are always in a state of motion:
Particles of matter are always in motion, even when they appear to be at rest. This motion can be either random or organized. The kinetic theory of matter explains that the temperature of matter is related to the speed of its particles. When matter is heated, the particles move faster and vice versa.
d) Particles of matter attract each other:
Particles of matter attract each other due to the presence of forces like gravitational, electric, and magnetic forces. These forces allow particles to stick together and form larger structures like molecules, crystals, and even planets.
Conclusion:
In conclusion, the statement that "matter is continuous in nature" is incorrect. Matter is made up of small particles that are separated by empty spaces. These particles are always in motion and attract each other due to the presence of forces.
Explanation:
Matter is made up of small particles called atoms and molecules that have mass and occupy space. These particles are not continuous but are separated by empty spaces. Therefore, the statement that "matter is continuous in nature" is incorrect.
Evidence Supporting the Correct Statements:
a) Matter is made up of particles:
The concept of matter being made up of small particles was first proposed by the Greek philosopher Democritus in the 5th century BC. This idea was later supported by scientists like John Dalton, who proposed the atomic theory of matter in the 19th century. Today, we know that matter is made up of atoms and molecules.
b) Particles of matter are always in a state of motion:
Particles of matter are always in motion, even when they appear to be at rest. This motion can be either random or organized. The kinetic theory of matter explains that the temperature of matter is related to the speed of its particles. When matter is heated, the particles move faster and vice versa.
d) Particles of matter attract each other:
Particles of matter attract each other due to the presence of forces like gravitational, electric, and magnetic forces. These forces allow particles to stick together and form larger structures like molecules, crystals, and even planets.
Conclusion:
In conclusion, the statement that "matter is continuous in nature" is incorrect. Matter is made up of small particles that are separated by empty spaces. These particles are always in motion and attract each other due to the presence of forces.
Which of the following symbols is incorrect?
(i) Helium (He)
(ii) Aluminium (AL)
(iii) Carbon (c)
(iv) Cobalt (CO)
Select the correct alternative:
- a)(i) and (ii)
- b)(i), (ii) and (iii)
- c)(ii), (iii) and (iv)
- d)(i), (iii) and (iv)
Correct answer is option 'C'. Can you explain this answer?
Which of the following symbols is incorrect?
(i) Helium (He)
(ii) Aluminium (AL)
(iii) Carbon (c)
(iv) Cobalt (CO)
Select the correct alternative:
(i) Helium (He)
(ii) Aluminium (AL)
(iii) Carbon (c)
(iv) Cobalt (CO)
Select the correct alternative:
a)
(i) and (ii)
b)
(i), (ii) and (iii)
c)
(ii), (iii) and (iv)
d)
(i), (iii) and (iv)
|
|
Ananya Das answered |
Because , the symbol used for aluminum is Al, the symbol used for carbon is C, the symbol used for cobalt is Co.
A cell will swell up if- a)the concentration of water molecules in the cell is higher than the concentration of water molecules in surrounding medium
- b)the concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell
- c)the concentration of water molecules is same in the cell and in the surrounding medium
- d)concentration of water molecules does not matter
Correct answer is option 'B'. Can you explain this answer?
A cell will swell up if
a)
the concentration of water molecules in the cell is higher than the concentration of water molecules in surrounding medium
b)
the concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell
c)
the concentration of water molecules is same in the cell and in the surrounding medium
d)
concentration of water molecules does not matter
|
|
Madhu answered |
Option b
Find the average speed of a bicycle if it completes two round of a circular track of radius 140m twice in 5min 52 sec.- a)10m/s
- b)5m/s
- c)2m/s
- d)4m/s
Correct answer is option 'B'. Can you explain this answer?
Find the average speed of a bicycle if it completes two round of a circular track of radius 140m twice in 5min 52 sec.
a)
10m/s
b)
5m/s
c)
2m/s
d)
4m/s
|
|
Rohit Sharma answered |
Radius of truck = r = 140m
circumfarance
Time taken to cover the distance = t = 5 min 52 sec = 352 sec
Since it complete 2 rounds, therefor distance it travels is 2 times of circumference.
circumfarance
Time taken to cover the distance = t = 5 min 52 sec = 352 sec
Since it complete 2 rounds, therefor distance it travels is 2 times of circumference.
The only cell organelle present in prokaryotic cell is - a)mitochondria
- b)ribosome
- c)plastids
- d)lysosome
Correct answer is option 'B'. Can you explain this answer?
The only cell organelle present in prokaryotic cell is
a)
mitochondria
b)
ribosome
c)
plastids
d)
lysosome
|
Lokesh Kumar answered |
Ribosomes are a cell structure that makes protein. Protein is needed for many cell functions such as repairing damage or directing chemical processes. Ribosomes can be found floating within the cytoplasm or attached to the endoplasmic reticulum.
Find out the correct sentence. - a)Enzymes packed in lysosomes are made through RER
- b)Rough endoplasmic reticulum and smooth endoplasmic reticulum produce lipid and protein respectively
- c)Endoplasmic reticulum is related to the destruction of plasma membrane
- d)Nucleoid is present inside the nucleoplasm of eukaryotic nucleus
Correct answer is option 'A'. Can you explain this answer?
Find out the correct sentence.
a)
Enzymes packed in lysosomes are made through RER
b)
Rough endoplasmic reticulum and smooth endoplasmic reticulum produce lipid and protein respectively
c)
Endoplasmic reticulum is related to the destruction of plasma membrane
d)
Nucleoid is present inside the nucleoplasm of eukaryotic nucleus
|
|
Ananya Das answered |
Option B: Rough endoplasmic reticulum produce proteins and smooth endoplasmic reticulum produce lipids. Hence, given statement is wrong.
Option C: Endoplasmic reticulum is related with the making of plasma membrane. It makes the proteins (with the help of ribosomes) and lipids which are used for membrane synthesis. Hence, given statement is false.
Option D: Nuclear material of a prokaryotic cell consists of a single chromosome which is not membrane bound and lies naked in cytoplasm. Such, nuclear region of cytoplasm is called as nucleoid. Hence, given statement is wrong.
Option A: Lysosomal enzymes are made by rough endoplasmic reticulum. The ribosomes present on rough endoplasmic reticulum are involved in protein synthesis. Almost all enzymes are proteins
So, the correct answer is 'Enzymes packed in lysosomes are made through RER (rough endoplasmic reticulum)'
Equations of motion can be used for a body having- a)uniform motion
- b)non-uniform motion
- c)uniform acceleration
- d)non-uniform acceleration
Correct answer is option 'C'. Can you explain this answer?
Equations of motion can be used for a body having
a)
uniform motion
b)
non-uniform motion
c)
uniform acceleration
d)
non-uniform acceleration
|
|
Ananya Das answered |
The equations of motion are applicable only when the body moves with uniform acceleration. A body under constant acceleration is uniformly accelerated motion.
The process of separation of insoluble solids from a liquid is called:- a)Filtration
- b)Decantation
- c)Crystallisation
- d)Evaporation
Correct answer is option 'A'. Can you explain this answer?
The process of separation of insoluble solids from a liquid is called:
a)
Filtration
b)
Decantation
c)
Crystallisation
d)
Evaporation
|
|
Krishna Iyer answered |
Filtration is a method for separating an insoluble solid from a liquid. When a mixture of sand and water is filtered: the sand stays behind in the filter paper (it becomes the residue ) the water passes through the filter paper (it becomes the filtrate).
70-80 % of volume of a mature plant cell is occupied by- a)endoplasmic reticulum
- b)nucleus
- c)cytoplasm
- d)vacuole
Correct answer is option 'D'. Can you explain this answer?
70-80 % of volume of a mature plant cell is occupied by
a)
endoplasmic reticulum
b)
nucleus
c)
cytoplasm
d)
vacuole
|
|
Naina Sharma answered |
The mature cell has simple tissues rather than meristematic tissues so they will not divide and plant cell needs vacuole to make itself rigid and various excretion and storage works are also done by the vacuoles.
So, the vacuoles perform majority of the tasks of the plant cell and hence this is the reason, a mature plant cell has 70-80% of vacuoles in them.
Engulfing of food materials or foreign bodies by cells like Amoeba is called- a)diffusion
- b)endocytosis
- c)osmosis
- d)plasmolysis
Correct answer is option 'B'. Can you explain this answer?
Engulfing of food materials or foreign bodies by cells like Amoeba is called
a)
diffusion
b)
endocytosis
c)
osmosis
d)
plasmolysis
|
|
Arun Sharma answered |
Organisms like Amoeba have flexible cell membrane due to which they can take in food material or engulf foreign bodies through the process called endocytosis.
Can you explain the answer of this question below:What is the quantity which is measured as the area occupied in the velocity – time graph?
- A:
distance
- B:
displacement distance speed acceleration
- C:
acceleration
- D:
speed
The answer is B.
What is the quantity which is measured as the area occupied in the velocity – time graph?
distance
displacement distance speed acceleration
acceleration
speed
|
Vikram Khanna answered |
The area under the velocity time graph will give us the displacement of an object and the slope gives the acceleration we should find the area under the graph , if the graph is irregular we need to split it into parts and finally add them and if the shape is not at all regular we should go for integration.
Which one of the following sets of phenomenon would increase on raising the temperature?- a)Evaporation, diffusion, compression of gases
- b)Evaporation, compression of gases, solubility
- c)Evaporation, diffusion, expansion of gases
- d)Evaporation, solubility, diffusion, compression of gases.
Correct answer is option 'C'. Can you explain this answer?
Which one of the following sets of phenomenon would increase on raising the temperature?
a)
Evaporation, diffusion, compression of gases
b)
Evaporation, compression of gases, solubility
c)
Evaporation, diffusion, expansion of gases
d)
Evaporation, solubility, diffusion, compression of gases.
|
Mihir Shah answered |
The correct answer is option 'C': Evaporation, diffusion, expansion of gases.
Explanation:
When the temperature is increased, several physical processes tend to increase. These processes include evaporation, diffusion, and expansion of gases. Let's understand each of these phenomena in detail:
1. Evaporation:
Evaporation is the process by which a liquid changes into a vapor or gas at temperatures below its boiling point. When the temperature is increased, the kinetic energy of the molecules in the liquid also increases. As a result, more molecules gain enough energy to overcome the attractive forces of the liquid and escape into the gas phase. Therefore, evaporation increases with an increase in temperature.
2. Diffusion:
Diffusion is the process of movement of particles from an area of higher concentration to an area of lower concentration. It occurs due to the random motion of particles. When the temperature is increased, the kinetic energy of the particles also increases. This increased kinetic energy leads to faster and more frequent collisions between particles, resulting in an increased rate of diffusion.
3. Expansion of gases:
When gases are heated, their molecules gain kinetic energy and move faster. This increased molecular motion leads to an increase in the volume of the gas because the molecules now occupy a larger space. Therefore, gases expand when the temperature is raised.
These three phenomena - evaporation, diffusion, and expansion of gases - all increase with an increase in temperature.
Let's summarize the answer:
- Evaporation, the process by which a liquid changes into a vapor or gas, increases with an increase in temperature.
- Diffusion, the movement of particles from an area of higher concentration to an area of lower concentration, increases with an increase in temperature.
- Expansion of gases occurs when the temperature is raised, as the increased kinetic energy of the gas molecules causes them to move faster and occupy a larger volume.
Hence, the correct answer is option 'C': Evaporation, diffusion, expansion of gases.
Explanation:
When the temperature is increased, several physical processes tend to increase. These processes include evaporation, diffusion, and expansion of gases. Let's understand each of these phenomena in detail:
1. Evaporation:
Evaporation is the process by which a liquid changes into a vapor or gas at temperatures below its boiling point. When the temperature is increased, the kinetic energy of the molecules in the liquid also increases. As a result, more molecules gain enough energy to overcome the attractive forces of the liquid and escape into the gas phase. Therefore, evaporation increases with an increase in temperature.
2. Diffusion:
Diffusion is the process of movement of particles from an area of higher concentration to an area of lower concentration. It occurs due to the random motion of particles. When the temperature is increased, the kinetic energy of the particles also increases. This increased kinetic energy leads to faster and more frequent collisions between particles, resulting in an increased rate of diffusion.
3. Expansion of gases:
When gases are heated, their molecules gain kinetic energy and move faster. This increased molecular motion leads to an increase in the volume of the gas because the molecules now occupy a larger space. Therefore, gases expand when the temperature is raised.
These three phenomena - evaporation, diffusion, and expansion of gases - all increase with an increase in temperature.
Let's summarize the answer:
- Evaporation, the process by which a liquid changes into a vapor or gas, increases with an increase in temperature.
- Diffusion, the movement of particles from an area of higher concentration to an area of lower concentration, increases with an increase in temperature.
- Expansion of gases occurs when the temperature is raised, as the increased kinetic energy of the gas molecules causes them to move faster and occupy a larger volume.
Hence, the correct answer is option 'C': Evaporation, diffusion, expansion of gases.
The only cell organelle seen in prokaryotic cell is - a)mitochondria
- b)ribosomes
- c)plastids
- d)lysosomes
Correct answer is option 'B'. Can you explain this answer?
The only cell organelle seen in prokaryotic cell is
a)
mitochondria
b)
ribosomes
c)
plastids
d)
lysosomes
|
|
Aradhiya Gupta answered |
Ribosome because it is membraneless organelles and also prokaryoted are those having not nuclear membrane
The percentage of hydrogen in water is______.
- a)1.11%
- b)11.11%
- c)8.89 %
- d)88.9%
Correct answer is option 'B'. Can you explain this answer?
The percentage of hydrogen in water is______.
a)
1.11%
b)
11.11%
c)
8.89 %
d)
88.9%
|
|
Arun Sharma answered |
There is also one mole of oxygen atoms weighing 16.00 grams in the mole of water and that of hydrogen is 2.00 gram.
To get the percentage of hydrogen, divide the 2 by 18 and multiply by 100.
i.e. Percentage of hydrogen = (2/18) x 100 = 11.11%
To get the percentage of hydrogen, divide the 2 by 18 and multiply by 100.
i.e. Percentage of hydrogen = (2/18) x 100 = 11.11%
Solids do not flow because - a)of large molecular space between particles
- b)they do not have definite shape
- c)they have very strong intermolecular forces in between particles
- d)all of these
Correct answer is option 'C'. Can you explain this answer?
Solids do not flow because
a)
of large molecular space between particles
b)
they do not have definite shape
c)
they have very strong intermolecular forces in between particles
d)
all of these
|
Moumita Mishra answered |
Any thing flows due to weaker intermolecular forces between them.
18 g of water is electrolysed. The weight of oxygen formed will be - a)16 g
- b)8 g
- c)4 g
- d)2 g
Correct answer is option 'A'. Can you explain this answer?
18 g of water is electrolysed. The weight of oxygen formed will be
a)
16 g
b)
8 g
c)
4 g
d)
2 g
|
|
Parth Khanna answered |
Electrolysis of Water
Electrolysis is a process of decomposition of a compound by passing electricity through it. Water can also be electrolyzed to produce hydrogen and oxygen gases.
The balanced chemical equation for the electrolysis of water is as follows:
2H2O(l) → 2H2(g) + O2(g)
From this equation, it is clear that for every 2 moles of water electrolyzed, 1 mole of oxygen gas is produced.
Calculation of Oxygen Gas Produced
Given that 18 g of water is electrolyzed, we need to calculate the weight of oxygen gas produced.
The molar mass of water (H2O) is 18 g/mol. Therefore, 18 g of water is equal to 1 mole of water.
According to the balanced chemical equation, 1 mole of water produces 1/2 mole of oxygen gas.
The molar mass of oxygen (O2) is 32 g/mol. Therefore, 1/2 mole of oxygen gas is equal to 16 g.
Hence, the weight of oxygen gas produced from the electrolysis of 18 g of water is 16 g.
Therefore, option A, 16 g, is the correct answer.
Electrolysis is a process of decomposition of a compound by passing electricity through it. Water can also be electrolyzed to produce hydrogen and oxygen gases.
The balanced chemical equation for the electrolysis of water is as follows:
2H2O(l) → 2H2(g) + O2(g)
From this equation, it is clear that for every 2 moles of water electrolyzed, 1 mole of oxygen gas is produced.
Calculation of Oxygen Gas Produced
Given that 18 g of water is electrolyzed, we need to calculate the weight of oxygen gas produced.
The molar mass of water (H2O) is 18 g/mol. Therefore, 18 g of water is equal to 1 mole of water.
According to the balanced chemical equation, 1 mole of water produces 1/2 mole of oxygen gas.
The molar mass of oxygen (O2) is 32 g/mol. Therefore, 1/2 mole of oxygen gas is equal to 16 g.
Hence, the weight of oxygen gas produced from the electrolysis of 18 g of water is 16 g.
Therefore, option A, 16 g, is the correct answer.
Which of the following graphs show that the body is at rest?- a)
- b)
- c)
- d)
Correct answer is option 'A'. Can you explain this answer?
Which of the following graphs show that the body is at rest?
a)
b)
c)
d)
|
Ishan Choudhury answered |
In figure A, we can see that the object continues to remain at a fixed place while the time keeps running. So, the object is at rest, because the object does not change its position with time.
Fat is abundant in- a)Liver cells
- b)Alveolar tissue
- c)Lymph glands
- d)Adipose tissue
Correct answer is option 'D'. Can you explain this answer?
Fat is abundant in
a)
Liver cells
b)
Alveolar tissue
c)
Lymph glands
d)
Adipose tissue
|
|
Vikram Verma answered |
D is the correct option.The fat stored in adipose tissue comes from dietary fats or is produced in the body. hormone signaling; adipose tissueWhen hormones signal the need for energy, fatty acids and glycerol are released from triglycerides stored in fat cells (adipocytes) and are delivered to organs and tissues in the body.
Striated muscles are found in- a)Gall bladder
- b)Wall of bronchi
- c)Skeletal muscles
- d)Lungs
Correct answer is option 'C'. Can you explain this answer?
Striated muscles are found in
a)
Gall bladder
b)
Wall of bronchi
c)
Skeletal muscles
d)
Lungs
|
Ananya Sharma answered |
Skeletal muscle is one of three major muscle types, the others being cardiac muscle and smooth muscle. It is a form of striated muscle tissue which is under the voluntary control of the somatic nervous system. Most skeletal muscles are attached to bones by bundles of collagen fibers known as tendons.
Match the following with correct response. 
- a)1-C, 2-B, 3-D, 4-A
- b)1-A, 2-C, 3-B, 4-D
- c)1-D, 2-A, 3-C, 4-B
- d)1-B, 2-D, 3-A, 4-C
Correct answer is option 'C'. Can you explain this answer?
Match the following with correct response.
a)
1-C, 2-B, 3-D, 4-A
b)
1-A, 2-C, 3-B, 4-D
c)
1-D, 2-A, 3-C, 4-B
d)
1-B, 2-D, 3-A, 4-C
|
|
Pooja Shah answered |
Mixtures are one product of mechanically blending or mixing chemical substances such as elements and compounds, without chemical bonding or other chemical change, so that each ingredient substance retains its own chemical properties and makeup.
A chemical compound is a substance composed of two or more different elements chemically bonded together in a fixed proportion by mass. However, not all molecules are compounds. Compounds are pure substances that contain two or more elements combined in a definite fixed proportion.
Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions.
When a molecule is formed from elements of a different species it is a heteroatomic molecule. As an atom is the smallest particle of an element that retains the properties of that element, a molecule is the smallest particle of a compound.
A chemical compound is a substance composed of two or more different elements chemically bonded together in a fixed proportion by mass. However, not all molecules are compounds. Compounds are pure substances that contain two or more elements combined in a definite fixed proportion.
Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions.
When a molecule is formed from elements of a different species it is a heteroatomic molecule. As an atom is the smallest particle of an element that retains the properties of that element, a molecule is the smallest particle of a compound.
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