important mcq biology

Question 1

To remove chlorophyll, the leaf should be boiled in _______.

A.Water

B.Alcohol

C. Iodine solution

D. Potassium permanganate

Correct Answer Alcohol

 Solution

Chlorophyll is the green pigment found in the leaves. It helps in the process of photosynthesis for preparing starch. For removing this pigment from the leaves, alcohol (ethanol) is used. 

The process is as follows:

1. Heat a leaf in boiling water for 30 seconds. This will kill the leaf and stop any chemical reaction.
2. Now add the blanched leaf to the boiling ethanol in a water bath for a few minutes. 
3. The boiling ethanol dissolves the chlorophyll and removes the green colour from the leaf. 
4. The leaf turns white, and hence, the change in colour can be observed now.

So, the correct answer is option B.

Question 2 

Pseudopodia in amoeba helps in:

A.Locomotion

B.Engulfment

C.Ingestion

D.All of the above

Correct Answer All of the above

SOLUTION

• Pseudopodia is a temporary cytoplasm-filled projection of a eukaryotic cell membrane or a unicellular protist.
• Pseudopods may be used for motility, or for ingesting nutrients or other particulate matter. It senses the prey that can then be engulfed; the engulfing pseudopodia are called phagocytosis pseudopodia. Hence, pseudopodia in amoeba help in locomotion, engulfment, and ingestion.
  

So, the correct answer is 'all of the above.

3

Lymph contains ........... proteins than plasma.

A.

Less

B.

More

Your Answer

C.

Equal

D.

None of the above

Blood is not a tissue because it is a fluid.

A

True

B

False

Your Answer

SOLUTION

Blood is considered a connective tissue due to two basic reasons: 

(1) Embryologically, it has the same origin (mesodermal) as other connective tissues. 

(2) Blood connects the body systems together and transports the required oxygen, nutrients, hormones, and other signaling molecules, and removes the wastes. 
So, the correct answer is option B.

Blood is not a tissue because it is a fluid.

A

True

B

False

Your Answer

SOLUTION

Blood is considered a connective tissue due to two basic reasons: 

(1) Embryologically, it has the same origin (mesodermal) as other connective tissues. 

(2) Blood connects the body systems together and transports the required oxygen, nutrients, hormones, and other signaling molecules, and removes the wastes. 
So, the correct answer is option B.

05

Excretion means:

A.

Removal of harmful metabolic wastes from the body

Your Answer

B.

Formation of the metabolic substances which plays some role in the body

C.

Breakdown of large insoluble food molecules into small water-soluble food molecules

D.

Formation of new offspring by an individual organism

SOLUTION

Excretion is an essential process in all forms of life.

It is a process in which metabolic waste is eliminated from the body of an organism. Accumulation of these wastes beyond a level inside the body is harmful to the body of an organism.

In mammals, urine is expelled with the help of the excretory system. In unicellular organisms, waste products are discharged directly through the surface of the cell.

In green plants, excretory gases like carbon dioxide and oxygen exit the plant body through stomata, root cell walls, etc. They also eliminate waste materials in the form of resin, saps, latex, etc.

So, the correct answer is option A.

06

Human body loses water by

A.

Sweating

B.

Excretion

C.

Breathing

Your Answer

D.

All of the above

Correct Answer

SOLUTION

The human body loses water primarily by excreting it in urine from the kidneys. A fair amount of water is lost daily when water evaporates from the skin in form of sweating and some of it is breathed out by the lungs. 

07

The autotrophic mode of nutrition requires

A.

Carbon dioxide

Your Answer

B.

Chlorophyll

C.

Sunlight

D.

All of the above

Correct Answer

SOLUTION

Autotrophic mode of nutrition requires carbon dioxide, chlorophyll and sunlight to produce the food in plants through photosynthesis.

Hence, option D- All of the above is correct.

08

Man is .......... in nutrition.

A.

Chemotrophic

B.

Phototrophic

C.

Heterotrophic

Your Answer

D.

Autotrophic

SOLUTION

A man, like all other members of kingdom Animalia, is heterotrophic and is dependent either directly or indirectly on plants for nutrition. Heterotrophic organisms cannot produce their own food and are dependent on autotrophs such as green plants for their nutritional requirements. 

So, the correct answer is option C - 'Heterotrophic'.

09

Respiration involving the use of oxygen to produce energy is called ________.

A.

Plant respiration

Your Answer

B.

Anaerobic respiration

C.

Animal respiration

D.

Aerobic respiration

Correct Answer

SOLUTION

Aerobic respiration is the process of producing cellular energy involving oxygen. After glycolysis, pyruvate from glucose, the three-carbon molecule of pyruvic acid gets further broken down to give three molecules of carbon dioxide and water. This process takes place in the mitochondria of a cell in the presence of oxygen and energy is released. Plants and animals both undergo this type of respiration.

Anaerobic respiration involves respiration without oxygen.

Therefore, the correct answer is option D.

10

Number of heart chambers present in human is 3

A

True

B

False

Your Answer

SOLUTION

The heart has four chambers: two atria and two ventricles. The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle, whereas the left atrium receives oxygenated blood from the lungs and the left ventricle pumps it to the whole body.

So, the correct option is 'False'.

Excretion means:

A.

Removal of harmful metabolic wastes from the body

Your Answer

B.

Formation of the metabolic substances which plays some role in the body

C.

Breakdown of large insoluble food molecules into small water-soluble food molecules

D.

Formation of new offspring by an individual organism

SOLUTION

Excretion is an essential process in all forms of life.

It is a process in which metabolic waste is eliminated from the body of an organism. Accumulation of these wastes beyond a level inside the body is harmful to the body of an organism.

In mammals, urine is expelled with the help of the excretory system. In unicellular organisms, waste products are discharged directly through the surface of the cell.

In green plants, excretory gases like carbon dioxide and oxygen exit the plant body through stomata, root cell walls, etc. They also eliminate waste materials in the form of resin, saps, latex, etc.

So, the correct answer is option A.

06

Human body loses water by

A.

Sweating

B.

Excretion

C.

Breathing

Your Answer

D.

All of the above

Correct Answer

SOLUTION

The human body loses water primarily by excreting it in urine from the kidneys. A fair amount of water is lost daily when water evaporates from the skin in form of sweating and some of it is breathed out by the lungs. 

07

The autotrophic mode of nutrition requires

A.

Carbon dioxide

Your Answer

B.

Chlorophyll

C.

Sunlight

D.

All of the above

Correct Answer

SOLUTION

Autotrophic mode of nutrition requires carbon dioxide, chlorophyll and sunlight to produce the food in plants through photosynthesis.

Hence, option D- All of the above is correct.

08

Man is .......... in nutrition.

A.

Chemotrophic

B.

Phototrophic

C.

Heterotrophic

Your Answer

D.

Autotrophic

SOLUTION

A man, like all other members of kingdom Animalia, is heterotrophic and is dependent either directly or indirectly on plants for nutrition. Heterotrophic organisms cannot produce their own food and are dependent on autotrophs such as green plants for their nutritional requirements. 

So, the correct answer is option C - 'Heterotrophic'.

09

Respiration involving the use of oxygen to produce energy is called ________.

A.

Plant respiration

Your Answer

B.

Anaerobic respiration

C.

Animal respiration

D.

Aerobic respiration

Correct Answer

SOLUTION

Aerobic respiration is the process of producing cellular energy involving oxygen. After glycolysis, pyruvate from glucose, the three-carbon molecule of pyruvic acid gets further broken down to give three molecules of carbon dioxide and water. This process takes place in the mitochondria of a cell in the presence of oxygen and energy is released. Plants and animals both undergo this type of respiration.

Anaerobic respiration involves respiration without oxygen.

Therefore, the correct answer is option D.

10

Number of heart chambers present in human is 3

A

True

B

False

SOLUTION

The heart has four chambers: two atria and two ventricles. The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle, whereas the left atrium receives oxygenated blood from the lungs and the left ventricle pumps it to the whole body.

So, the correct option is 'False'.