21.

National bird of India is

• Psittacula

• Passer domesticus

• Pavo cristatus

• Parakeet

Specific proteins responsible for the flow of materials and information into the cell are called

• membrane receptors

• carrier proteins

• integral proteins

• none of these

Assertion : Connective tissue inside the brain is essential for conduction of nerve impulse.

Reason : Connective tissue hold together the nerve cells of brain.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion: Cytokinins increases shelf life of fruits and vegetables.

Reason : Cytokinins induce cell division.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : Angina pectoris means "pain in the chest".

Reason : It results due to carrying of extra blood to the heart muscle.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : Glycolysis is the first step of respiration in which glucose completely breaks into CO₂ and H₂O.

Reason : In this process, there is net gain of twenty four molecules of ATP.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : Excess of nitrates in drinking water are harmful for infants.

Reason : Nitrates are responsible for blue baby syndrome.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : Nucleus is the controlling centre of a cell.

Reason : Pores in the nuclear envelop regulate the flow of materials in and out of the nucleus.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : Hormone calcitonin has antagonistic effect to that of parathormone.

Reason : Calcitonin decreases blood calcium level while parathormone increases blood calcium level.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : Dark reaction occurs only at night in the stroma of chloroplast.

Reason : CO₂ fixation occurs only during C₃ cycle.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false