Subject

Biology

Class

NEET Class 12

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

 Multiple Choice QuestionsMultiple Choice Questions

11.

Pick the correct group consisting of all genera exhibiting homospory

  • Lycopodium, Psilotum, Selaginella, Equisetum

  • Equisetum, Pteris, Salvinia, Psilotum

  • Salvinia, Pteris, Lycopodium, Selaginella

  • Equisetum, Psilotum, Lycopodium, Pteris


D.

Equisetum, Psilotum, Lycopodium, Pteris

Pteridophytes, may produce similar spores (homosporous) or dissimilar spores (heterosporous). Selaginella and Salvinia show heterospory.


12.

Assertion: Photorespiration is a wasteful process where there is no synthesis of ATP energy.

Reason: RuBisCO is present in mesophyll cells of C4 plants hence they show more productivity.

  • 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.


C.

If assertion is true but reason is false.

Photorespiration does not produce energy or reducing power. Rather it consumes energy. In C4 plants, photorespiration, does not occur. Here, RuBisCO is located only in bundle sheath cells where photosynthetic release of oxygen does not occur. Bundle sheath cells have a high intracellular concentration of CO2 due to flow of C4 acids and their decarboxylation to release CO2Therefore, RuBisCO functions purely as carboxylase in C4 plants. They show high productivity and hence higher yield.


13.

Pacinian corpuscles occur in the skin of certain parts of body in mammals. These are

  • type of glands

  • pain receptors

  • naked tactile receptors

  • encapsulated pressure receptors.


D.

encapsulated pressure receptors.

Pacinian corpuscles occur in the skin of certain parts of the body in mammals. These are encapsulated pressure receptors. Pacinian corpuscles are very rapid adapting pressure receptors in subcutaneous adipose tissue of both hairy and hairless vertebrate skin. They are also found in joint capsules, tendons, etc.


14.

Unidirectional transmission of a nerve impulse through nerve fibre is due to the fact that

  • nerve fibre is insulated by a medullary sheath

  • sodium pump starts operating only at the cyton and then continues into the nerve fibre

  • neurotransmitters are released by dendrites and not by axon endings

  • neurotransmitters are released by the axon endings and not by dendrites.


D.

neurotransmitters are released by the axon endings and not by dendrites.

A synapse occurs where the axon of one neuron (the pre-synaptic neuron) meets the dendrite of another (the post-synaptic neuron). At the tip of the pre-synaptic axon is a button shaped swelling called a synaptic knob, inside which are numerous mitochondria and vesicles packed with a substance called a neurotransmitter which at the time of nerve impulse conduction diffuse across the space and bind to receptors in the membrane of the post-synaptic cell. This opens ion channels in the post-synaptic membrane resulting in a change in its membrane potential and in the consequent generation of a nerve impulse.


15.

Achondroplasia is a disease related with the defect in the formation of

  • membrane

  • cartilage

  • mucosa

  • none of these


B.

cartilage

Achondroplasia is a disorder inherited as dominant characteristic in which bones of arms and legs fail to grow to normal size due to defect in both cartilage and bone. It results in a type of dwarfism characterised by short limbs, a normal sized head and body and normal intelligence.


16.

Which part of the nephron is impermeable to water

  • Proximal convoluted tubule

  • Distal convoluted tubule

  • Ascending limb of loop of Henle

  • Descending limb of loop of Henle


C.

Ascending limb of loop of Henle

Ascending limb of loop of Henle is impermeable to water. Here water is not reabsorbed, rather sodium, potassium, magnesium and chloride are reabsorbed and therefore the filtrate becomes hypotonic to blood plasma.


17.

The checkpoint in cell cycle plays important role in

  • repairing DNA damage

  • apoptosis initiation

  • assessing DNA damage

  • none of these


C.

assessing DNA damage

checkpoint is one of several points in the eukaryotic cell cycle at which the progression of a cell to the next stage in the cycle can be halted until conditions are favourable.


18.

Wharton's duct is the duct of

  • submandibular salivary gland

  • parotid gland

  • sublingual gland

  • all of these


A.

submandibular salivary gland

Wharton's duct is the duct of submandibular salivary gland that opens into the floor of mouth at the junction where front of the tongue meets the mouth's floor.


19.

An artificial pacemaker is implanted subcutaneously and connected to the heart in patients

  • having 90% blockage of the three main coronary arteries

  • having a very high blood pressure

  • with irregularity in the heart rhythm

  • suffering from arteriosclerosis


C.

with irregularity in the heart rhythm

Artificial pacemaker is a medical device designed to regulate the beating of the heart. The purpose of an artificial pacemaker is to stimulate the heart when either the heart's native pacemaker is not fast enough or if there are blocks in the heart's electrical conducting system preventing the propagation of electrical impulses from the native pacemaker to the lower chambers of the heart, known as the ventricles. Generally, pacemakers do not treat fast rhythms of the heart.


20.

C4 plants have better productivity because

  • C4 plants absorb more light

  • C4 plants absorb more CO2

  • C4 plants lack photorespiration

  • all of these


C.

C4 plants lack photorespiration

Presence of photorespiration is considered as a wasteful and energy consuming process in crop plants which ultimately leads to reduction in final yield of crops. It is estimated that during C4 photosynthesis, upto 50% of the CO2 fixed may have to pass through photorespiratory process, thereby resulting in considerable decrease in photosynthetic productivity. In C4 plants, there is some loss of photosynthetic activity on account of photorespiration which is absent in C4 plants and hence they have better productivity.