Biology - Mock Test 83

Question 821

If vagus nerve in man is damaged, which of the following will not be affected?

A) pancreatic secretion B) gastrointestinal movements C) tongue movements D) cardiac movements

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Question 822

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

A) nerve fibre is insulated by a medullary sheath B) sodium pump starts operating only at the cyton and then continues into the nerve fibre C) neurotransmitters are released by dendrites and not by axon endings D) neurotransmitters are released by the axon endings and not by dendrites

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Question 823

Patients suffering from cholera are given a saline drip because ?

A) NaCl is an important component of energy supply B) NaCl furnishes most of the fuel required for cellular activity C) Na+ ions help in stopping nerve impulses and hence, sensation of pain D) Na+ ions help in the retention of water in the body tissues

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Question 824

During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric charge?

A) First positive, then negative and continue to be negative B) First negative, then positive and again back to negative C) First positive, then negative and again back to positive D) First negative, then positive and continue to be positive.

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Question 825

Which one of the following is an example of negative feedback loop in humans?

A) Constriction of skin blood vessels and contraction of skeletal muscles when it is too cold B) Secretion of tears after falling of sand particles into the eyes C) Salivation of mouth at the sight of delicious food D) Secretion of sweat glands and constriction of skin blood vessels when it is too hot

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Question 826

Which one of the following pairs of structures distinguishes a nerve cell from other types of cell?

A) Perikaryon and dendrites B) Vacuoles and fibres C) Flagellum and medullary sheath D) Nucleus and mitochondria

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Question 827

The cutaneous plexus and the papillary plexus consist of ?

A) Specialized cells for cutaneous sensations B) A network of arteries to provide dermal supply C) A network of nerves to provide dermal sensation D) Gland cells that release cutaneous secretions

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Question 828

An action potential in the nerve fibre is produced when positive and negative charges on outside and the inside of the axon membrane are reversed because ?

A) all potassium ions leave the axon B) more potassium ions enter the axon as compared to sodium ions leaving it C) more sodium ions enter the axon as compared to potassium ions leaving it D) all sodium ions enter the axon

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Question 829

Which one of the following aspects is an exclusive characteristic of living things?

A) Perception of events happening in the environment and their memory B) Increase in mass by accumulation of material both on surface as well as internally C) Isolated metabolic reactions occur in vitro D) Increase in mass from inside only

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Question 830

Which one of the followings is not correct about neuroglial cells?

A) Generate or transmit impulses B) Maintain healthy concentrations of important chemicals in the fluid C) Provide physical support and protection to neurons D) In PNS, responsible for myelination (Schwann cells)

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