Which one of the following pairs of structures distinguishes a nerve cell from other types of cells?
1. Nucleus and mitochondria
2. Perikaryon and dendrites
3. Vacuoles and fibres
4. Flagellum and medullary sheath
During the propagation of a nerve impulse, the action potential results from the movement of
1. Na+ ions from extracellular fluid to intracellular fluid.
2. K+ ions from extracellular fluid to intracellular fluid.
3. Na+ ions from intracellular fluid to extracellular fluid.
4. K+ ions from intracellular fluid to extracellular fluid.
Select the answer with correct matching of the structure, its location and function.
Structure |
Location |
Function |
|
1. |
Cerebellum |
Midbrain |
Controls respiration and gastric secretions |
2. |
Hypothalamus |
Forebrain |
Controls body temperature, urge for eating and drinking |
3. |
Blind spot |
Near the place where optic nerve leaves the eye |
Rods and cones are present but inactive here |
4. |
Eustachian tube |
Anterior part of internal ear |
Equalizes air pressure on either side of tympanic membrane |
Most of the neurons in the cerebral cortex are:
1. | Unipolar | 2. | Bipolar |
3. | Multipolar | 4. | Pseudounipolar |
The resting axonal membrane is impermeable/nearly impermeable to:
I. Sodium ions
II. Potassium ions
III. Negatively charged proteins
1. | Only I and II | 2. | Only I and III |
3. | Only II and III | 4. | I, II and III |
Match the parts of the human brain in Column I with function in Column II and select the answer from the codes given:
Column I | Column II | ||
A. | Medulla oblongata | a. | Coordinating center for sensory and motor signaling |
B. | Thalamus | b. | Regulation of gastric secretions |
C. | Hypothalamus | c. | Thermoregulation and osmoregulation |
D. | Hippocampus | d. | Consolidation of short term memory into long term memory |
Codes
A | B | C | D | |
1. | a | b | c | d |
2. | b | a | d | c |
3. | a | b | d | c |
4. | b | a | c | d |
In the resting state of the neural membrane, diffusion due to concentration gradients, if allowed, would drive
1. K+ and Na+ out of the cell.
2. Na+ into the cell.
3. Na+ out of the cell.
4. K+ into the cell.
Consider the two statements:
I. Electrical synapses are rare in our system.
II. Electrical synapses conduct impulse faster than the chemical synapse.
1. Both I and II are correct and II explains I
2. Both I and II are correct but II does not explain I
3. Only I is correct
4. Both I and II are incorrect
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion (A): | Most of the synapses in vertebrates conduct information in only one direction. |
Reason (R): | Only the postsynaptic cells can bind and respond to neurotransmitters. |
In the light of the above statements choose the correct answer from the options given below:
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion (A): | Electrical synapses are faster but rare in human beings. |
Reason (R): | Electrical synapses contain gap junctions that allow electric current to flow directly from one neuron to another. |
In the light of the above statements choose the correct answer from the options given below:
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |