Tiêu đề Neural Control and Coordination- Ex-2 Solution fie.docx.pdf ✅

20 NEURAL CONTROL AND COORDINATION EXERCISE – 2: Previous Year Questions 1. Match the following columns and select the correct option. [NEET 2020] Column I Column II (a) Organ of Corti (i) Connects middle ear and pharynx (b) Cochlea (ii) Coiled part of the labyrinth (c) Eustachian tube (iii) Attached to the oval window (d) Stapes (iv) Located on the basilar membrane (a) a– iv; b – ii; c –i; d - iii (b) a–i; b – ii; c – iv; d - iii (c) a– ii; b – iii; c –i; d - iv (d) a– iii; b –i; c – iv; d - ii Ans. (a) Sol. (a) Organ of corti is a structure located on the basilar membrane which contains hair cells that act as auditory receptors. (b) Cochlea is the coiled portion of the labyrinth (fluid filled inner ear) (c) Eustachian tube connects the middle ear cavity with the pharynx and helps in equalizing pressure of ear drums. (d) Stapes is one of the ossicles of middle ear and is attached to oval window of cochlea. 2. Which of the following is responsible for maintenance of the body and posture? [NEET 2019] (a) Basilar membrane and otolith organ (b) Hair cell and organ of corti (c) Tectorial membrane and macula (d) Crista ampullaris and macula Ans. (d) Sol. The base of each semi-circular canal is swollen and is called ampulla. This ampulla contains a projecting ridge called crista ampullaris which contains hair cells and supporting cells. Similarly, the otolith organs also have hair cells present in macula. This hair cells responsible for maintaining the balance of body. 3. Which of the following statements is correct? [NEET 2019] (a) Cornea consists of dense connective tissue of elastin and can repair itself (b) Cornea is convex, transparent layer which is highly vascularised (c) Cornea consists of dense matrix of collagen and is the most sensitive portion of the eye. (d) Cornea is an external, transparent and protective proteinaceous covering of the eyeball. Ans. (c) Sol. Cornea consists of dense matrix of collagen and corneal epithelium. It is the most sensitive part of eye. 4. Which of the following statement is not correct? [NEET 2019] (a) An action potential in an axon does not move backward because the segment behind is in the refractory phase. (b) Depolarization of hair cells of cochlea results in the opening of mechanically gated potassium ion channels (c) Rods are very sensitive and contribute to daylight vision. (d) In knee jerk reflex, the stimulus is stretching of muscles and response is its contraction. Ans. (c) Sol. Cones are light sensitive and responsible for day light vision and coloured vision also. Rods are responsible for twilight vision. 5. The transparent lens in the human eye is held in its place by [NEET 2018] (a) smooth muscles attached to the iris (b) ligaments attached to the iris (c) ligaments attached to the ciliary body (d) smooth muscles attached to the ciliary body Ans. (c) Sol. The transparent lens in the eyeball is held in its position due to the ligaments attached to the ciliary body. These ligaments are suspensory in nature. However, it is the smooth muscles in the ciliary body
21 NEURAL CONTROL AND COORDINATION which allows to change the shape of the lens of the eye. 6. Which of the following structures or regions is incorrectly paired with its functions? [NEET 2018] (a) Hypothalamus: production of releasing hormones and regulation of temperature, hunger and thirst (b) Limbic system: consists of fibre tracts that interconnect different regions of brain; controls movement (c) Medulla oblongata: controls respiration and cardiovascular reflexes (d) Corpus callosum: band of fibers connecting left and right cerebral hemispheres Ans. (b) Sol. A group of associated deep structures along with an inner portion of cerebral hemispheres form a complex part called limbic system which has functions of olfaction, autonomic responses, regulation of sexual behavior, expression of emotional reactions, and motivation. 7. Nissl bodies are mainly composed of [NEET 2018] (a) Nucleic acids and SER (b) DNA and RNA (c) Proteins and lipids (d) Free ribosomes and RER Ans. (d) Sol. Nissl bodies are granular structures found in the cyton or cell body of a neuron. These are composed of free ribosomes and rough endoplasmic reticulum which help in protein synthesis. 8. Good vision depends on adequate intake of carotene rich food. Select the best option from the following statements. [NEET 2017] 1) Vitamin A derivatives are formed from carotene. 2) The photopigments are embedded in the membrane discs of the inner segment. 3) Retinal is a derivative of Vitamin A. 4) Retinal is a light absorbing part of all the visual Photopigments. (a) (1) and (2) (b) (1), (3) and (4) (c) (1) and (3) (d) (2), (3) and (4) Ans. (b) Sol. Retinal is a light sensitive photopigment which is a part of rhodopsin which senses low light intensities. Moreover, retinal binds to proteins called opsins in our eye. Vitamin A is very important for the production of retinal. Moreover, vitamin A is derived from beta-carotene. So the consumption of Vitamin A containing food becomes important, such as carrots, broccoli, squash, etc. 9. Receptor sites for neurotransmitters are present on [NEET 2017] (a) Membranes of synaptic vesicles (b) Pre-synaptic membrane (c) Tips of axons (d) Post-synaptic membrane Ans. (d) Sol. The receptor sites bind selectively to the neurotransmitters which travel the synaptic cleft, which are generally present on the post synaptic membrane. However, some exceptions are possible. 10. Myelin sheath is produced by [NEET 2017] (a) Schwann Cells and Oligodendrocytes (b) Astrocytes and Schwann Cells (c) Oligodendrocytes and Osteoclasts (d) Osteoclasts and Astrocytes Ans. (a) Sol. Myelin sheath is the insulating layer, also known as the medullary sheath, present over the axon. This sheath is produced by Schwann cells of the Peripheral Nervous System and Oligodendrocytes of the Central Nervous System. 11. Photosensitive compound in human eye is made up of [NEET 2016] (a) Guanosine and Retinol (b) Opsin and Retinal (c) Opsin and Retinol (d) Transducin and Retinene Ans. (b) Sol. Photosensitive compounds such as rhodopsin is found in rod cells. Rhodopsin contains retinal and opsin. When light falls on retinal its structure changes, upon this changed structure which pushes the opsin, the protein part. The opsin in turn sends a signal to the central nervous system via the optic nerves. Upon which an image is processed by our brain.
22 NEURAL CONTROL AND COORDINATION 12. Choose the correct statement. [NEET 2016] (a) Nociceptors respond to change in pressure (b) Meissner’s corpuscles are thermoreceptors (c) Photoreceptors in the human eye are depolarized during darkness and become hyperpolarized in response to the light stimulus (d) Receptors do not produce graded potentials Ans. (c) Sol. Photoreceptors are unusual cells, where these receptors stay in depolarized condition in darkness. Upon further illumination, the potential difference becomes more negative that is roughly from -40mV to -65mV. Hence, on illumination of light, the photoreceptors become hyperpolarized. 13. In mammalian eye, the ‘fovea' is the center of the visual field, where [NEET 2015] (a) more rods than cones are found (b) high density of cones occurs, but has no rods (c) the optic nerve leaves the eye (d) only rods are present Ans. (b) Sol. Fovea does not contain any rods but has a high density of cones. So, it cannot sense any low light intensity. It can only sense the photopic vision. Photopic vision helps in viewing the colour of objects we view. 14. Destruction of the anterior horn cells of the spinal cord would result in loss of: [NEET 2015] (a) integrating impulses (b) sensory impulses (c) voluntary motor impulses (d) commissural impulses Ans. (c) Sol. Destruction of the anterior horn cells of the spinal cord would result in loss of voluntary motor impulses, because the anterior grey column containing cell bodies of the alpha motor neurons are present. 15. Which of the following region of the brain is incorrectly matched with its function? [NEET 2015] (a) Medulla oblongata – Homeostatic control (b) Cerebellum- Language comprehension (c) Corpus callosum- Communication between right and left cerebral cortices (d) Cerebrum- Calculation and contemplation Ans. (b) Sol. Cerebellum is the part of hind brain, and it is responsible for maintenance of body posture. Language comprehension is done by cerebrum which is the largest part of the brain. 16. A gymnast is able to balance his body upside down even in darkness. It is because of [NEET 2015] (a) Cochlea (b) Vestibular apparatus (c) Tectorial membrane (d) Organ of corti Ans. (b) Sol. Vestibular apparatus is a part of internal ear that is responsible for maintain the balance of the body. It has two parts out of which one is semicircular canal responsible for maintaining the dynamic balance of the body and the other is otolith organ that maintains the static balance of the body. 17. How do parasympathetic neural signals affect the working of the heart? [NEET 2014] (a) Reduce both heart rate and cardiac output (b) Heart rate is increased (c) Both heart rate and cardiac output increase (d) Heart rate decreases but cardiac output increases Ans. (a) Sol. Parasympathetic neural signals (PNS) work just opposite to the effects of the sympathetic neural signal. The PNS decreases the heart rate, which thereby reduces the cardiac output as cardiac output is defined as the product of heart rate and stroke volume. The stroke volume usually never changes and so the only variable factor here becomes heart rate. So, a change in heart rate/beat will cause changes in the cardiac output as well. 18. Stimulation of a muscle fiber by a motor neuron occurs at [NEET 2014] (a) the neuromuscular junction (b) the transverse tubules (c) the myofibril (d) the sarcoplasmic reticulum Ans. (a)
23 NEURAL CONTROL AND COORDINATION Sol. The neuromuscular junction is a region where the neuron dendrites terminate upon the muscle membrane. In between them a gap junction forms which is termed to be the neuromuscular junction. The electric signals are transferred from the neuron onto the muscles via generating neurotransmitters which are released in form of vesicles in the synaptic cleft. These then attach with its respective receptors, and this then generates a graded potential. When several graded potentials combine, depending upon the nature of the neurotransmitter, it can be excitatory post-synaptic potential or inhibitory post-synaptic potential. 19. Which one of the following statements is not correct? [NEET 2014] (a) Retinal is the light absorbing portion of visual photopigments (b) In retina the rods have the photopigment rhodopsin, while cones have three different photopigments (c) Retinal is a derivative of vitamin C (d) Rhodopsin, is the purplish red protein present in rods only Ans. (c) Sol. Retinal is a derivative of Vitamin A. This retinal binds with opsin (protein) to form rhodopsin, the light absorbing portion of photopigments. It can detect light at very low intensities and hence found in rod cells. 20. Injury localized to the hypothalamus would most likely disrupt [NEET 2014] (a) short term memory (b) co-ordination during locomotion (c) executive function, such as decision making (d) regulation of body temperature Ans. (d) Sol. Hypothalamus has the functions of controlling body temperature, eating and drinking. It also has neurosecretory cells which control the secretions of oxytocin and anti-diuretic hormones. It also controls the hormone release of the adenohypophysis or the anterior region of the pituitary gland. 21. A diagram showing axon terminal and synapse is given. Identify correctly at least two of A-D [NEET 2013] (a) A-Receptor, C-Synaptic vesicles (b) B-Synaptic connection, D-K + (c) A-Neurotransmitter, B-Synaptic cleft (d) C-Neurotransmitter, D-Ca 2+ Ans. (a) Sol. In the, diagram it depicts a synaptic junction where labels A, B, C and D represent receptors (which accept the neurotransmitter and pass on the information), synaptic cleft (which is the gap where the neurotransmitters are released in between neurons or a neuromuscular junction), synaptic vesicles (which contain the neurotransmitters) and membrane of the dendrite. 22. Parts A, B, C and D of the human eyes are shown in the diagram. Select the option, which gives correct identification along with its functions/characteristics [NEET 2013]