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MCQOPTIONS
This section includes 14620 Mcqs, each offering curated multiple-choice questions to sharpen your NEET knowledge and support exam preparation. Choose a topic below to get started.
| 13351. |
The plant Cuscuta shows maximum photosynthesis in |
| A. | Red light |
| B. | Blue light |
| C. | Green light |
| D. | No photosynthesis at all |
| Answer» E. | |
| 13352. |
The researches on photosynthesis started |
| A. | In the 17th century |
| B. | In the 18th century |
| C. | In the 19th century |
| D. | In the early 20th century |
| Answer» C. In the 19th century | |
| 13353. |
Chlorophyll converts |
| A. | Light energy into chemical |
| B. | Chemical energy into light |
| C. | Light energy into electrical |
| D. | Electrical energy into food |
| Answer» B. Chemical energy into light | |
| 13354. |
The two light reactions when absorb light drive the flow of electrons against an electrochemical gradient from |
| A. | - 1.1 volt to + 0.8 volt |
| B. | + 0.8 volt to - 0.3 volt |
| C. | + 2.0 volt to + 5.2 volt |
| D. | - 0.5 volt to + 25 volt |
| Answer» C. + 2.0 volt to + 5.2 volt | |
| 13355. |
Elements required for photolysis of water [BHU 2005] |
| A. | Mn |
| B. | Mg |
| C. | Fe |
| D. | Zn |
| Answer» B. Mg | |
| 13356. |
The role of chlorophyll in photosynthesis is [NCERT 1977; CBSE PMT 2002] |
| A. | Absorption of\[C{{O}_{2}}\] |
| B. | Absorption of light |
| C. | Absorption of light and photochemical decomposition of water |
| D. | Absorption of water |
| Answer» D. Absorption of water | |
| 13357. |
Which of the following statements) is/are correct? (i) In a population growth rate curve, the lag phase represents the period when a population is adjusting to a new environment. (ii) In a population growth rate curve the steepest part of growth phase represents the period when a population is growing exponentially. (iii) In the stationary phase of a population growth rate curve, the population is in dynamic equilibrium. (iv) Humans have changed the carrying capacity of the earth. |
| A. | All of these |
| B. | (i), (ii) and (iii) |
| C. | (ii) and (iii) |
| D. | (i) and (iv) |
| Answer» B. (i), (ii) and (iii) | |
| 13358. |
Most molluscs and cry fishes are: |
| A. | Thermoconformers |
| B. | Osmoconformers |
| C. | Oxyregulators |
| D. | All of the above |
| Answer» E. | |
| 13359. |
Which of the following statement(s) is/are correct? (i) Organisms living in oceans, lakes and rivers do not face any water-related problems. (ii) Euryhaline can tolerate a wide range of salinities. (iii) Stenohaline are restricted to a narrow range of salinities. (iv) No fresh water animals cannot live for long in sea water but sea animals can live in fresh water for long time because of osmotic balance. (v) The salt concentration is less than 5% in inland water, 30-50% in sea and >100% in some hypersaline lagoons. |
| A. | All are correct except (i) |
| B. | None of the above |
| C. | Only (iv) |
| D. | (i), (iii) and (iv) |
| Answer» B. None of the above | |
| 13360. |
Mark the correct statement. |
| A. | In case of bear, going into hibernation during winter, is an example of 'escape in time. |
| B. | To prevent desiccation, some snails and fishes enter into diapause. |
| C. | Under unfavourable conditions many zooplankton species go into aestivation. |
| D. | All of the above |
| Answer» B. To prevent desiccation, some snails and fishes enter into diapause. | |
| 13361. |
Identify the incorrect statement. (i) Thermoregulation energetically least expensive process for many organisms like shrews and humming birds. (ii) 99% animals and nearly all plants cannot maintain their constant internal environment. (iii) During the course of evolution, the costs and heights of maintaining a constant internal environment are discarded. (iv) In aquatic animals, the osmotic concentration of the body fluids change with that of the ambient water osmotic concentration. |
| A. | (i) and (ii) |
| B. | (iii) and (iv) |
| C. | (i) and (iii) |
| D. | (ii) and (iii) |
| Answer» D. (ii) and (iii) | |
| 13362. |
Which type of plants are found in Taiga Tundra? |
| A. | Halophytes |
| B. | Xerophytes |
| C. | Epiphytes |
| D. | Psychrophytes |
| Answer» E. | |
| 13363. |
Which one of the following is the interspecific hybrid variety? |
| A. | Mule |
| B. | Sugarcane |
| C. | Pony |
| D. | All of these |
| Answer» E. | |
| 13364. |
Which one of the following is example of species that breed in captivity and produce infertile hybrids? |
| A. | Mallard (a duck) and the pin tail duck |
| B. | Male donkey and female horse |
| C. | Polar bear and the Alaskan brown bear |
| D. | Platy and sword tail fishes |
| Answer» C. Polar bear and the Alaskan brown bear | |
| 13365. |
Which of the following statement is not correct about K-selection? |
| A. | Having long life span |
| B. | Developed Interspecific competition |
| C. | Very stable population |
| D. | Having short generation time |
| Answer» E. | |
| 13366. |
Leaf cutter ants keep fungal gardens. The ants provide food for the fungus but also feed on the fungus. This is an example of |
| A. | Competition |
| B. | Predation |
| C. | Parasitism |
| D. | Mutualism |
| Answer» E. | |
| 13367. |
Why are inducible defenses advantageous? |
| A. | They are always present - thus, an individual is always able to defend itself. |
| B. | They make it impossible for a consumer to launch surprise attacks. |
| C. | They result from a coevolutionary arms race. |
| D. | They make efficient use of resources, because they are produced only when needed. |
| Answer» E. | |
| 13368. |
Pneumatophores are special features of plants growing in: |
| A. | Dry and hot conditions |
| B. | Water |
| C. | Mangrove forests |
| D. | Oligotrophic soils |
| Answer» D. Oligotrophic soils | |
| 13369. |
During summer stratification, the upper layer of water is called: |
| A. | Thermocline |
| B. | Hypolimnion |
| C. | Epilimnion |
| D. | Ectolimnion |
| Answer» D. Ectolimnion | |
| 13370. |
\[\frac{dN}{dt}=rN\left( \frac{K-N}{K} \right)\]A - Population density at time t.B - Intrinsic rate of nature increase.C - Carrying capacity.Identify A, B and C from given equation. |
| A. | ABCNKr |
| B. | NrK |
| C. | KNr |
| D. | KrN |
| Answer» C. KNr | |
| 13371. |
Refer to the graph below, which shows the changes in population size over time. Which part of this graph describes or refers to the exponential growth phase of a new population? |
| A. | 1 |
| B. | 5 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 13372. |
Sunken stomata can be seen in- |
| A. | Hydrilla |
| B. | Nymphaea |
| C. | Acacia |
| D. | Rhizophora |
| Answer» D. Rhizophora | |
| 13373. |
A group of individuals of a plant inhabiting a particular area form a: |
| A. | Population |
| B. | Community |
| C. | Ecosystem |
| D. | Species |
| Answer» B. Community | |
| 13374. |
Biome is: |
| A. | sum of ecosystems in a geographical area. |
| B. | sum of ecosystems of the whole earth. |
| C. | biotic component of an ecosystem. |
| D. | biotic potential of a population. |
| Answer» B. sum of ecosystems of the whole earth. | |
| 13375. |
For plants inhabiting a tropical rain forest, the critical competition, is for- |
| A. | Soil nutrients |
| B. | Water |
| C. | Space |
| D. | Light |
| Answer» E. | |
| 13376. |
Desert regions are characterised by ________ centimeters of rainfall per year. |
| A. | less than 5 |
| B. | less than 15 |
| C. | less than 25 |
| D. | over 50 |
| Answer» D. over 50 | |
| 13377. |
In commensalism: |
| A. | population of commensal and host remains unaffected. |
| B. | population of commensal may increase while that of host remains unaffected. |
| C. | population of both commensal and host increases. |
| D. | population of commensal increases while the population of host gradually decreases. |
| Answer» C. population of both commensal and host increases. | |
| 13378. |
Which of the following statement(s) is/are incorrect? (i) Plants have no thermoregulation. (ii) 99% animals and almost all plants are conformers. (iii) Heat loss or heat gain is a function of surface area. (iv) Thermoregulation is energetically least expensive process for many organisms like shrews and humming birds. (v) 99% animals are thermoregulators. (vi) Archaebacteria cannot tolerate high temperature. |
| A. | (i) and (ii) |
| B. | (iv), (v) and (vi) |
| C. | None of these |
| D. | All of these |
| Answer» C. None of these | |
| 13379. |
In biotic community, which of the following can be called protective device? |
| A. | Mimicry |
| B. | Symbiosis |
| C. | Competition |
| D. | Parasitism |
| Answer» B. Symbiosis | |
| 13380. |
In an age pyramid, the number of individuals of reproductive age is lesser than pre-reproductive but higher than post reproductive ones. The population is: |
| A. | Growing |
| B. | Declining |
| C. | Stable |
| D. | Can not be predicted |
| Answer» B. Declining | |
| 13381. |
Photosynthetically Active Radiation (PAR) is: |
| A. | 5% of incident solar radiation |
| B. | 50% of incident solar radiation |
| C. | 0.5% of incident solar radiation |
| D. | 99% of incident solar radiation |
| Answer» C. 0.5% of incident solar radiation | |
| 13382. |
Organisms occupying similar ecological niche but different geographical areas of distribution are called as: |
| A. | Edge species |
| B. | Ecological equivalents |
| C. | Ecoclines |
| D. | Inquilines |
| Answer» C. Ecoclines | |
| 13383. |
If b=65 and d = 45, N = 100 then find out \[\frac{dN}{dt.}\] |
| A. | 2000 |
| B. | 1000 |
| C. | 200 |
| D. | 100 |
| Answer» B. 1000 | |
| 13384. |
Which of the following type of interactions occur in predation and parasitism? |
| A. | (+, +) |
| B. | (+, 0) |
| C. | (+, -) |
| D. | (-, -) |
| Answer» D. (-, -) | |
| 13385. |
No population can grow indefinitely. The ultimate size of any population is limited by: |
| A. | the carrying capacity of its environment. |
| B. | its birth rate. |
| C. | its intrinsic growth rate. |
| D. | reproductive isolation. |
| Answer» B. its birth rate. | |
| 13386. |
Explosive growth in human population size can be attributed largely to: |
| A. | declining death rates due to improved medical care. |
| B. | proliferation of fast-food outlets, leading to easier access to nutrients. |
| C. | increasing birth rates due to better health and fertility. |
| D. | declining death rates due to declining incidence of war. |
| Answer» B. proliferation of fast-food outlets, leading to easier access to nutrients. | |
| 13387. |
Which of the following is not a reason why population growth declines as population size approaches the carrying capacity? |
| A. | Climate becomes unfavorable. |
| B. | Competition for resources increases. |
| C. | Predation rates increase. |
| D. | Disease rates increase. |
| Answer» B. Competition for resources increases. | |
| 13388. |
The parts of the neurons that perform basic cellular functions such as protein synthesis are the: |
| A. | Axons |
| B. | Dendrites |
| C. | Synaptic knobs |
| D. | Soma |
| Answer» E. | |
| 13389. |
Nerve impulses are initiated by nerve fibres only when the membrane shall become more permeable to: |
| A. | Adrenaline |
| B. | Phosphorus |
| C. | Sodium ions |
| D. | Potassium ions |
| Answer» D. Potassium ions | |
| 13390. |
The autonomic nervous system has control over: |
| A. | Reflex action |
| B. | Sense organs |
| C. | Internal organs |
| D. | skeletal muscles |
| Answer» D. skeletal muscles | |
| 13391. |
Which of the following statements is incorrect about cones? (i) The daylight vision and colour vision are function of cones. (ii) In human eye, there are three types of cones having characteristic photopigments that respond to red, green and blue light. (iii) The sensations of different colours are produced by various combination of these 3 types of cones. (iv) When these 3 types of cones are stimulated equally, a sensation of white light is produced. |
| A. | Only (iv) |
| B. | Only (i) and (iv) |
| C. | Only (iii) |
| D. | none of these |
| Answer» E. | |
| 13392. |
Neurons receive signals through their _____ and send signals to other neurons through their |
| A. | Dendrites ... receptors |
| B. | End feet... cell bodies and dendrites |
| C. | Cell bodies and dendrites ... axons |
| D. | Transmitter vesicles ... axons |
| Answer» D. Transmitter vesicles ... axons | |
| 13393. |
The nodes of Ranvier are: |
| A. | The points in which the axons is exposed. |
| B. | The contact points found over the non-myelinated nerve fibre. |
| C. | Areas in which the axons swell up. |
| D. | Areas where the neurilemma touches the axon. |
| Answer» B. The contact points found over the non-myelinated nerve fibre. | |
| 13394. |
Ear drum is known as: |
| A. | Tympanic membrane |
| B. | Tensor tympani |
| C. | Scala tympani |
| D. | Scala vestibule |
| Answer» B. Tensor tympani | |
| 13395. |
The small canal leading from pinna into the head in mammals is: |
| A. | Haversian canal |
| B. | Ext. auditory meatus |
| C. | Inguinal canal |
| D. | Eustachian tube |
| Answer» C. Inguinal canal | |
| 13396. |
Center for sense of smell is: |
| A. | Cerebellum |
| B. | Olfactory lobes |
| C. | Cerebrum |
| D. | Midbrain |
| Answer» D. Midbrain | |
| 13397. |
Route of reflex arc is: |
| A. | Receptors, effectors, grey mater and motor fibres |
| B. | Receptors, sensory fibres, grey mater, motor fibres and effectors |
| C. | Sensory fibres, grey mater, motor-fibres, receptors and effectors |
| D. | Effectors, grey mater, motor, sensory fibres and receptors |
| Answer» C. Sensory fibres, grey mater, motor-fibres, receptors and effectors | |
| 13398. |
Our ear can hear the frequency of sound waves |
| A. | 20 to 20,000 cycles/sec |
| B. | 1000 to 2000 cycles/sec |
| C. | 5000 to 7000 cycles/sec |
| D. | 5000 to 10,000 cycles/sec |
| Answer» B. 1000 to 2000 cycles/sec | |
| 13399. |
The eyes of tigers and wolves shine (reflect back the light focused on them) because: |
| A. | Cornea is opaque |
| B. | Retina does not have enough rods |
| C. | Retina has only rods and no cones |
| D. | None of the above |
| Answer» E. | |
| 13400. |
An example of autonomous nervous system is: |
| A. | Swallowing food |
| B. | Pupillary reflex |
| C. | Peristalsis of intestine |
| D. | Knee-jerk response |
| Answer» D. Knee-jerk response | |