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All questions of Organisms and Populations for NEET Exam
Biological organisation starts witha) Cellular levelb) Atomic levelc) Submicroscopic molecular leveld) Organismic levelCorrect answer is option 'C'. Can you explain this answer?
|
Rohit Shah answered |
Correct option is (c)
Biological organisation starts with submicroscopic molecular level, where four types of molecules, i.e. carbohydrates, lipids, proteins and nucleic acid are organised into organelles of cell.
Biological organisation starts with submicroscopic molecular level, where four types of molecules, i.e. carbohydrates, lipids, proteins and nucleic acid are organised into organelles of cell.
Animals undergo an inactive stage during the winter known as- a)Adaptation
- b)Hibernation
- c)Aestivation
- d)Acclimatisation
Correct answer is option 'B'. Can you explain this answer?
Animals undergo an inactive stage during the winter known as
a)
Adaptation
b)
Hibernation
c)
Aestivation
d)
Acclimatisation
|
Vijay Bansal answered |
Aestivation: Aestivation is summer sleep and during aestivation, animals usually tend to rest in a shady and cool place. ... In aestivation, usually cold blooded animals like reptiles maintain their body temperature by reducing their metabolic activities and protecting themselves from very high temperature.
Organisms capable of maintaining constant body temperature are- a)Poikilothermal
- b)Conformers
- c)Stenothermal
- d)Homeothermal
Correct answer is option 'D'. Can you explain this answer?
Organisms capable of maintaining constant body temperature are
a)
Poikilothermal
b)
Conformers
c)
Stenothermal
d)
Homeothermal
|
Pooja Mehta answered |
Homeotherms: animals who maintain a constant internal body temperature across a wide range of environmental conditions. Most mammals and birds are homeotherms.
In which of the following interactions both partners are adversely affected ?[2015 RS]- a)Predation
- b)Parasitism
- c)Mutualism
- d)Competition
Correct answer is option 'D'. Can you explain this answer?
In which of the following interactions both partners are adversely affected ?
[2015 RS]
a)
Predation
b)
Parasitism
c)
Mutualism
d)
Competition
|
Priyanka Iyer answered |
(d) Competition occurs for light, food and space among organisms in which all partners are adversely affected in an ecosystom.
Which of the following is/are poikilotherm:?- a)Tapeworm and rabbits
- b)Elephants
- c)Humans and fishes
- d)Tapeworm and naked mole rat
Correct answer is option 'D'. Can you explain this answer?
Which of the following is/are poikilotherm:?
a)
Tapeworm and rabbits
b)
Elephants
c)
Humans and fishes
d)
Tapeworm and naked mole rat
|
Divey Sethi answered |
In the given scenario, the laboratory population of fruit flies consists of 40 fruit flies, and during a specified time interval, 4 individuals died. To calculate the death rate, we divide the number of deaths by the total population.
Number of deaths = 4
Total population = 40
Total population = 40
Death rate = Number of deaths / Total population
= 4 / 40
= 0.1 individuals per fruitfly per week
= 4 / 40
= 0.1 individuals per fruitfly per week
Option a) "0.1 individuals per fruitfly per week" is the correct answer because it accurately represents the death rate calculated based on the given information.
Xerophytes are mostly- a)Succulents
- b)Water related
- c)Mesophytes
- d)None of the above
Correct answer is option 'A'. Can you explain this answer?
Xerophytes are mostly
a)
Succulents
b)
Water related
c)
Mesophytes
d)
None of the above
|
|
Pooja Mehta answered |
Plants adapted to living in dry environments such as succulents are termed xerophytes. However, not all xerophytes are succulents, since there are other ways of adapting to a shortage of water, e.g., by developing small leaves which may roll up or having leathery rather than succulent leaves.
Cold-blooded animals fall under the category of- a)Psychotherms
- b)Ectotherms
- c)Thermophiles
- d)Endotherms
Correct answer is option 'B'. Can you explain this answer?
Cold-blooded animals fall under the category of
a)
Psychotherms
b)
Ectotherms
c)
Thermophiles
d)
Endotherms
|
|
Priya Patel answered |
An ectotherm "outside" and "hot"), is an organism in which internal physiological sources of heat are of relatively small or quite negligible importance in controlling body temperature.] Such organisms (for example frogs) rely on environmental heat sources,which permit them to operate at very economical metabolic rates. Colloquially, some refer to these organisms as "cold blooded" though such a term is not technically correct, as the blood temperature of the organism varies with ambient environmental temperature. Some of these animals live in environments where temperatures are practically constant, as is typical of regions of the abyssal ocean and hence can be regarded as homeothermic ectotherms. In contrast, in places where temperature varies so widely as to limit the physiological activities of other kinds of ectotherms, many species habitually seek out external sources of heat or shelter from heat; for example, many reptiles regulate their body temperature by basking in the sun, or seeking shade when necessary in addition to a whole host of other behavioral thermoregulation mechanisms. For home captivity as pet, reptile owners can use a UVB/UVA light system to assist the animals' basking behaviour.
A statement 933 females per 1000 males depict:- a)ecological ages
- b)generation time
- c)sex ratio
- d)biotic potential
Correct answer is option 'C'. Can you explain this answer?
A statement 933 females per 1000 males depict:
a)
ecological ages
b)
generation time
c)
sex ratio
d)
biotic potential
|
Aman Sharma answered |
Sex ratio is the no of female available per thousands of male in a population. Sex ratio is decline due to female feticides alarmingly in some part of India.
Orchid shows commensalism as interaction with:- a)bee
- b)mango tree
- c)both mango tree and bee
- d)none of these
Correct answer is option 'B'. Can you explain this answer?
Orchid shows commensalism as interaction with:
a)
bee
b)
mango tree
c)
both mango tree and bee
d)
none of these
|
Shivani Rane answered |
Commensalism is interaction in which one species is benefited by other is neither benefited nor harmed. Orchids growing on mango tree do not harm the mango plants but get shelter.
Cuscuta is an example of[2012M]- a)ectoparasitism
- b)brood parasitism
- c)predation
- d)endoparasitism
Correct answer is option 'A'. Can you explain this answer?
Cuscuta is an example of
[2012M]
a)
ectoparasitism
b)
brood parasitism
c)
predation
d)
endoparasitism
|
Mrinalini Bajaj answered |
Cuscuta, or Dodder plant, is a parasitic plant that wraps around other plants for nourishment. Cuscuta is found on outer side of the host and is total stem parasite. Cuscuta a parasite of Acacia.
Small fish get stuck near the bottom of a shark and derive their nutrition from it? This kind of association is called- a)Parasitism
- b)Symbiosis
- c)Predation
- d)Commensalism
Correct answer is option 'D'. Can you explain this answer?
Small fish get stuck near the bottom of a shark and derive their nutrition from it? This kind of association is called
a)
Parasitism
b)
Symbiosis
c)
Predation
d)
Commensalism
|
Sonal Chakraborty answered |
Commensalism is a type of symbiotic relationship where one species benefits from the association, while the other is neither harmed nor helped. In this type of association, one species derives benefits from the other without causing any harm to the host.
Explanation:
In the given scenario, the small fish gets stuck near the bottom of a shark and derives its nutrition from it. The small fish is not harming the shark, nor is it providing any benefits to the shark. Therefore, this is an example of commensalism.
The small fish is using the shark as a shelter and also gets access to food particles that are present near the shark's mouth. The shark is not affected by the presence of the small fish, and it does not derive any benefit from it either.
In summary, commensalism is a type of symbiotic relationship where one species benefits from the association, while the other is neither harmed nor helped. The small fish getting stuck near the bottom of a shark and deriving its nutrition from it is an example of commensalism.
Explanation:
In the given scenario, the small fish gets stuck near the bottom of a shark and derives its nutrition from it. The small fish is not harming the shark, nor is it providing any benefits to the shark. Therefore, this is an example of commensalism.
The small fish is using the shark as a shelter and also gets access to food particles that are present near the shark's mouth. The shark is not affected by the presence of the small fish, and it does not derive any benefit from it either.
In summary, commensalism is a type of symbiotic relationship where one species benefits from the association, while the other is neither harmed nor helped. The small fish getting stuck near the bottom of a shark and deriving its nutrition from it is an example of commensalism.
Gause's principle of competitive exclusion states that :[2016]- a)more abundant species will exclude the less abundant species through competition.
- b)competition for the same resources excludes species having different food preferences.
- c)no two species can occupy the same niche indefinitely for the same limiting resources.
- d)larger organisms exclude smaller ones through competition.
Correct answer is option 'C'. Can you explain this answer?
Gause's principle of competitive exclusion states that :
[2016]
a)
more abundant species will exclude the less abundant species through competition.
b)
competition for the same resources excludes species having different food preferences.
c)
no two species can occupy the same niche indefinitely for the same limiting resources.
d)
larger organisms exclude smaller ones through competition.
|
Pallabi Reddy answered |
(c) Gause's principle of competitive exclusion can be restated to say that no two species can occupy the same niche indefinitely when resources are limiting. Certainly species can and do coexist while competing for some of the same resources. Nevertheless, Gause's theory predicts that when two species coexist on a long-term basis, either resources must not be limited or their niches will always differ in one or more features; otherwise, one species will outcompete the other and the extinction of the second species will inevitably result, a process referred to as competitive exclusion
The birth rate if 7 new plants are added to previous year plant population of 23 Salvinia plants will be:- a)0.3
- b)0.25
- c)0.4
- d)0.5
Correct answer is option 'A'. Can you explain this answer?
The birth rate if 7 new plants are added to previous year plant population of 23 Salvinia plants will be:
a)
0.3
b)
0.25
c)
0.4
d)
0.5
|
|
Wahid Khan answered |
The birth rate of a population = new individual added / previous population. Here birth rate= 7/23=0.3043. Hence, birth rate of Salvinia plants is equal to 0.3.###@
A large regional unit characterised by a major vegetation type and associated fauna found in a specific climate zone constitutes- a)Biological community
- b)Ecosystem
- c)Biome
- d)Habitat
Correct answer is option 'C'. Can you explain this answer?
A large regional unit characterised by a major vegetation type and associated fauna found in a specific climate zone constitutes
a)
Biological community
b)
Ecosystem
c)
Biome
d)
Habitat
|
Gaurav Kumar answered |
A biome is a community of plants and animals that have common characteristics for the environment they exist in. They can be found over a range of continents. Biomes are distinct biological communities that have formed in response to a shared physical climate."Biome" is a broader term than "habitat"; any biome can comprise a variety of habitats.
While a biome can cover large areas, a microbiome is a mix of organisms that coexist in a defined space on a much smaller scale. For example, the human microbiome is the collection of bacteria, viruses, and other microorganisms that are present on or in a human body.
A 'biota' is the total collection of organisms of a geographic region or a time period, from local geographic scales and instantaneous temporal scales all the way up to whole-planet and whole-timescale spatiotemporal scales. The biotas of the Earth make up the biosphere.
When does the growth rate of a population following the logistic model equal zero ? The logistic model is given as dN/dt = rN(1–N/K)[2016]- a)when N/K is exactly one.
- b)when N nears the carrying capacity of the habitat.
- c)when N/K equals zero.
- d)when death rate is greater than birth rate.
Correct answer is option 'A'. Can you explain this answer?
When does the growth rate of a population following the logistic model equal zero ? The logistic model is given as dN/dt = rN(1–N/K)
[2016]
a)
when N/K is exactly one.
b)
when N nears the carrying capacity of the habitat.
c)
when N/K equals zero.
d)
when death rate is greater than birth rate.
|
|
Pallabi Reddy answered |
Carnivorous animals lions and leopards, occupy the same niche but lions predate mostly larger animals and leopards take smaller ones. This mechanism of competition is referred to as [2019]- a)Character displacement
- b)Altruism
- c)Resource partitioning
- d)Competitive exclusion.
Correct answer is option 'C'. Can you explain this answer?
Carnivorous animals lions and leopards, occupy the same niche but lions predate mostly larger animals and leopards take smaller ones. This mechanism of competition is referred to as [2019]
a)
Character displacement
b)
Altruism
c)
Resource partitioning
d)
Competitive exclusion.
|
|
Vijay Bansal answered |
Species facing competition might evolve mechanism that promotes co-existence rather exclusion. One such mechanism is resource partitioning.
Resource partitioning is the division of limited resources by species to help avoid competition in an ecological niche. Example - carnivorous animals like lions, leopards occupy the same niche but lions predate mostly larger animals and leopards take smaller ones.
So, correct answer is option C.
Interacting members of species live close to each other in following interaction/s:- a)parasitism
- b)competition
- c)commensalism, predation and parasitism
- d)commensalism
Correct answer is option 'C'. Can you explain this answer?
Interacting members of species live close to each other in following interaction/s:
a)
parasitism
b)
competition
c)
commensalism, predation and parasitism
d)
commensalism
|
Sushant Goyal answered |
Interacting members of species live close to each other in commensalism, predation and parasitism.
Mycorrhiza represents - a)symbiotic association between a fungus and liverworts
- b)parasitic association between a fungus and an alga
- c)parasitic association between a fungus and roots of plants
- d)symbiotic association between a fungus and roots of higher plants
Correct answer is option 'D'. Can you explain this answer?
Mycorrhiza represents
a)
symbiotic association between a fungus and liverworts
b)
parasitic association between a fungus and an alga
c)
parasitic association between a fungus and roots of plants
d)
symbiotic association between a fungus and roots of higher plants
|
Sonal Kulkarni answered |
A nutrient depletion zone can develop when there is rapid soil solution uptake, low nutrient concentration, low diffusion rate, or low soil moisture. These conditions are very common; therefore, most plants rely on fungi to facilitate the uptake of minerals from the soil. Mycorrhizae, known as root fungi, form symbiotic associations with plant roots. In these associations, the fungi are actually integrated into the physical structure of the root. The fungi colonize the living root tissue during active plant growth.
Human population follows the- a)J-shaped growth curve
- b)Z-shaped growth curve
- c)S-shaped growth curve
- d)All of the above
Correct answer is option 'C'. Can you explain this answer?
Human population follows the
a)
J-shaped growth curve
b)
Z-shaped growth curve
c)
S-shaped growth curve
d)
All of the above
|
Harshitha Chavan answered |
Logarithmic or Exponential phase : It is characterized by rapid growth in population which continues till enough food is available. But with the increase in reindeer population, there is corresponding decrease in the availability of food and space, which finally become exhausted, which leads to mass starvation and mortality. This sudden increase in mortality is called population crash. Lemming of Tundra, some insect, algal blooms and annual plants also show J-shaped curves. The population growth curve is S- shaped in most of the organisms, Human population also shows S-shaped curve.
Exponential growth pattern in a population results into:- a)Sigmoid curve
- b)U-shaped curve
- c)J-shaped curve
- d)None of these
Correct answer is option 'C'. Can you explain this answer?
Exponential growth pattern in a population results into:
a)
Sigmoid curve
b)
U-shaped curve
c)
J-shaped curve
d)
None of these
|
Shalini Saha answered |
Exponential growth pattern in population results into j-shaped curve. During exponential growth faster growth occurs and j-shaped curve is formed when time v/s growth is drawn.
In a population unrestricted reproductive capacity is called as[2002]- a)biotic potential
- b)fertility
- c)carrying capacity
- d)birth rate
Correct answer is option 'A'. Can you explain this answer?
In a population unrestricted reproductive capacity is called as
[2002]
a)
biotic potential
b)
fertility
c)
carrying capacity
d)
birth rate
|
Charvi Shah answered |
Carrying capacity refers to the maximum number of individuals that can be sustained by the environment. Birth rate refers to number of births per unit population.
The formula for exponential population growth is- a)dN/rN = dt
- b)r N/dN = dt
- c)dt/dN = r N
- d)dN/dt = r N
Correct answer is option 'D'. Can you explain this answer?
The formula for exponential population growth is
a)
dN/rN = dt
b)
r N/dN = dt
c)
dt/dN = r N
d)
dN/dt = r N
|
Abhiram Nair answered |
Ans.
Formula = the rate of change in population size) = (the contribution of each individual to population growth) x (the number of individuals in the population
In which of the following interaction/s one species is benefitted while other is harmed?- a)parasitism only
- b)competition only
- c)predation and parasitism
- d)competition and amensalism
Correct answer is option 'C'. Can you explain this answer?
In which of the following interaction/s one species is benefitted while other is harmed?
a)
parasitism only
b)
competition only
c)
predation and parasitism
d)
competition and amensalism
|
Nayanika Dasgupta answered |
In predation and parasitism one species is benefitted while other is harmed. Parasite obtain food from host by harming them.
For which of the following would you expect distribution range to be badly affected if average Global temperature keeps increasing:- a)Stenothermal species
- b)Euryhaline species
- c)Both Stenothermal species and Euryhaline species
- d)Eurythermal species
Correct answer is option 'A'. Can you explain this answer?
For which of the following would you expect distribution range to be badly affected if average Global temperature keeps increasing:
a)
Stenothermal species
b)
Euryhaline species
c)
Both Stenothermal species and Euryhaline species
d)
Eurythermal species
|
Diya Datta answered |
A majority of organisms are restricted to narrow range of temperature. Such organisms are called stenothermal species. The distribution range of these species will be adversely affected if average global temperature keeps increasing.
Ecology is the study of the relationships between living organisms and:- a)Abiotic and biotic components
- b)Biotic components only
- c)Abiotic components only
- d)Non-living components only
Correct answer is option 'A'. Can you explain this answer?
Ecology is the study of the relationships between living organisms and:
a)
Abiotic and biotic components
b)
Biotic components only
c)
Abiotic components only
d)
Non-living components only
|
Milan Unni answered |
Ecology is the branch of biology that studies the relationships between living organisms and their environment. It is concerned with understanding how organisms interact with both the biotic (living) and abiotic (non-living) components of their surroundings.
An example of predation is :- a)Cuckoo laying eggs in crow’s nest
- b)Biological control of pest population
- c)Penicilliumwhose toxins kill bacteria
- d)None of the these
Correct answer is option 'B'. Can you explain this answer?
An example of predation is :
a)
Cuckoo laying eggs in crow’s nest
b)
Biological control of pest population
c)
Penicilliumwhose toxins kill bacteria
d)
None of the these
|
Abhishek Choudhary answered |
Biological control method adopted in agricultural pest control are based on the ability of predator to regulate prey population.
“In Competition, the superior competitor eliminates the inferior one”, this statement is called?- a)Gause’s principle
- b)Allen’s rule
- c)Darwinian fitness
- d)All of these
Correct answer is option 'A'. Can you explain this answer?
“In Competition, the superior competitor eliminates the inferior one”, this statement is called?
a)
Gause’s principle
b)
Allen’s rule
c)
Darwinian fitness
d)
All of these
|
Rajesh Datta answered |
E In competition, superior competitor eliminates the inferior one. This statement is called Gause’s competitive exclusion principle. Two closely related competing for same resources cannot co-exist indefinitely and inferior will be eliminated.
Species facing competition might evolve mechanism that promotes co-existence rather than exclusion and that mechanism can be- a)Interspecific competition
- b)Intraspecific competition
- c)Competitive release
- d)Resource partitioning
Correct answer is option 'D'. Can you explain this answer?
Species facing competition might evolve mechanism that promotes co-existence rather than exclusion and that mechanism can be
a)
Interspecific competition
b)
Intraspecific competition
c)
Competitive release
d)
Resource partitioning
|
Pooja Choudhary answered |
Species facing completion might evolve mechanism that promotes co-existence rather than exclusion that mechanism is called resource partitioning. In which they avoid completion by choosing different times of feeding or different foraging patterns.
Which of the following is not an attribute of a population? [2020]- a)Mortality
- b)Species interaction
- c)Sex ratio
- d)Natality
Correct answer is option 'B'. Can you explain this answer?
Which of the following is not an attribute of a population? [2020]
a)
Mortality
b)
Species interaction
c)
Sex ratio
d)
Natality
|
Hrishikesh Rane answered |
Attributes of a Population:
A population is a group of individuals of the same species occupying a particular geographical area. The attributes of a population are:
1. Mortality: The death rate of a population is an important attribute. It is the number of deaths per unit time in a population.
2. Natality: The birth rate of a population is the number of individuals born per unit time in a population. It is an important attribute that determines the growth of a population.
3. Sex ratio: The proportion of males and females in a population is an important attribute. It affects the breeding patterns and reproductive success of a population.
4. Age structure: The proportion of individuals of different age groups in a population is an important attribute. It affects the growth rate and survival of a population.
5. Density: The number of individuals per unit area is an important attribute. It affects the resource availability and competition for resources.
6. Distribution: The spatial arrangement of individuals in a population is an important attribute. It affects the interactions between individuals and their environment.
Explanation:
Species interaction is not an attribute of a population because it involves the interactions between different species, not just individuals of the same species in a population. Population attributes are specific to a particular species occupying a particular geographical area.
A population is a group of individuals of the same species occupying a particular geographical area. The attributes of a population are:
1. Mortality: The death rate of a population is an important attribute. It is the number of deaths per unit time in a population.
2. Natality: The birth rate of a population is the number of individuals born per unit time in a population. It is an important attribute that determines the growth of a population.
3. Sex ratio: The proportion of males and females in a population is an important attribute. It affects the breeding patterns and reproductive success of a population.
4. Age structure: The proportion of individuals of different age groups in a population is an important attribute. It affects the growth rate and survival of a population.
5. Density: The number of individuals per unit area is an important attribute. It affects the resource availability and competition for resources.
6. Distribution: The spatial arrangement of individuals in a population is an important attribute. It affects the interactions between individuals and their environment.
Explanation:
Species interaction is not an attribute of a population because it involves the interactions between different species, not just individuals of the same species in a population. Population attributes are specific to a particular species occupying a particular geographical area.
Which of the following adaptations are examples of plant defenses against herbivores?- a)Thorns on Acacia trees.
- b)High reproductive rate of a parasitic plant.
- c)Chemical production in Calotropis that harms herbivores.
- d)Camouflage in insects like the Monarch butterfly.
Correct answer is option 'A'. Can you explain this answer?
a)
Thorns on Acacia trees.
b)
High reproductive rate of a parasitic plant.
c)
Chemical production in Calotropis that harms herbivores.
d)
Camouflage in insects like the Monarch butterfly.
|
|
Janhavi Bose answered |
Understanding Plant Defenses Against Herbivores
Plants have evolved various strategies to protect themselves from herbivores, which can cause significant damage. Among the adaptations listed, thorns on Acacia trees serve as a primary example of a plant defense mechanism.
Thorns on Acacia Trees
- Physical Barrier:
Thorns act as a physical deterrent, making it difficult for herbivores to consume the leaves and stems of the tree. This adaptation helps reduce the likelihood of being eaten.
- Predator Attraction:
In some cases, Acacia trees also have mutualistic relationships with ants. The thorns can provide shelter for these ants, which, in return, defend the tree by attacking herbivores.
Other Options Explained
- High Reproductive Rate of a Parasitic Plant:
This adaptation is not a defense mechanism but rather a strategy for survival and dispersal. Parasitic plants rely on host plants for nutrients, not defending themselves from herbivores.
- Chemical Production in Calotropis:
While this adaptation does harm herbivores, it is more of a chemical defense rather than a structural one. It represents a different category of defense mechanisms.
- Camouflage in Insects like the Monarch Butterfly:
This is an adaptation of the insect and does not pertain to plant defenses. It highlights predator evasion rather than plant strategies against herbivores.
Conclusion
In summary, thorns on Acacia trees exemplify physical defenses that discourage herbivores, while the other options either pertain to different organisms or do not directly relate to plant defense strategies.
Plants have evolved various strategies to protect themselves from herbivores, which can cause significant damage. Among the adaptations listed, thorns on Acacia trees serve as a primary example of a plant defense mechanism.
Thorns on Acacia Trees
- Physical Barrier:
Thorns act as a physical deterrent, making it difficult for herbivores to consume the leaves and stems of the tree. This adaptation helps reduce the likelihood of being eaten.
- Predator Attraction:
In some cases, Acacia trees also have mutualistic relationships with ants. The thorns can provide shelter for these ants, which, in return, defend the tree by attacking herbivores.
Other Options Explained
- High Reproductive Rate of a Parasitic Plant:
This adaptation is not a defense mechanism but rather a strategy for survival and dispersal. Parasitic plants rely on host plants for nutrients, not defending themselves from herbivores.
- Chemical Production in Calotropis:
While this adaptation does harm herbivores, it is more of a chemical defense rather than a structural one. It represents a different category of defense mechanisms.
- Camouflage in Insects like the Monarch Butterfly:
This is an adaptation of the insect and does not pertain to plant defenses. It highlights predator evasion rather than plant strategies against herbivores.
Conclusion
In summary, thorns on Acacia trees exemplify physical defenses that discourage herbivores, while the other options either pertain to different organisms or do not directly relate to plant defense strategies.
Statement I: Age pyramid of expanding population is broader at base and thin upwards.
Statement II: Number of individuals in pre-reproductive age is more than post reproductive age.
Statement III: population size is technically called as population density.- a)Only statement II and III are correct.
- b)Only statement I and II are correct.
- c)All statements are correct.
- d)All statements are incorrect.
Correct answer is option 'C'. Can you explain this answer?
Statement I: Age pyramid of expanding population is broader at base and thin upwards.
Statement II: Number of individuals in pre-reproductive age is more than post reproductive age.
Statement III: population size is technically called as population density.
Statement II: Number of individuals in pre-reproductive age is more than post reproductive age.
Statement III: population size is technically called as population density.
a)
Only statement II and III are correct.
b)
Only statement I and II are correct.
c)
All statements are correct.
d)
All statements are incorrect.
|
Prashanth Dasgupta answered |
Age pyramid of expanding population is broader at base and thin upwards. Number of individuals in pre-reproductive age is more than post reproductive age. Population size is technically called as population density.
Mediterranean orchid Ophrysensures pollination by :- a)Pseudocopulation only
- b)Sexual deceit and co-evolution
- c)Brood parasitism
- d)Co-evolution, sexual deceit and pseudo-copulation
Correct answer is option 'D'. Can you explain this answer?
Mediterranean orchid Ophrysensures pollination by :
a)
Pseudocopulation only
b)
Sexual deceit and co-evolution
c)
Brood parasitism
d)
Co-evolution, sexual deceit and pseudo-copulation
|
Yash Saha answered |
Mediterranean orchid Ophrys ensures pollination by co-evolution, sexual deceit and pseudo-copulation. One petal of flower bears an uncanny resemblance to female of bee in size, colour and markings.
What does the carrying capacity (K) of a habitat refer to?- a)The maximum growth rate a population can achieve
- b)The maximum number of individuals an environment can support
- c)The rate of immigration into a population
- d)The total biomass of a population
Correct answer is option 'B'. Can you explain this answer?
a)
The maximum growth rate a population can achieve
b)
The maximum number of individuals an environment can support
c)
The rate of immigration into a population
d)
The total biomass of a population
|
Ambition Institute answered |
Carrying capacity (K) refers to the maximum number of individuals a habitat can support given the available resources. Beyond this limit, the population will stop growing or may even decline due to resource depletion.
Topic in NCERT: Carrying Capacity
Line in NCERT: "In nature, a given habitat has enough resources to support a maximum possible number, beyond which no further growth is possible. Let us call this limit as nature's carrying capacity (K) for that species in that habitat."
An age pyramid with a wide base and narrow top indicates a population that is:- a)Changing
- b)Stable
- c)Declining
- d)Growing rapidly
Correct answer is option 'D'. Can you explain this answer?
An age pyramid with a wide base and narrow top indicates a population that is:
a)
Changing
b)
Stable
c)
Declining
d)
Growing rapidly
|
Akshay Chavan answered |
Age Pyramid
An age pyramid, also known as an age distribution graph or population pyramid, is a graphical representation of the age and sex distribution of a population. The pyramid is divided into male and female populations, with age cohorts represented on the horizontal axis and the percentage of the population represented on the vertical axis.
Interpreting an Age Pyramid
The shape of an age pyramid provides valuable insights into the demographic characteristics of a population. By examining the width of the base and the narrowness of the top, we can determine the growth rate and age structure of the population.
Wide Base
A wide base on an age pyramid indicates a large proportion of young individuals in the population. This suggests a high birth rate and a growing population. The wider the base, the higher the number of children and young adults, indicating a significant proportion of the population is in the reproductive age group.
Narrow Top
A narrow top on an age pyramid indicates a smaller proportion of elderly individuals in the population. This suggests a lower life expectancy and a lower proportion of older adults. A narrow top indicates a lower percentage of the population in the older age groups.
Explanation of the Correct Answer
The correct answer, option 'D' (Growing rapidly), is inferred from the description of an age pyramid with a wide base and narrow top. This pyramid shape indicates a population that has a high birth rate and a large proportion of young individuals. The narrower top suggests a lower life expectancy and a smaller proportion of older individuals.
When a population has a wide base and a narrow top, it indicates that the birth rate is higher than the death rate, leading to a rapid increase in population size. The large number of young individuals suggests a growing population with a high potential for future growth.
Therefore, an age pyramid with a wide base and narrow top indicates a population that is growing rapidly.
An age pyramid, also known as an age distribution graph or population pyramid, is a graphical representation of the age and sex distribution of a population. The pyramid is divided into male and female populations, with age cohorts represented on the horizontal axis and the percentage of the population represented on the vertical axis.
Interpreting an Age Pyramid
The shape of an age pyramid provides valuable insights into the demographic characteristics of a population. By examining the width of the base and the narrowness of the top, we can determine the growth rate and age structure of the population.
Wide Base
A wide base on an age pyramid indicates a large proportion of young individuals in the population. This suggests a high birth rate and a growing population. The wider the base, the higher the number of children and young adults, indicating a significant proportion of the population is in the reproductive age group.
Narrow Top
A narrow top on an age pyramid indicates a smaller proportion of elderly individuals in the population. This suggests a lower life expectancy and a lower proportion of older adults. A narrow top indicates a lower percentage of the population in the older age groups.
Explanation of the Correct Answer
The correct answer, option 'D' (Growing rapidly), is inferred from the description of an age pyramid with a wide base and narrow top. This pyramid shape indicates a population that has a high birth rate and a large proportion of young individuals. The narrower top suggests a lower life expectancy and a smaller proportion of older individuals.
When a population has a wide base and a narrow top, it indicates that the birth rate is higher than the death rate, leading to a rapid increase in population size. The large number of young individuals suggests a growing population with a high potential for future growth.
Therefore, an age pyramid with a wide base and narrow top indicates a population that is growing rapidly.
Which growth pattern occurs when resources become progressively limiting in a population?- a)Logistic growth
- b)Exponential growth
- c)Constant growth
- d)Declining growth
Correct answer is option 'A'. Can you explain this answer?
Which growth pattern occurs when resources become progressively limiting in a population?
a)
Logistic growth
b)
Exponential growth
c)
Constant growth
d)
Declining growth
|
|
Rajesh Gupta answered |
Populations grow through births and immigration and decline through deaths and emigration.
When resources become progressively limiting for a population, the growth pattern turns logistic. This means that initially, the population may experience exponential growth when resources are abundant and unlimited.
However, as resources start to become scarce and limiting, the growth rate of the population slows down and eventually levels off. This pattern is known as logistic growth.
- Exponential growth (option b) refers to a rapid and unrestricted increase in population size without resource limitations.
- Constant growth (option c) implies a steady and consistent growth rate over time, regardless of resource availability.
- Declining growth (option d) suggests a decrease in population size over time, often due to factors like limited resources or environmental disturbances.
The formula for exponential population growth is[2006]- a)dN/rN = dt
- b)rN / dN = dt
- c)dN / dt = rN
- d)dt / dN = rN
Correct answer is option 'C'. Can you explain this answer?
The formula for exponential population growth is
[2006]
a)
dN/rN = dt
b)
rN / dN = dt
c)
dN / dt = rN
d)
dt / dN = rN
|
|
Mrinalini Bajaj answered |
The formula of exponential growth is 
is the rate of change in population size, r is the biotic potential and N is the population size.
is the rate of change in population size, r is the biotic potential and N is the population size.The population of an insect species shows an explosive increase in numbers during rainy season followed by its disappearance at the end of the season. What does this show? [2007]- a)The food plants mature and die at the end of the rainy season
- b)Its population growth curve is of J-type
- c)The population of its predators increases enormously
- d)S-shaped or sigmoid g rowth of this insect.
Correct answer is option 'B'. Can you explain this answer?
The population of an insect species shows an explosive increase in numbers during rainy season followed by its disappearance at the end of the season. What does this show?
[2007]
a)
The food plants mature and die at the end of the rainy season
b)
Its population growth curve is of J-type
c)
The population of its predators increases enormously
d)
S-shaped or sigmoid g rowth of this insect.
|
Maheshwar Saini answered |
If a population (e.g reindeer population) is allowed to grow in a predator free environment, the population grows beyond carrying capacity and there occurs population crash due to sudden shortage of food. Such growth curves also occur in insect populations during rainy season, and in algal blooms.
Consider the following statements about population growth and dynamics:
1. Exponential growth occurs only when resources are limited.
2. Logistic growth models show a sigmoid curve and account for carrying capacity.
3. Natality, mortality, immigration, and emigration are the four main factors that influence population size.
4. The intrinsic rate of natural increase (r) is constant and unaffected by environmental conditions.
Which of the following options is correct?- a)Statements 1 and 4 are correct.
- b)Statements 2 and 3 are correct.
- c)Statements 1 and 3 are correct.
- d)All statements are correct.
Correct answer is option 'B'. Can you explain this answer?
Consider the following statements about population growth and dynamics:
1. Exponential growth occurs only when resources are limited.
2. Logistic growth models show a sigmoid curve and account for carrying capacity.
3. Natality, mortality, immigration, and emigration are the four main factors that influence population size.
4. The intrinsic rate of natural increase (r) is constant and unaffected by environmental conditions.
Which of the following options is correct?
1. Exponential growth occurs only when resources are limited.
2. Logistic growth models show a sigmoid curve and account for carrying capacity.
3. Natality, mortality, immigration, and emigration are the four main factors that influence population size.
4. The intrinsic rate of natural increase (r) is constant and unaffected by environmental conditions.
Which of the following options is correct?
a)
Statements 1 and 4 are correct.
b)
Statements 2 and 3 are correct.
c)
Statements 1 and 3 are correct.
d)
All statements are correct.
|
Jay Chaudhary answered |
Understanding Population Growth Dynamics
Population dynamics is a crucial field of study in ecology, focusing on how populations change over time. Let's evaluate the given statements:
1. Exponential Growth and Resource Limitations
- Incorrect Statement: Exponential growth occurs when resources are abundant, allowing populations to grow rapidly without constraints. It does not occur only when resources are limited.
2. Logistic Growth and Carrying Capacity
- Correct Statement: Logistic growth is characterized by a sigmoid curve, which illustrates how a population grows rapidly at first, then slows as it approaches the carrying capacity of the environment. This model effectively integrates the concept of environmental limitations.
3. Factors Influencing Population Size
- Correct Statement: Natality (birth rate), mortality (death rate), immigration (movement into a population), and emigration (movement out of a population) are indeed the primary factors that influence population size, making this statement accurate.
4. Intrinsic Rate of Natural Increase (r)
- Incorrect Statement: The intrinsic rate of natural increase (r) is not constant; it can vary based on environmental conditions, resource availability, and other ecological factors.
Conclusion
Based on the evaluation:
- Statements 2 and 3 are correct, while statements 1 and 4 are incorrect. Thus, the correct answer is option B: "Statements 2 and 3 are correct."
Understanding these principles is essential for grasping how populations grow and interact with their environments, which is a key aspect of ecological studies in NEET.
Population dynamics is a crucial field of study in ecology, focusing on how populations change over time. Let's evaluate the given statements:
1. Exponential Growth and Resource Limitations
- Incorrect Statement: Exponential growth occurs when resources are abundant, allowing populations to grow rapidly without constraints. It does not occur only when resources are limited.
2. Logistic Growth and Carrying Capacity
- Correct Statement: Logistic growth is characterized by a sigmoid curve, which illustrates how a population grows rapidly at first, then slows as it approaches the carrying capacity of the environment. This model effectively integrates the concept of environmental limitations.
3. Factors Influencing Population Size
- Correct Statement: Natality (birth rate), mortality (death rate), immigration (movement into a population), and emigration (movement out of a population) are indeed the primary factors that influence population size, making this statement accurate.
4. Intrinsic Rate of Natural Increase (r)
- Incorrect Statement: The intrinsic rate of natural increase (r) is not constant; it can vary based on environmental conditions, resource availability, and other ecological factors.
Conclusion
Based on the evaluation:
- Statements 2 and 3 are correct, while statements 1 and 4 are incorrect. Thus, the correct answer is option B: "Statements 2 and 3 are correct."
Understanding these principles is essential for grasping how populations grow and interact with their environments, which is a key aspect of ecological studies in NEET.
Which of the following best explains why logistic growth occurs in populations?- a)Populations grow exponentially when resources are unlimited and then decrease rapidly due to the depletion of resources.
- b)Populations grow exponentially but reach a plateau when resources become limited, as determined by the environment's carrying capacity.
- c)Populations exhibit exponential growth indefinitely because they always have sufficient resources.
- d)Populations decline due to environmental factors without any increase in population size.
Correct answer is option 'B'. Can you explain this answer?
a)
Populations grow exponentially when resources are unlimited and then decrease rapidly due to the depletion of resources.
b)
Populations grow exponentially but reach a plateau when resources become limited, as determined by the environment's carrying capacity.
c)
Populations exhibit exponential growth indefinitely because they always have sufficient resources.
d)
Populations decline due to environmental factors without any increase in population size.
|
Lead Academy answered |
Logistic growth occurs when populations experience exponential growth under ideal conditions but eventually slow down and level off as resources become limited. The population size stabilizes around the environment's carrying capacity, where growth is regulated by factors like food availability, space, and other ecological constraints.
Which of the following are examples of parasitism?- a) interaction between sea anemone that has stinging tentacles and the clown fish
- b)The Monarch butterfly’s chemical defenses.
- c)A lichen growing on a tree branch.
- d)The human liver fluke’s life cycle involving two intermediate hosts.
Correct answer is option 'D'. Can you explain this answer?
Which of the following are examples of parasitism?
a)
interaction between sea anemone that has stinging tentacles and the clown fish
b)
The Monarch butterfly’s chemical defenses.
c)
A lichen growing on a tree branch.
d)
The human liver fluke’s life cycle involving two intermediate hosts.
|
Bs Academy answered |
the human liver fluke’s life cycle (D) is an example of parasitism, where one species benefits at the expense of another. The other options describe mutualistic or commensal relationships.
Topic in NCERT: Life Cycles of Parasites
Line in NCERT: "The human liver fluke (a trematode parasite) depends on two intermediate hosts (a snail and a fish) to complete its life cycle."
Which of the following factors is most ecologically relevant to living organisms, affecting their metabolism, activity, and physiological functions?- a)Water availability
- b)Temperature
- c)Soil composition
- d)Light intensity
Correct answer is option 'B'. Can you explain this answer?
a)
Water availability
b)
Temperature
c)
Soil composition
d)
Light intensity
|
|
Gayatri Desai answered |
Understanding the Relevance of Temperature to Living Organisms
Temperature plays a crucial role in the ecological functioning of living organisms. It directly influences their metabolism, activity levels, and overall physiological processes. Here’s a detailed look at why temperature is paramount:
1. Metabolic Rate
- Temperature significantly affects the metabolic rates of organisms.
- Most biochemical reactions in living cells are temperature-dependent; as temperature increases, reaction rates typically increase as well, up to an optimum level.
2. Enzymatic Activity
- Enzymes, which are vital for metabolic processes, have specific temperature ranges for optimal activity.
- Deviations from this range can lead to reduced efficiency or even denaturation of enzymes, severely impacting metabolism.
3. Physiological Functions
- Temperature influences physiological functions such as respiration, digestion, and reproduction.
- For example, ectothermic (cold-blooded) animals rely on external temperatures to regulate their body heat, affecting their activity levels.
4. Species Distribution
- Temperature affects the geographic distribution of species.
- Organisms have adapted to specific temperature ranges, and changes in climate can lead to shifts in habitat availability.
5. Interactions Within Ecosystems
- Temperature influences not only individual organisms but also their interactions within ecosystems.
- It impacts predator-prey dynamics, competition, and species relationships.
In summary, while factors like water availability, soil composition, and light intensity are important, temperature is the most ecologically relevant factor affecting the fundamental physiological and metabolic processes of living organisms.
Temperature plays a crucial role in the ecological functioning of living organisms. It directly influences their metabolism, activity levels, and overall physiological processes. Here’s a detailed look at why temperature is paramount:
1. Metabolic Rate
- Temperature significantly affects the metabolic rates of organisms.
- Most biochemical reactions in living cells are temperature-dependent; as temperature increases, reaction rates typically increase as well, up to an optimum level.
2. Enzymatic Activity
- Enzymes, which are vital for metabolic processes, have specific temperature ranges for optimal activity.
- Deviations from this range can lead to reduced efficiency or even denaturation of enzymes, severely impacting metabolism.
3. Physiological Functions
- Temperature influences physiological functions such as respiration, digestion, and reproduction.
- For example, ectothermic (cold-blooded) animals rely on external temperatures to regulate their body heat, affecting their activity levels.
4. Species Distribution
- Temperature affects the geographic distribution of species.
- Organisms have adapted to specific temperature ranges, and changes in climate can lead to shifts in habitat availability.
5. Interactions Within Ecosystems
- Temperature influences not only individual organisms but also their interactions within ecosystems.
- It impacts predator-prey dynamics, competition, and species relationships.
In summary, while factors like water availability, soil composition, and light intensity are important, temperature is the most ecologically relevant factor affecting the fundamental physiological and metabolic processes of living organisms.
Choose the correct sequence of stages of growth curve for bacteria[2002]- a)Lag, log, stationary, decline phase
- b)Lag, log, stationary phase
- c)Stationary, lag, log, decline phase
- d)Decline, lag, log phase
Correct answer is option 'A'. Can you explain this answer?
Choose the correct sequence of stages of growth curve for bacteria
[2002]
a)
Lag, log, stationary, decline phase
b)
Lag, log, stationary phase
c)
Stationary, lag, log, decline phase
d)
Decline, lag, log phase
|
Dipika Das answered |
The growth curve for bacteria is sigmoid. First phase is the phase of slow growth- Lag phase. Second phase is the period of accelerated growth - Log phase. Third phase is the phase when growth rate becomes stable - Stationary phase. Finally growth rate declines.
Inspite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival? [2021]- a)Mutualism
- b)Predation
- c)Resource partitioning
- d)Competitive release
Correct answer is option 'C'. Can you explain this answer?
Inspite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival? [2021]
a)
Mutualism
b)
Predation
c)
Resource partitioning
d)
Competitive release
|
|
Dev Patel answered |
While they do not rule out the occurrence of interspecific competition in nature, they point out that species facing competition might evolve mechanisms that promote co-existence rather than exclusion. One such mechanism is ‘resource partitioning’.
Q1: Given below are two statements: (NEET 2024)
Statement I : Gause’s ‘Competitive Exclusion Principle’ states that two closely related species competing for the same resources cannot co-exist indefinitely and competitively inferior one will be eliminated eventually.
Statement II : In general, carnivores are more adversely affected by competition than herbivores.
In the light of the above statements, choose the correct answer from the options given below:- a)Both Statement I and Statement II are true.
- b)Both Statement I and Statement II are false.
- c)Statement I is correct Statement II is false.
- d)Statement I is incorrect but Statement II is true.
Correct answer is option 'C'. Can you explain this answer?
Q1: Given below are two statements: (NEET 2024)
Statement I : Gause’s ‘Competitive Exclusion Principle’ states that two closely related species competing for the same resources cannot co-exist indefinitely and competitively inferior one will be eliminated eventually.
Statement II : In general, carnivores are more adversely affected by competition than herbivores.
In the light of the above statements, choose the correct answer from the options given below:
Statement I : Gause’s ‘Competitive Exclusion Principle’ states that two closely related species competing for the same resources cannot co-exist indefinitely and competitively inferior one will be eliminated eventually.
Statement II : In general, carnivores are more adversely affected by competition than herbivores.
In the light of the above statements, choose the correct answer from the options given below:
a)
Both Statement I and Statement II are true.
b)
Both Statement I and Statement II are false.
c)
Statement I is correct Statement II is false.
d)
Statement I is incorrect but Statement II is true.
|
Stepway Academy answered |
Gause's 'Competitive Exclusion Principle' states that two closely related species competing for the same resources cannot co-exist indefinitely and the competitively inferior one will be eliminated eventaully. Thus, statement I is correct.
Statement II is incorrect as in general, herbivores and plants appear to be more adversely affected by competition than carnivores.
Statement II is incorrect as in general, herbivores and plants appear to be more adversely affected by competition than carnivores.
Geometric representation of age structure is a characteristic of[2007]- a)population
- b)landscape
- c)ecosystem
- d)biotic community.
Correct answer is option 'A'. Can you explain this answer?
Geometric representation of age structure is a characteristic of
[2007]
a)
population
b)
landscape
c)
ecosystem
d)
biotic community.
|
|
Charvi Shah answered |
Geometric representation of age structure a characteristic of population.
In which one of the following habitats does the diurnal temperature of soil surface vary most?[2004]- a)Shrub land
- b)Forest
- c)Desert
- d)Grassland
Correct answer is option 'C'. Can you explain this answer?
In which one of the following habitats does the diurnal temperature of soil surface vary most?
[2004]
a)
Shrub land
b)
Forest
c)
Desert
d)
Grassland
|
Pooja Saha answered |
Desert show maximum difference between day and night temperature.
Which type of interaction benefits both species involved?- a)Competition
- b)Predation
- c)Mutualism
- d)Parasitism
Correct answer is option 'C'. Can you explain this answer?
Which type of interaction benefits both species involved?
a)
Competition
b)
Predation
c)
Mutualism
d)
Parasitism
|
|
Rajesh Gupta answered |
Interactions between species can have different outcomes. In mutualism, both species benefit from the interaction. This means that there is a mutually beneficial relationship where both species gain advantages, such as access to food, protection, or reproductive assistance.
Option d) Mutualism is the correct answer because it accurately identifies the type of interaction where both species involved benefit from each other.
Chapter doubts & questions for Organisms and Populations - 4 Months Preparation for NEET 2025 is part of NEET exam preparation. The chapters have been prepared according to the NEET exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for NEET 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
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