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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.
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.
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.
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
|
Rohan Unni 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.
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.
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 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.
|
Infinity Academy answered |
Thorns on Acacia trees (A) and chemical production in Calotropis (C) are direct plant defenses against herbivores. The other options do not describe plant adaptations.
Topic in NCERT: Defenses Against Herbivory
Line in NCERT: "Plants therefore have evolved an astonishing variety of morphological and chemical defences against herbivores. Thorns (Acacia, Cactus) are the most common morphological means of defence. Many plants produce and store chemicals that make the herbivore sick when they are eaten, inhibit feeding or digestion, disrupt its reproduction or even kill it."
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
|
|
Abhijeet Sengupta answered |
Understanding Carrying Capacity (K)
The carrying capacity, often denoted as "K," is a crucial ecological concept that defines the limits of a habitat's ability to sustain a population. Here's a detailed explanation:
Definition of Carrying Capacity
- The carrying capacity refers to the maximum number of individuals of a particular species that an environment can support over time without degrading the habitat.
- It is influenced by various factors such as food availability, water supply, habitat space, and the presence of predators and diseases.
Importance of Carrying Capacity
- Understanding carrying capacity helps in the management of wildlife populations and natural resources, ensuring that ecosystems remain balanced and healthy.
- It aids in predicting how changes in the environment (like climate change or human encroachment) can impact species survival.
Factors Influencing Carrying Capacity
- Resource Availability: The amount of food, water, and shelter available directly affects how many individuals can be supported.
- Environmental Conditions: Changes in climate, habitat destruction, and pollution can lower the carrying capacity.
- Species Interactions: Predation, competition, and disease can either increase or decrease the effective carrying capacity.
Consequences of Exceeding Carrying Capacity
- When a population exceeds its carrying capacity, it can lead to overpopulation, resulting in resource depletion, habitat destruction, and a decline in population health.
- This often causes a population crash, where the numbers plummet due to starvation or increased mortality.
In summary, the carrying capacity (K) is essential for maintaining ecological balance, and understanding it allows for better conservation and management strategies.
The carrying capacity, often denoted as "K," is a crucial ecological concept that defines the limits of a habitat's ability to sustain a population. Here's a detailed explanation:
Definition of Carrying Capacity
- The carrying capacity refers to the maximum number of individuals of a particular species that an environment can support over time without degrading the habitat.
- It is influenced by various factors such as food availability, water supply, habitat space, and the presence of predators and diseases.
Importance of Carrying Capacity
- Understanding carrying capacity helps in the management of wildlife populations and natural resources, ensuring that ecosystems remain balanced and healthy.
- It aids in predicting how changes in the environment (like climate change or human encroachment) can impact species survival.
Factors Influencing Carrying Capacity
- Resource Availability: The amount of food, water, and shelter available directly affects how many individuals can be supported.
- Environmental Conditions: Changes in climate, habitat destruction, and pollution can lower the carrying capacity.
- Species Interactions: Predation, competition, and disease can either increase or decrease the effective carrying capacity.
Consequences of Exceeding Carrying Capacity
- When a population exceeds its carrying capacity, it can lead to overpopulation, resulting in resource depletion, habitat destruction, and a decline in population health.
- This often causes a population crash, where the numbers plummet due to starvation or increased mortality.
In summary, the carrying capacity (K) is essential for maintaining ecological balance, and understanding it allows for better conservation and management strategies.
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
|
|
Rajesh Gupta answered |
An age pyramid with a wide base and narrow top indicates a population that is growing rapidly.
In an age pyramid, the width of each age group represents the proportion or percentage of individuals in that specific age group. A wide base indicates a larger population of young individuals, while a narrow top indicates a smaller population of older individuals.
When the base of an age pyramid is wide and the subsequent age groups gradually decrease in width towards the top, it suggests that there is a higher proportion of young individuals compared to older individuals. This is indicative of a population that is growing rapidly because there is a high birth rate.
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
|
|
Tarun Saha answered |
Logistic growth
Logistic growth is a growth pattern that occurs when resources become progressively limiting in a population. It is a more realistic model of population growth compared to exponential growth, which does not take into account the carrying capacity of an environment.
Understanding logistic growth
Logistic growth is characterized by an initial exponential increase in population size, followed by a slowing down of growth as resources become limited. This is because as a population grows, it will eventually reach a point where there are not enough resources (such as food, water, and shelter) to support further growth.
Factors affecting logistic growth
Several factors influence the occurrence of logistic growth in a population:
1. Carrying capacity: The carrying capacity is the maximum number of individuals that an environment can sustainably support. As a population reaches this limit, resources become increasingly scarce, causing growth to slow down.
2. Density-dependent factors: These are factors that have a greater impact on population growth as population density increases. Examples include competition for resources, predation, and disease. As population density increases due to exponential growth, these factors become more significant in limiting growth.
3. Birth and death rates: In a logistic growth model, birth rates initially exceed death rates, leading to exponential growth. However, as resources become limiting, birth rates start to decline, and death rates may increase due to increased competition and reduced access to resources.
Graphical representation
Logistic growth is often represented graphically using an S-shaped curve. In the initial phase, the curve rises steeply, representing exponential growth. As the population approaches the carrying capacity, the curve levels off and reaches a plateau, indicating the slowing down of growth. At the carrying capacity, the population stabilizes and remains relatively constant.
Significance of logistic growth
Understanding logistic growth is crucial in ecology and population biology. It helps us predict and manage populations, determine the impacts of resource availability on population dynamics, and assess the sustainability of ecosystems. By considering the carrying capacity and the factors that influence population growth, we can make more accurate predictions and develop effective conservation and management strategies.
Logistic growth is a growth pattern that occurs when resources become progressively limiting in a population. It is a more realistic model of population growth compared to exponential growth, which does not take into account the carrying capacity of an environment.
Understanding logistic growth
Logistic growth is characterized by an initial exponential increase in population size, followed by a slowing down of growth as resources become limited. This is because as a population grows, it will eventually reach a point where there are not enough resources (such as food, water, and shelter) to support further growth.
Factors affecting logistic growth
Several factors influence the occurrence of logistic growth in a population:
1. Carrying capacity: The carrying capacity is the maximum number of individuals that an environment can sustainably support. As a population reaches this limit, resources become increasingly scarce, causing growth to slow down.
2. Density-dependent factors: These are factors that have a greater impact on population growth as population density increases. Examples include competition for resources, predation, and disease. As population density increases due to exponential growth, these factors become more significant in limiting growth.
3. Birth and death rates: In a logistic growth model, birth rates initially exceed death rates, leading to exponential growth. However, as resources become limiting, birth rates start to decline, and death rates may increase due to increased competition and reduced access to resources.
Graphical representation
Logistic growth is often represented graphically using an S-shaped curve. In the initial phase, the curve rises steeply, representing exponential growth. As the population approaches the carrying capacity, the curve levels off and reaches a plateau, indicating the slowing down of growth. At the carrying capacity, the population stabilizes and remains relatively constant.
Significance of logistic growth
Understanding logistic growth is crucial in ecology and population biology. It helps us predict and manage populations, determine the impacts of resource availability on population dynamics, and assess the sustainability of ecosystems. By considering the carrying capacity and the factors that influence population growth, we can make more accurate predictions and develop effective conservation and management strategies.
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.
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
|
Hridoy Mehta answered |
Mutualism
Mutualism is a type of interaction between two species in which both species benefit from the relationship. This type of interaction is considered to be mutually beneficial and can occur in a variety of ecosystems and between different types of organisms.
Definition of Mutualism
Mutualism is a form of symbiotic relationship where both species involved benefit from the interaction. It is a cooperative interaction that enhances the survival, growth, and reproduction of both species.
Examples of Mutualism
There are numerous examples of mutualism in nature, demonstrating the wide range of organisms that can engage in this type of interaction. Here are a few examples:
- Pollination: Bees and flowers have a mutualistic relationship. Bees obtain nectar from flowers, which provides them with a food source, while flowers benefit from the transfer of pollen from one flower to another, facilitating reproduction.
- Cleaner Fish and Host Fish: Cleaner fish, such as cleaner wrasses, remove parasites and dead skin from host fish. The cleaner fish benefits by obtaining food, while the host fish benefits from the removal of parasites, improving its health and well-being.
- Leafcutter Ants and Fungus: Leafcutter ants cultivate fungus gardens by cutting and transporting leaves. The ants feed on the fungus, while the fungus benefits from the constant supply of organic matter and protection provided by the ants.
Benefits of Mutualism
Mutualism is advantageous for both species involved due to the following reasons:
- Resource Sharing: Both species share resources, such as food, shelter, or protection, which increases their chances of survival and reproduction.
- Increased Fitness: By working together, both species can increase their overall fitness and reproductive success. This can lead to population growth and long-term survival.
- Enhanced Nutrient Cycling: Mutualistic relationships can improve nutrient cycling in ecosystems, benefiting the overall health and productivity of the environment.
Conclusion
Mutualism is a type of interaction that benefits both species involved. It is a cooperative relationship that enhances survival, growth, and reproduction. Examples of mutualism can be found in various ecosystems, demonstrating the importance of this type of interaction in nature.
When one population is harmed and the other remains unaffected, the relationship is called- a)Protocooperation
- b)Predation
- c)Amensalism
- d)Parasitism
Correct answer is option 'C'. Can you explain this answer?
When one population is harmed and the other remains unaffected, the relationship is called
a)
Protocooperation
b)
Predation
c)
Amensalism
d)
Parasitism
|
|
Dev Kumar answered |
No,It would be amensalism only when one population is being harmed by other population unconditionally means there is no intention of the population to harm the other population but it occurs due to release of some toxic substances by the population which harms the other population unintentionally and the population releasing toxic substances remains unharmed.
but Accord to your question ans can also be predation and parasitism.
How does a carnivore population increase?- a)Due to the decrease in the availability of grass
- b)Due to the increase in the population of omnivore
- c)Due to the increase in the population of scavenger
- d)Due to the increase in the population of herbivore
Correct answer is option 'D'. Can you explain this answer?
How does a carnivore population increase?
a)
Due to the decrease in the availability of grass
b)
Due to the increase in the population of omnivore
c)
Due to the increase in the population of scavenger
d)
Due to the increase in the population of herbivore
|
Mohit Rajpoot answered |
A carnivore population increases due to an increase in the population of herbivores. In this, an organism i.e. carnivore (predator) is benefited by killing and eating another organism i.e. herbivore (prey).
Which of the following statements are correct?
(i) Organisms with high reproductive rates (r value) evolve to maximize their reproductive fitness.
(ii) Organisms that breed only once in their lifetime are more likely to have large offspring.
(iii) The evolution of life history traits is unaffected by the constraints of the habitat.
(iv) Different species evolve life history traits based on both biotic and abiotic factors of their environment.- a) Only 1 and 4
- b)Only 2 and 3
- c)Only 1 and 2
- d)Only 3 and 4
Correct answer is option 'A'. Can you explain this answer?
Which of the following statements are correct?
(i) Organisms with high reproductive rates (r value) evolve to maximize their reproductive fitness.
(ii) Organisms that breed only once in their lifetime are more likely to have large offspring.
(iii) The evolution of life history traits is unaffected by the constraints of the habitat.
(iv) Different species evolve life history traits based on both biotic and abiotic factors of their environment.
(i) Organisms with high reproductive rates (r value) evolve to maximize their reproductive fitness.
(ii) Organisms that breed only once in their lifetime are more likely to have large offspring.
(iii) The evolution of life history traits is unaffected by the constraints of the habitat.
(iv) Different species evolve life history traits based on both biotic and abiotic factors of their environment.
a)
Only 1 and 4
b)
Only 2 and 3
c)
Only 1 and 2
d)
Only 3 and 4
|
EduRev NEET answered |
Statement A is correct. Organisms with high reproductive rates (high r value) evolve to maximize their reproductive fitness by increasing their population size rapidly.
Statement B is incorrect. Organisms that breed only once in their lifetime, such as Pacific salmon, typically produce many small offspring, not large ones.
Statement C is incorrect. Life history traits are shaped by both biotic (living) and abiotic (non-living) factors in the environment, which constrain and influence their evolution.
Statement D is correct. The evolution of life history traits is heavily influenced by the abiotic and biotic components of the organism's habitat, ensuring that the traits align with environmental conditions.
Therefore, the correct answer is Option A and Option D are correct.
Statement B is incorrect. Organisms that breed only once in their lifetime, such as Pacific salmon, typically produce many small offspring, not large ones.
Statement C is incorrect. Life history traits are shaped by both biotic (living) and abiotic (non-living) factors in the environment, which constrain and influence their evolution.
Statement D is correct. The evolution of life history traits is heavily influenced by the abiotic and biotic components of the organism's habitat, ensuring that the traits align with environmental conditions.
Therefore, the correct answer is Option A and Option D are correct.
Topic in NCERT: Life History Variation
Line in NCERT: "Populations evolve to maximise their reproductive fitness, also called Darwinian fitness (high r value), in the habitat in which they live."
The plants of this group are adapted to live partly in water and partly above substratum and free from water:- a)Xerophytes
- b)Thallophytes
- c)Hydrophytes
- d)Helophytes
Correct answer is option 'D'. Can you explain this answer?
The plants of this group are adapted to live partly in water and partly above substratum and free from water:
a)
Xerophytes
b)
Thallophytes
c)
Hydrophytes
d)
Helophytes
|
Stepway Academy answered |
- A helophyte is a plant that grows in marsh, partly submerged in water, so that it regrows from buds below the water surface.
- Fringing stands of tall vegetation by water basins and rivers may include helophytes.
- Examples include stands of Equisetum fluviatile, Glyceria maxima, Hippuris vulgaris, Sagittaria, Carex, Schoenoplectus, Sparganium, Acorus, Yellow flag, etc.
Which of the following groups will be able thrive in hypersaline lagoons?- a)Eurythermal species
- b)Stenothermal species
- c)Stenohaline species
- d)Euryhaline species
Correct answer is option 'D'. Can you explain this answer?
Which of the following groups will be able thrive in hypersaline lagoons?
a)
Eurythermal species
b)
Stenothermal species
c)
Stenohaline species
d)
Euryhaline species
|
|
Rajesh Datta answered |
Hypersaline lagoons have very high concentration of salt (>100). Some organisms can survive in wide range of salinity. These organisms are calledeuryhaline species.
Which should be considered more realistic growth model?- a)Verhulst-Pearl logistic growth
- b)Geometric growth
- c)Exponential growth
- d)None of these
Correct answer is option 'A'. Can you explain this answer?
Which should be considered more realistic growth model?
a)
Verhulst-Pearl logistic growth
b)
Geometric growth
c)
Exponential growth
d)
None of these
|
|
Prashanth Dasgupta answered |
Verhulst-Pearl logistic model of growth is more realistic growth model in comparison to exponential model of growth. Population growing in a habitat having limited resources shows sigmoid curve like growth before reaching to carrying capacity.
Which type of interaction does a mycorrhiza show?- a)Predation
- b)Parasitism
- c)Commensalism
- d)Mutualism
Correct answer is option 'D'. Can you explain this answer?
Which type of interaction does a mycorrhiza show?
a)
Predation
b)
Parasitism
c)
Commensalism
d)
Mutualism
|
|
Dhruba Patel answered |
Explanation:
Mychorrhiza is a type of mutualistic relationship between a fungus and the roots of a plant. This interaction is beneficial for both parties involved, as they each provide something the other needs.
Mutualism:
- In a mycorrhizal relationship, the fungus helps the plant absorb nutrients such as phosphorus and nitrogen from the soil.
- In return, the plant provides the fungus with sugars produced through photosynthesis.
This mutualistic interaction is essential for the health and growth of many plant species, as it allows them to access nutrients that would otherwise be difficult to obtain. Mycorrhizae are found in a wide range of plant species and are crucial for the functioning of many ecosystems.
Mychorrhiza is a type of mutualistic relationship between a fungus and the roots of a plant. This interaction is beneficial for both parties involved, as they each provide something the other needs.
Mutualism:
- In a mycorrhizal relationship, the fungus helps the plant absorb nutrients such as phosphorus and nitrogen from the soil.
- In return, the plant provides the fungus with sugars produced through photosynthesis.
This mutualistic interaction is essential for the health and growth of many plant species, as it allows them to access nutrients that would otherwise be difficult to obtain. Mycorrhizae are found in a wide range of plant species and are crucial for the functioning of many ecosystems.
In which phase is the stationary phase absent?- a)Sigmoidal growth
- b)Exponential growth
- c)Decreasing growth
- d)Deacceleration growth
Correct answer is option 'B'. Can you explain this answer?
In which phase is the stationary phase absent?
a)
Sigmoidal growth
b)
Exponential growth
c)
Decreasing growth
d)
Deacceleration growth
|
|
Aditi Singh answered |
Understanding Growth Phases in Microbiology
In microbial growth, organisms typically go through several distinct phases: lag, exponential (log), stationary, and death. Each phase represents a different stage in population dynamics.
Exponential Growth Phase
- The exponential growth phase is characterized by rapid cell division and population increase.
- During this phase, the rate of growth is constant, leading to a doubling of the population at regular intervals.
Absence of Stationary Phase
- In the exponential phase, the conditions are ideal: nutrients are abundant, and waste products are minimal.
- Because of these optimal conditions, the growth rate continues to accelerate without any slowdown; therefore, the stationary phase does not occur in this phase.
Other Growth Phases
- Sigmoidal Growth: This phase includes lag, exponential, stationary, and death phases. The stationary phase emerges as resources are depleted.
- Decreasing Growth: As nutrients diminish, growth slows down, leading to the stationary and eventually death phase.
- Deacceleration Growth: This phase indicates a slowdown in growth but is still above the death phase, often transitioning towards stationary.
Conclusion
In summary, during the exponential growth phase, the population grows at its maximum rate due to favorable conditions, which results in the absence of the stationary phase. The understanding of these growth phases is crucial for studies in microbiology and biotechnology, particularly in applications like fermentation and antibiotic production.
In microbial growth, organisms typically go through several distinct phases: lag, exponential (log), stationary, and death. Each phase represents a different stage in population dynamics.
Exponential Growth Phase
- The exponential growth phase is characterized by rapid cell division and population increase.
- During this phase, the rate of growth is constant, leading to a doubling of the population at regular intervals.
Absence of Stationary Phase
- In the exponential phase, the conditions are ideal: nutrients are abundant, and waste products are minimal.
- Because of these optimal conditions, the growth rate continues to accelerate without any slowdown; therefore, the stationary phase does not occur in this phase.
Other Growth Phases
- Sigmoidal Growth: This phase includes lag, exponential, stationary, and death phases. The stationary phase emerges as resources are depleted.
- Decreasing Growth: As nutrients diminish, growth slows down, leading to the stationary and eventually death phase.
- Deacceleration Growth: This phase indicates a slowdown in growth but is still above the death phase, often transitioning towards stationary.
Conclusion
In summary, during the exponential growth phase, the population grows at its maximum rate due to favorable conditions, which results in the absence of the stationary phase. The understanding of these growth phases is crucial for studies in microbiology and biotechnology, particularly in applications like fermentation and antibiotic production.
Which of the following statements about predation is correct?- a)Predation is a form of mutualism where both predator and prey benefit.
- b)Predators can prevent prey populations from achieving high densities.
- c)Herbivores are not considered predators in ecological terms.
- d)Overexploitation of prey by predators leads to the extinction of both predator and prey species.
Correct answer is option 'B'. Can you explain this answer?
a)
Predation is a form of mutualism where both predator and prey benefit.
b)
Predators can prevent prey populations from achieving high densities.
c)
Herbivores are not considered predators in ecological terms.
d)
Overexploitation of prey by predators leads to the extinction of both predator and prey species.
|
|
Bs Academy answered |
Predators help control prey populations, often preventing prey from reaching excessively high densities. This is a natural ecological balance.
Topic in NCERT: Predation and its Ecological Role
Line in NCERT: "Some predators help in controlling their prey populations."
What is 'resource partitioning' and how does it help species co-exist?- a)It refers to species dividing resources like food or space to reduce competition.
- b)It is a process where one species eliminates another due to competitive superiority.
- c)It enables species to share the same habitat without harm.
- d)It allows species to access the same resource at different times or in different ways.
Correct answer is option 'A'. Can you explain this answer?
a)
It refers to species dividing resources like food or space to reduce competition.
b)
It is a process where one species eliminates another due to competitive superiority.
c)
It enables species to share the same habitat without harm.
d)
It allows species to access the same resource at different times or in different ways.
|
Ambition Institute answered |
Resource partitioning is a strategy where species share the same resources but divide them in a way that reduces competition, allowing them to coexist. This can be through spatial or temporal division of resources.
Topic in NCERT: Competition and Co-existence
Line in NCERT: "One such mechanism is ‘resource partitioning'. If two species compete for the same resource, they could avoid competition by choosing, for instance, different times for feeding or different foraging patterns."
The rate of individuals born per 1,000 individuals per year is called- a)Mortality rate
- b)Growth rate
- c)Vital rate
- d)Natality rate
Correct answer is option 'D'. Can you explain this answer?
The rate of individuals born per 1,000 individuals per year is called
a)
Mortality rate
b)
Growth rate
c)
Vital rate
d)
Natality rate
|
Shivani Dasgupta answered |
Natality Rate
Natality rate refers to the number of individuals born per 1,000 individuals per year in a population. It is also known as the birth rate. This rate is an important demographic factor that helps to understand the growth and dynamics of a population.
Calculation of Natality Rate
Natality rate is calculated by dividing the number of live births in a year by the total population of the area or region and then multiplying it by 1,000. The formula to calculate the natality rate is:
Natality Rate = (Number of Live Births / Total Population) x 1,000
For example, if a region has a population of 100,000 and 2,000 babies are born in a year, the natality rate can be calculated as:
Natality Rate = (2,000 / 100,000) x 1,000 = 20 births per 1,000 individuals per year.
Importance of Natality Rate
Natality rate is an important demographic factor that helps to understand the growth and dynamics of a population. It provides information about the reproductive behavior of a population and the number of individuals who are being added to the population every year. Some of the key importance of the natality rate are:
- It helps in understanding the population growth rate, which is the difference between the birth rate and the death rate.
- It is an important indicator of the health and well-being of a population, as it reflects the level of access to healthcare and the prevalence of diseases.
- It is an essential factor in the development of policies and programs related to healthcare, education, and social welfare.
Conclusion
Natality rate is an important demographic factor that helps to understand the growth and dynamics of a population. It is calculated by dividing the number of live births in a year by the total population of the area or region and then multiplying it by 1,000. Understanding the natality rate is essential for policymakers and researchers to develop programs and policies related to healthcare, education, and social welfare.
Natality rate refers to the number of individuals born per 1,000 individuals per year in a population. It is also known as the birth rate. This rate is an important demographic factor that helps to understand the growth and dynamics of a population.
Calculation of Natality Rate
Natality rate is calculated by dividing the number of live births in a year by the total population of the area or region and then multiplying it by 1,000. The formula to calculate the natality rate is:
Natality Rate = (Number of Live Births / Total Population) x 1,000
For example, if a region has a population of 100,000 and 2,000 babies are born in a year, the natality rate can be calculated as:
Natality Rate = (2,000 / 100,000) x 1,000 = 20 births per 1,000 individuals per year.
Importance of Natality Rate
Natality rate is an important demographic factor that helps to understand the growth and dynamics of a population. It provides information about the reproductive behavior of a population and the number of individuals who are being added to the population every year. Some of the key importance of the natality rate are:
- It helps in understanding the population growth rate, which is the difference between the birth rate and the death rate.
- It is an important indicator of the health and well-being of a population, as it reflects the level of access to healthcare and the prevalence of diseases.
- It is an essential factor in the development of policies and programs related to healthcare, education, and social welfare.
Conclusion
Natality rate is an important demographic factor that helps to understand the growth and dynamics of a population. It is calculated by dividing the number of live births in a year by the total population of the area or region and then multiplying it by 1,000. Understanding the natality rate is essential for policymakers and researchers to develop programs and policies related to healthcare, education, and social welfare.
Which of the following should not be characteristic feature of any xerophytes?- a)leaves reduced into spines
- b)absence of the cuticle
- c)sunken stomata
- d)CAM
Correct answer is option 'B'. Can you explain this answer?
Which of the following should not be characteristic feature of any xerophytes?
a)
leaves reduced into spines
b)
absence of the cuticle
c)
sunken stomata
d)
CAM
|
|
Yash Saha answered |
Xerophytes are plants that grows in deserts having very less water. Sunken stomata, leaves reduced into spines and CAM photosysnthesis are the characteristicfeatures of these plants. Cuticle is present on leaves to prevent loss of water.
When the number of immigration and births is more than emigration and deaths, the growth curve of the population will show- a)Declining phase
- b)Steady phase
- c)Exponential phase
- d)Lag phase
Correct answer is option 'C'. Can you explain this answer?
When the number of immigration and births is more than emigration and deaths, the growth curve of the population will show
a)
Declining phase
b)
Steady phase
c)
Exponential phase
d)
Lag phase
|
|
Navya Tiwari answered |
Exponential Growth Phase
When the number of immigration and births is more than emigration and deaths, the growth curve of the population will show an exponential phase. This means that the population will experience rapid and continuous growth over time.
Key Points:
- Immigration refers to the movement of individuals from one country to another for the purpose of permanently residing there.
- Births refer to the number of individuals being born within a population.
- Emigration refers to the movement of individuals out of a country to permanently reside in another.
- Deaths refer to the number of individuals dying within a population.
Explanation:
When the number of immigration and births exceeds the number of emigration and deaths, the population experiences a positive net migration rate and a positive natural increase rate. This leads to an increase in the total population size, which is reflected in an exponential growth phase on the population growth curve.
During the exponential phase, the population grows at an accelerating rate. This occurs because the number of individuals being added to the population through immigration and births is greater than the number of individuals being lost through emigration and deaths. As a result, the population size increases rapidly, leading to a steep upward curve on the growth graph.
The exponential growth phase is characterized by a doubling of the population size within a relatively short period of time. This is due to the compounding effect of population growth, where the larger the population becomes, the more individuals are available for reproduction and immigration, leading to even faster growth rates.
This phase can continue until certain limiting factors, such as resource availability or environmental constraints, begin to exert pressure on the population. At this point, the growth may start to slow down and eventually reach a steady phase or enter a declining phase if the limiting factors become severe enough.
In summary, when immigration and births outnumber emigration and deaths, the population undergoes exponential growth, leading to a rapid increase in population size over time.
When the number of immigration and births is more than emigration and deaths, the growth curve of the population will show an exponential phase. This means that the population will experience rapid and continuous growth over time.
Key Points:
- Immigration refers to the movement of individuals from one country to another for the purpose of permanently residing there.
- Births refer to the number of individuals being born within a population.
- Emigration refers to the movement of individuals out of a country to permanently reside in another.
- Deaths refer to the number of individuals dying within a population.
Explanation:
When the number of immigration and births exceeds the number of emigration and deaths, the population experiences a positive net migration rate and a positive natural increase rate. This leads to an increase in the total population size, which is reflected in an exponential growth phase on the population growth curve.
During the exponential phase, the population grows at an accelerating rate. This occurs because the number of individuals being added to the population through immigration and births is greater than the number of individuals being lost through emigration and deaths. As a result, the population size increases rapidly, leading to a steep upward curve on the growth graph.
The exponential growth phase is characterized by a doubling of the population size within a relatively short period of time. This is due to the compounding effect of population growth, where the larger the population becomes, the more individuals are available for reproduction and immigration, leading to even faster growth rates.
This phase can continue until certain limiting factors, such as resource availability or environmental constraints, begin to exert pressure on the population. At this point, the growth may start to slow down and eventually reach a steady phase or enter a declining phase if the limiting factors become severe enough.
In summary, when immigration and births outnumber emigration and deaths, the population undergoes exponential growth, leading to a rapid increase in population size over time.
Which of the following statements best describes the relationship between natality, mortality, immigration, and emigration in a population?
1. Natality and immigration both contribute to an increase in population size.
2. Mortality and emigration both contribute to an increase in population size.
3. Natality is the number of births per capita, while mortality refers to the number of deaths in a population during a given time period.
4. Immigration decreases the population density by bringing in individuals from outside the habitat.- a)Statements 1 and 3 are correct.
- b)Statements 2 and 4 are correct.
- c)Statements 1 and 4 are correct.
- d)Statements 3 and 4 are correct.
Correct answer is option 'A'. Can you explain this answer?
Which of the following statements best describes the relationship between natality, mortality, immigration, and emigration in a population?
1. Natality and immigration both contribute to an increase in population size.
2. Mortality and emigration both contribute to an increase in population size.
3. Natality is the number of births per capita, while mortality refers to the number of deaths in a population during a given time period.
4. Immigration decreases the population density by bringing in individuals from outside the habitat.
1. Natality and immigration both contribute to an increase in population size.
2. Mortality and emigration both contribute to an increase in population size.
3. Natality is the number of births per capita, while mortality refers to the number of deaths in a population during a given time period.
4. Immigration decreases the population density by bringing in individuals from outside the habitat.
a)
Statements 1 and 3 are correct.
b)
Statements 2 and 4 are correct.
c)
Statements 1 and 4 are correct.
d)
Statements 3 and 4 are correct.
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Anu Mukherjee answered |
Understanding Population Dynamics
Population dynamics is influenced by four key factors: natality, mortality, immigration, and emigration. Here’s a breakdown of the statements in the question:
Statement 1: Natality and Immigration Increase Population Size
- Natality, or birth rate, directly contributes to the growth of a population by adding new individuals.
- Immigration involves individuals moving into a population from outside areas, also increasing the total population size.
Statement 2: Mortality and Emigration Increase Population Size
- Mortality, or the rate of death, decreases population size as it removes individuals from the population.
- Emigration, the act of leaving a population, also reduces numbers. Therefore, this statement is incorrect.
Statement 3: Definitions of Natality and Mortality
- Natality is indeed defined as the number of births per capita in a given time period, which reflects population growth.
- Mortality refers to the number of deaths within that same time frame. Therefore, this statement is accurate.
Statement 4: Immigration and Population Density
- Immigration increases population density by introducing individuals to an area, rather than decreasing it. Hence, this statement is incorrect.
Conclusion
- Based on the analysis, statements 1 and 3 are correct, while statements 2 and 4 are incorrect. Thus, the correct answer is option 'A': Statements 1 and 3 are correct.
Population dynamics is influenced by four key factors: natality, mortality, immigration, and emigration. Here’s a breakdown of the statements in the question:
Statement 1: Natality and Immigration Increase Population Size
- Natality, or birth rate, directly contributes to the growth of a population by adding new individuals.
- Immigration involves individuals moving into a population from outside areas, also increasing the total population size.
Statement 2: Mortality and Emigration Increase Population Size
- Mortality, or the rate of death, decreases population size as it removes individuals from the population.
- Emigration, the act of leaving a population, also reduces numbers. Therefore, this statement is incorrect.
Statement 3: Definitions of Natality and Mortality
- Natality is indeed defined as the number of births per capita in a given time period, which reflects population growth.
- Mortality refers to the number of deaths within that same time frame. Therefore, this statement is accurate.
Statement 4: Immigration and Population Density
- Immigration increases population density by introducing individuals to an area, rather than decreasing it. Hence, this statement is incorrect.
Conclusion
- Based on the analysis, statements 1 and 3 are correct, while statements 2 and 4 are incorrect. Thus, the correct answer is option 'A': Statements 1 and 3 are correct.
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