The equation of Verhulst-Pearl logistic growth is From this equation, K indicates [2024]
intrinsic rate of natural increase
biotic potential
carrying capacity
population density
Given below are two statements: [2024]
Statement I: Gause's competitive exclusion principle states that two closely related species competing for different resources cannot exist indefinitely.
Statement II: According to Gause's principle, during competition, the inferior will be eliminated. This may be true if resources are limiting.
In the light of the above statements, choose the correct answer from the options given below.
Both Statement I and Statement II are true.
Both Statement I and Statement II are false.
Statement I is true but Statement II is false.
Statement I is false but Statement II is true.
(4)
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 eventually. This may be true if resources are limiting, but not otherwise.
Plants offer rewards to animals in the form of pollen and nectar and the animals facilitate the pollination process. This is an example of: [2023]
amensalism
competition
commensalism
mutualism
(4)
The relationship between plants and animals is the most spectacular and evolutionarily fascinating example of mutualism. Plants need the help of animals for pollinating their flowers and dispersing their seeds. Animals get rewards in the form of pollen and nectar for pollinators and juicy and nutritious fruits for seed dispersers.
If there are 250 snails in a pond, and within a year their number increases to 2500 by reproduction. What should be their birth rate per snail per year? [2023]
10
9
25
15
(2)
Total number of snails in a pond (in the beginning) = 250
Total number of snails after a year = 2500
Number of snails added = 2500 - 250 = 2250
Birth rate = New snails added / Total number of snails in the beginning = 2250 / 250 = 9 individuals per snail per year
For chemical defence against herbivores, Calotropis has [2023]
cardiac glycosides
strychnine
toxic ricin
distasteful quinine
(1)
Calotropis plant produces highly poisonous cardiac glycosides as a defence against herbivores. Thus, herbivores do not browse on this plant.
Match List I with List II [2023]
| List I (Interaction) | List II (Species A and B) |
|---|---|
| A. Mutualism | I. + (A), 0 (B) |
| B. Commensalism | II. – (A), 0 (B) |
| C. Amensalism | III. + (A), – (B) |
| D. Parasitism | IV. + (A), + (B) |
Choose the correct answer from the options given below:
A-IV, B-III, C-I, D-II
A-III, B-I, C-IV, D-II
A-IV, B-II, C-I, D-III
A-IV, B-I, C-II, D-III
(4)
| Population Interaction | Species A and B |
|---|---|
| Mutualism | + (A), +(B) |
| Commensalism | + (A), 0(B) |
| Amensalism | - (A), 0(B) |
| Parasitism | + (A), -(B) |
Given below are two statements: [2023]
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 is correct but Statement II is false.
Statement I is incorrect but Statement II is true.
Both Statement I and Statement II are true.
Both Statement I and Statement II are false.
(1)
In general, herbivores and plants appear to be more adversely affected by competition than carnivores.
Match List I with List II. [2023]
| List I | List II |
| A. Logistic growth | I. Unlimited resource availability condition |
| B. Exponential growth | II. Limited resource availability condition |
| C. Expanding age pyramid | III. The percent individuals growth of pre-reproductive age is largest followed by reproductive and post-reproductive age groups |
| D. Stable age pyramid | IV. The percent individuals of pre-reproductive and reproductive age group are same |
Choose the correct answer from the options given below:
A-II, B-IV, C-I, D-III
A-II, B-IV, C-III, D-I
A-II, B-I, C-III, D-IV
A-II, B-III, C-I, D-IV
(3)
Logistic growth → Limited resource availability condition
Exponential growth → Unlimited resource availability condition
Expanding age pyramid → The percent individuals of pre-reproductive age is largest followed by reproductive and post-reproductive age groups
Stable age pyramid → The Percent individuals of pre-reproductive and reproductive age groups are same
Match List I with List II. [2023]
| List I (Interacting species) | List II (Name of Interaction) |
|---|---|
| A. A Leopard and a lion in a forest/grassland | I. Competition |
| B. A cuckoo laying egg in a Crow's nest | II. Brood parasitism |
| C. Fungi and root of a higher plant in mycorrhizae | III. Mutualism |
| D. A cattle egret and a cattle in a field | IV. Commensalism |
Choose the correct answer from the options given below:
A-III, B-IV, C-I, D-II
A-II, B-III, C-I, D-IV
A-I, B-II, C-III, D-IV
A-I, B-II, C-IV, D-III
(3)
A leopard and a lion in a forest/grassland → Competition
A cuckoo laying egg in a crow’s nest → Brood parasitism
Fungi and root of higher plant in mycorrhizae → Mutualism
A cattle egret and a cattle in a field → Commensalism
Which one of the following statements cannot be connected to predation? [2022]
It helps in maintaining species diversity in a community.
It might lead to extinction of a species.
Both the interacting species are negatively impacted.
It is necessitated by nature to maintain the ecological balance.
(3)
In predation one species derives benefit while the other one is harmed. So, in this type of population interaction one species is positively impacted, whereas another one is negatively impacted.
