Question

Which of the following is correct among the following statements related to species interaction?

• A. Calotropis releases a strong smell to prevent cattle and goats from eating its leaves.
• B. Predators help in maintaining species diversity in a community.
• C. Totally unrelated species never compete for the same resource.
• D. Closely related species competing for the same resources cannot co-exist indefinitely even if the resources are unlimited.
• A. Pisaster (starfish) and some invertebrates
• B. Abingdon tortoise and goats
• C. Sea anemone and clown fish
• D. Flamingo and resident fishes
• A. Mosquito
• B. Cuckoo
• C. Cuscuta
• D. Ticks
• A. Parasitism
• B. Competition
• C. Predation
• D. Commensalism
• A. Sigmoid shaped growth curve
• B. J-shaped growth curve
• C. Verhulst-Pearl logistic growth
• D. Logistic Growth

Answer 1

The Correct Option is B

Let's evaluate each statement regarding species interactions:

(1) Calotropis releases a strong smell to prevent cattle and goats from eating its leaves: This is incorrect. While Calotropis is known to be toxic to some herbivores, its strong smell is not the main mechanism it uses to prevent cattle and goats from eating its leaves. It produces toxic compounds that deter herbivores, but the statement about smell being the primary deterrent is not accurate.

(2) Predators help in maintaining species diversity in a community: This is correct. Predators play a crucial role in maintaining species diversity in ecosystems by regulating prey populations. By controlling the numbers of dominant species, predators allow less dominant species to thrive, thus increasing overall diversity in the community.

(3) Totally unrelated species never compete for the same resource: This is incorrect. Unrelated species can still compete for similar resources, such as food, space, or light. This competition, even between unrelated species, is a common ecological interaction.

(4) Closely related species competing for the same resources cannot co-exist indefinitely even if the resources are unlimited: This is incorrect. According to the competitive exclusion principle, closely related species that compete for the same resources may not be able to coexist in the same ecological niche indefinitely. However, in some cases, species can adapt or evolve different strategies to share resources or occupy slightly different niches, allowing them to coexist.

Thus, the correct answer is (2) Predators help in maintaining species diversity in a community.

Answer 2

Predators play a crucial role in maintaining species diversity by controlling prey populations, preventing any single species from becoming overly dominant, thus supporting ecosystem balance.

Answer 3

Commensalism is a type of symbiotic relationship where one organism benefits from the interaction, while the other organism is neither helped nor harmed.

Let's evaluate each option:

(1) Pisaster (starfish) and some invertebrates: This is not an example of commensalism. It is more of a predation or competition relationship, as some invertebrates may be prey for the starfish, or they may compete for resources.

(2) Abingdon tortoise and goats: This is not a classic example of commensalism. It is an example of a relationship where goats may compete for resources with the tortoise, rather than one benefiting without harming the other.

(3) Sea anemone and clown fish: This is an example of commensalism. The clownfish benefits from the protection and shelter provided by the sea anemone, while the anemone is not affected by the clownfish's presence. The clownfish receives protection from predators and food scraps, but the sea anemone is neither helped nor harmed.

(4) Flamingo and resident fishes: This is more likely to be a mutualistic relationship, where flamingos may benefit from the resident fish in terms of food availability (the fish may stir up food for the flamingos), but it's not a classic example of commensalism.

Thus, the correct answer is (3) Sea anemone and clown fish, as this is a classic example of commensalism.

Answer 4

The relationship between the sea anemone and clownfish exemplifies commensalism, where the clownfish gains protection among the anemone’s stinging tentacles, while the anemone is unaffected, benefitting one without affecting the other.

Answer 5

Let's evaluate each organism to see whether it is classified as a parasite:

(1) Mosquito: A mosquito is a parasite in the sense that it feeds on the blood of other organisms, typically causing harm to the host. Mosquitoes are considered ectoparasites.

(2) Cuckoo: The cuckoo is not classified as a true parasite. Cuckoos are brood parasites, meaning they lay their eggs in the nests of other birds, leaving the host birds to raise their young. While this behavior is parasitic, it's different from the typical parasitic relationship because the cuckoo doesn't directly feed off the host, but exploits the host’s parental care.

(3) Cuscuta: Cuscuta is a parasitic plant. It attaches itself to other plants and absorbs nutrients from them, making it a true parasite.

(4) Ticks: Ticks are ectoparasites that feed on the blood of mammals, birds, and sometimes reptiles, causing harm to their hosts.

Thus, the correct answer is (2) Cuckoo, as it is a brood parasite but not classified as a typical parasite like the others.

Answer 6

The cuckoo is a brood parasite, relying on other bird species to raise its young by laying eggs in their nests. It differs from true parasites, which directly feed on their hosts, like mosquitoes, Cuscuta, and ticks.

Answer 7

The process described in the question refers to a situation where the fitness (specifically the intrinsic rate of increase (r)) of one species is significantly reduced due to the presence of another species. This is a classic case of competition.

(1) Parasitism: In parasitism, one species benefits at the expense of the other, but it doesn't directly refer to a reduction in fitness due to the presence of another species in the same way that competition does.

(2) Competition: Competition occurs when two species vie for the same limited resources (such as food, space, or mates). This results in a reduction in the fitness of one or both species because the available resources are shared, which lowers the reproductive rate or survival rate of the competing species. This is the correct answer.

(3) Predation: In predation, one species kills and eats another species, but this doesn’t directly reduce the fitness of the predator in the presence of its prey (it actually increases the predator's fitness).

(4) Commensalism: In commensalism, one species benefits, and the other is unaffected. There is no reduction in fitness for either species in this relationship.

Thus, the correct answer is (2) Competition, as it involves a scenario where the fitness of one species is reduced in the presence of another species.

Answer 8

In competition, the presence of another species lowers the fitness (r-value) of one or both species as they vie for similar resources. This interaction can reduce their growth rate due to resource limitation.

Answer 9

Let's evaluate each option in relation to the realistic growth model:

(1) Sigmoid-shaped growth curve: This is associated with the logistic growth model. The sigmoid curve (S-shaped curve) shows the growth of a population that increases rapidly at first but then slows down as it approaches the carrying capacity of the environment. This is a characteristic of the realistic growth model, which considers limiting factors like resource availability.

(2) J-shaped growth curve: This is not associated with the realistic growth model. The J-shaped growth curve represents exponential growth, where the population grows rapidly without any constraints, continuing to increase exponentially. This type of growth is unrealistic in nature as it ignores environmental limits.

(3) Verhulst-Pearl logistic growth: This is a form of logistic growth and is associated with the realistic growth model. The Verhulst-Pearl model describes population growth with limitations, incorporating factors like carrying capacity and resource limitations.

(4) Logistic Growth: This is directly associated with the realistic growth model, as it describes a population growth that initially grows exponentially but slows down as it approaches the environment's carrying capacity.

Thus, the correct answer is (2) J-shaped growth curve, as it is associated with exponential growth and not the realistic growth model, which incorporates environmental constraints.

Answer 10

The J-shaped growth curve represents exponential growth without accounting for environmental resistance or carrying capacity, making it unrealistic for natural populations. Realistic growth models, like the logistic growth curve, consider environmental constraints.