Test: Population Interactions - NEET MCQ

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.

CominensaHsm is the relationship between two living individuals of different species in which one is benefitted while other is neither harmed nor benefined, e.g., Small fish (sucker fish) gets stuck near the bottom of a shark with the help of it's hold fast (modified dorsal fin) and is dispersed to distant areas. It also gets protection and derives its nutrition also and shark does not get any benefit or harm. Predation is an association between members of two species in which members of one species capture, kill and eat up members of other species, e.g.. Insectivorous plants like Drosera. Antibiosis : in this one organism inhibit growth of other organism through the secretion of antibiotics. This is based on biological antagonism and also known as allelopathy, e.g.. Smoother crops e.g.. Barley rye, millets are those which do not allow weeds to grow near by. Parasitism: in this type of association one member is benefitted. (parasite) and other is harmed (host), e.g.. Parasitic bacteria, viruses.

In ammensalism one component (population) is harmed and the other remains unaffected. The alga Microcystis release hydroxyl amine that kills the surrounding fauna but the alga itself remain unaffected. Parasitism is generally considered to deal with any small organism that live on or in another organism regardless of whether its effect is negative, positive or neutral. In predation one population adversaly affects the other by direct attack but nevertheless depends on other. In exploitation one species harms the other by making its direct or indirect use for support, shelter or food.

Praying mantis shows the phenomenon of camouflage by blending itself into the background. This enables it to elude predators.

A relationship between individuals of two species in which one species obtains food or other benefits from the other without either harming or benefiting the latter. The commensal—the species that benefits from the association—may obtain nutrients, shelter, support, or locomotion from the host species, which is unaffected. The commensal relation is often between a larger host and a smaller commensal. The host organism is essentially unchanged by the interaction, whereas the commensal species may show great morphological adaptation. This relationship can be contrasted with mutualism, in which both species benefit.

Explanation for correct option:

1. When a parasite lives in the body of the host then it is referred to as ectoparasitism.
2. Here the host-parasite relationship remains non-mutual.
3. Cuscuta is a stem parasite that wraps around the host plants and remains attached to them.
4. It is an example of ectoparasitism and in this type of parasitism the dependent organism or the parasite is dependent on the host for its food.

This type of mutualisn to called protocooperation. In this type, the sea anemone grows on the back of the hermit crab. It protects the crab with the help of its nematocysts. Ectoparasites live on the outside of host, e.g., human body louse. In this interaction, the parasite gets the benefit at the expense of the host. Commensalism is an assotiation between organisms in which one or both the species are benefitted and neither species is harmed. In amensalism one species is harmed, whereas the other is unaffected. Predation, parasitism and commensalism share a common characteristic, the interacting species live closely together.

It is an association between members of two species in which members of one species capture, kill and eat up members of other species. The former is called predator and later is called prey.

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).

Mutualism is a mutually beneficial relationship between individuals of two different species. None of the two is capable of living separately e.g., Nitrogen fixing Rhizobium bacteria living in root nodules of leguminous plants.
Protocooperation is non obligatory mutually beneficial relationship. 
In commensalism is an interaction in which one organism is benefited and the other is neither benefited nor harmed, e.g., Barnacles are often attached to the surface of whales for shelter and obtaining more food.
In amensalism without deriving much benefit, one organism inhibits the other by secreting allochemics. The phenomenon is called as antibiosis e.g., Trichoderma checks growth of Aspergillus.
Therefore, the correct answer is option D.