Question

Which of the following is most appropriately defined?
A. Parasite is an organism which always lives inside the body of other organisms and may kill it.
B. Host is an organism which provides food to other organisms.
C. Amensalism is a relationship in which one species is benefitted whereas the other is unaffected.
D. Predator is an organism that catches and kills other organisms for food.

Answer 1

Hint: If the parasite kills the organism on which it is living then the parasite will also die due to deficiency of nutrients. The organism on which the parasite lives is called its host and the supply of nutrients is done by the host only. Predator is the present on the third level of the food chains.

Complete answer:
For this question we will have to look at the options step by step:
First, we have the definition of parasite. We all know that the parasite depends upon the organism on which it is living for food and shelter. The organism which provides food and shelter top the parasite is called the host. As long as the parasite is living on the host, it cannot kill the host otherwise the parasite will not get food and shelter and it may also die.
Second, we have the definition of host. We have discussed the host and parasite relationship just above and according to the given option which is ‘they provide food to other organisms’ is wrong and the host provides food and shelter only to its parasite and no one else.
Next, we have the definition of amensalism, now in amensalism if we discuss, there is a relationship between two organisms in which the one organism is destroyed and the other organism remains unaffected by the presence of the other organism. According to the definition of options it is wrong.
Now the last option we have is a predator, and yes, the predators are the organism which catches and kills the other organisms in order to meet their requirement of food. Predators don’t have a specific prey; they can kill anyone in order to get food.

Therefore, the correct option is Option D.

Note:
Normally the relationship occurring between organisms of two different species is just because of the fact that one of the organisms is not able to produce its own food . It has to rely on the other organism to meet its nutritional requirement.