Question

Which of the following systems are well developed in parasitic animals?
A. Digestive system
B. Respiratory system
C. Reproductive system
D. All of the above

Answer 1

Hint: The organisms that exhibit a symbiotic relationship with the hosts, but have a detrimental effect on the host. It causes harm to the host. The organism is structurally adapted to the type of nutrition.

Complete answer:
The organisms exhibiting parasitism remain in close contact with the host organisms. These organisms are dependent on the hosts for the whole of their lifetime. These organisms have a very well developed reproductive system since it should have the ability to reproduce vigorously inside the host organisms. The more the number of offsprings that are produced, the greater the efficacy of the infection. The other systems in the organisms are either primitive or absent. They are devoid of locomotive orgasms as well as respiratory and digestive systems.
-The organisms practicing parasitism possess a primitive digestive system, or it might be completely absent. Since these organisms depend on the host for nutrition, they do not require a well-developed digestive system.
-Respiratory system is also primitive in parasites.
Thus, from the above-given options, the most appropriate one is option C, i.e., Reproductive system, to increase the efficacy of infection.

Note: The host organisms have evolved to develop various defense strategies against the parasites. The various mechanisms are physical barriers such as vertebrate skin, immune systems, and chemical methods such as defensive chemicals in some plants.