Question

Identify the incorrect statement

I. Thermoregulation is energetically the least expensive process for many organisms like shrews and hummingbirds.

II. 99% of animals and nearly all plants cannot maintain their constant internal environment.

III. During the course of evolution, the cost and heights of maintaining a constant internal environment are discarded.

IV. In aquatic animals, the osmotic concentration of the body fluids changes with that of the ambient water osmotic concentration.

A. I and II
B. III and IV
C. I and III
D. II and III

Answer 1

Hint: The biological mechanism responsible for ensuring a constant internal body temperature is known as thermoregulation. A lot of energy is spent by organisms (mostly small animals) in this process. It can be regarded as an expensive process. Also, the benefits of the internal environment like heights and the cost are taken into consideration during the course of evolution.

Complete step-by-step answer:
Many organisms expend a lot of energy on thermoregulation. This is especially true for small animals such as shrews and hummingbirds. Heat loss or gain is proportional to the surface area. Because small animals have a larger area of the surface relative to their volume, they lose body heat quickly when it is cold. So, it is an expensive process. Thus we can say that statement I is incorrect.
Conformers are animals and plants whose body temperature and osmotic concentration vary according to their surroundings. Almost all plants and nearly all animals are unable to maintain a constant internal environment. Such animals and plants are nothing more than conformists. So, statement II is correct.
The cost and benefit of maintaining the internal environment are considered during the evolution process. Only those species that evolved to keep their internal environment constant during evolution are capable of performing all physiologic and biochemical functions with optimal efficiency, increasing their fitness to survive in nature. They would not have survived/been in existence today if they had not evolved millions of years ago. They exist today because of the benefits mentioned above for maintaining a consistent internal environment. As a result, the benefits of the internal environment are taken into account during the evolution process. Thus statement III is incorrect.
The osmotic concentration of body fluids in aquatic animals varies with the osmotic concentration of ambient water. These animals and plants are nothing more than conformists. Some species have acquired the ability to regulate themselves, but only within a narrow range of environmental conditions, after which they plainly conform. Thus, statement IV is correct.

Hence, option C is the correct option.

Note: The keyword to know that statement I is correct or not is least. Many consider
Statement I to be the correct one because thermoregulation is an expensive process but they make the mistake of missing the word least.