Chapter 24, Problem 1TYK

Summary Introduction

To review:

The reason for the differences in evolution in plants and animals.

Introduction:

The plants and animals vary a great amount in their structure, function, and activity. On the basis of these differences, both these species evolved in a different manner. The basic difference between them is that plants are immobile or stationary, while the animals are highly mobile.

Explanation of Solution

The plants are sessile organisms that do not move or change their location. The leaves, roots, and certain other parts like pollens and seeds are mobile. The leaves are positioned in an orientation so as to obtain maximum amount of sunlight. The plants being immobile also developed photosynthetic pathway to manufacture their own food. The roots move in search of water and nutrients in the soil. On the other hand, animals are mobile and they change their location in search of food, for mating or to avoid predation.

The plants’ cells are enclosed within a cell wall, which is absent in case of animals. The cell wall provides rigidity to the plant because they are immobile. The development in plant continues throughout their lifetime, while the animals grow up to a certain stage only. This happens because the plants, unlike the animals are exposed to nearly all the environmental factors that lead to their wear and tear continuously.

The mode of reproduction is also quite different in both the species. Animals mate with the help of gametes (sperm from the male and ovum from the female). On the other hand, plants employ pollen grains (male gametes) and ovules (female gametes) for fertilization. The male and female organisms require to be in close vicinity in animals for reproduction to take place. While, the pollens in the plants can transfer to the ovary through air, water, and insects.

Conclusion

Therefore, it can be concluded that the structure, habitat, and mode of reproduction made the plants and animals different as far as evolution is concerned.