Chapter 24, Problem 2A

Summary Introduction

To analyze:

The animal that produces both sperm and egg.

Introduction :

Different animals have different features in their feeding process, development of their body, and the features that involve as their support in the body structure. Some of the animals are invertebrates and it includes all the animals that have exoskeletons. The exoskeletons is the outer coverage of the body, it is the tough or hard outer cover, it provides support to the soft tissue of the body, avoid loss of water, and also give protection against predators. The endoskeleton is the internal covering of some of the vertebrates. It includes sea stars and sea urchins; they are made of calcium carbonate, cartilage, etc.

Explanation of Solution

Unlike different cell structure different animals have different reproductive structure. One of the features includes hermaphrodites, the animals that produce both sperms and egg. They produce egg and sperm simultaneously with the help of sexual reproduction. In many animals the zygote undergoes mitotic cell division and form two cells that are termed as embryo. The division of embryonic cell continue to form blastula. Animals like frogs undergoes further division of cell to form gastrula. Gastrula is a two layer sac with an opening at one end formed in embryonic development. It seems like a double bubble that means one bubble inside another bubble.

Conclusion

The gastrula is a two layer sac with an opening at one end formed in embryonic development.