Q32.1-1CC. Summarize the main stages of ani... [FREE SOLUTION]

Chapter 32: Q32.1-1CC. (page 673)

Summarize the main stages of animal development. What family of control genes plays a major role?

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In the majority of animals, cleavage of the zygote generates a structure termed blastula. It is followed by the gastrulation process, which marks the embryo鈥檚 inward folding and formation of layered embryonic tissues. The differentiation of embryonic layers accounts for the production of different animals.

The division and development of the zygote are regulated by control genes, and in the majority of animal groups, Hox gene sets the function to control and regulate animal development.

Step by step solution

Kingdom Animalia

The domain Eukaryote has four biological kingdoms, and the Kingdom Animalia is one of them. It is characterized by the presence of a multicellular body, the absence of a cell wall, and heterotrophic nutrition.

The organisms of the animal kingdom are classified into various groups based on the differences in body structure and physiological activities. The main two groups are vertebrates and invertebrates.

Sexual Reproduction

The organisms of the world have two mechanisms for reproduction; sexual reproduction is the method in which the involvement of two parental organisms accounts for the diversity of the genome in the population. This mode of reproduction is absent in prokaryotic organisms.

Animal development

The first cell that develops after fertilization is denoted as a zygote. In major animal groups, the zygote divides through cleavage division and produces a cellular mass termed blastula. The next step is that of gastrulation, which involves the folding of one of the embryo鈥檚 ends to produce embryonic tissue layers.

Further development occurs by the differentiation of the embryonic layers, which produces the animals belonging to diverse groups of the animal kingdom.

The development of animals is regulated by several gene sequences, which account for the differentiation in animals. Despite these differences, a set of regulatory hox genes are present in the genome of the majority of animals, and it regulates developmental processes.