Table 271Proposed Number of Hox Genes in Various Extant and Extinct

question 68

Multiple Choice

Table 27.1.Proposed Number of Hox Genes in Various Extant and Extinct Animals
-What conclusion is apparent from the data in Table 27.1?

• A)Land animals have more Hox genes than do those that live in water.
• B)All bilaterian phyla have had the same degree of expansion in their numbers of Hox genes.
• C)Acoel flatworms should be expected to contain seven Hox genes.
• D)The expansion in number of Hox genes throughout vertebrate evolution cannot be explained merely by three duplications of the ancestral vertebrate Hox cluster.
• E)Extant insects all have seven Hox genes.

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Definitions:

Neuropsychophysiology

The study of how the brain's physiology affects cognition, emotion, and behavior, often involving the understanding of neurological, psychiatric, and psychological disorders.

Psychological Processes

The mental functions and mechanisms that underlie human behavior, emotion, and thought.

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Cells of the immune system involved in defending the body against infectious diseases and foreign invaders.

Thymus Gland

An organ located in the chest that plays a vital role in the development of the immune system in early life.