-Dll Is a Gene Known to Direct Limb Development in the Fruit

question 24

Multiple Choice

-Dll is a gene known to direct limb development in the fruit fly. Researchers studying this gene have found that it is also expressed in developing appendages in animals from many other phyla, supporting the hypothesis that all animal appendages may be homologous. However, suppose researchers looking at Dll activity had instead found the results shown in the preceding table. These results suggest instead that ________.

• A) Dll is not actually involved in appendage development
• B) appendages evolved separately in protostomes and deuterostomes
• C) appendages coevolved with segmentation
• D) all animal appendages are homologous

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Definitions:

Behaviour Therapy

A type of psychotherapy that focuses on changing unwanted behaviors through various techniques, such as conditioning.

Insight Therapy

A psychological treatment aimed at increasing a person’s awareness of underlying motives and defenses.

Relaxation Methods

Techniques designed to reduce tension and stress, promoting a state of calmness and tranquility.

Aversion Therapy

A behavioral treatment method that uses unpleasant stimuli to reduce or eliminate undesirable behaviors.