Q2TYU - Campbell Biology

Question

Homeotic genes 

(A) encode transcription factors that control the expression of genes responsible for specific anatomical structures.

(B) are found only in Drosophila and other arthropods.

(C) are the only genes that contain the homeobox domain.

(D) encode proteins that form anatomical structures in the fly.

Step-by-Step Solution

Answer

1. The statement "encode transcription factors that control the expression of genes responsible for specific anatomical structures" is true.
2. The statement "are found only in Drosophila and other arthropods" is false.
3. The statement "are the only genes that contain the homeobox domain" is false.
4. The statement "encode proteins that form anatomical structures in the fly" is false.

Homeotic gene

Genes that regulate the development of certain body segments or structures are known as homeotic genes. Homeotic genes may be inactivated or overactivated as a result of a mutation, resulting in dramatic alterations in an individual's body shape and structure.

Explanation for option “(A)”

During the early development of an animal's embryo, a homeotic gene is one among a group of genes that regulate the pattern of body formation. These genes code for transcriptional factors or proteins that direct cells to generate distinct regions of the body.

 

Thus, homeotic genes encode transcription factors.

Therefore, the given statement is true.

Explanation for option “(B)”

The homeotic genes may be found in a wide range of organisms, including fruit flies, plants, and vertebrates. They are in charge of structural growth, which is an important element for all living organisms.

 

Thus, homeotic genes are not just found in Drosophila and arthropods.

Therefore, the given statement is false.

Explanation for option “(C)”

DNA homeoboxes are DNA sequences within genes that control anatomical development and morphogenesis patterns in mammals, fungi, and plants. There are 180 base pairs in a homeobox. When produced (in the form of a protein), it encodes a DNA binding domain.

 

Thus, homeobox is not just found in homeotic genes.

Therefore, the given statement is false.

Explanation for option “(D)”

The homeotic gene merely encodes the transcription factor that encodes the protein. It does not encode the protein essential for the anatomical development of an organism, such as a fly.

 

Thus, the homeotic gene does not encode the protein for anatomical development.

Therefore, the given statement is false.