Homeotic Genes Contain a Homeobox Sequence That Is Highly Conserved

question 23

Multiple Choice

Homeotic genes contain a homeobox sequence that is highly conserved among very diverse species.The homeobox encodes a protein domain that binds to DNA to regulate development of the embryo.The selective expression of homeotic genes,over time and space,is central to pattern formation during development.Based on this information,which of the following statements would you expect to be correct?

• A)Homeotic genes are selectively expressed over space and time during development.
• B)A homeobox-containing gene has to be a developmental regulator.
• C)Homeoboxes cannot be expressed in nonhomeotic genes.
• D)All organisms must have homeotic genes.

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Definitions:

Transamination

A chemical process in which an amino group is transferred from one amino acid to a keto acid, altering amino acid structure.

Protein Synthesis

The biological process by which cells generate new proteins, involving transcription of DNA to mRNA and then translation of mRNA on ribosomes to assemble the protein.

Ketogenesis

Production of ketone bodies, such as from acetyl-CoA.

Gluconeogenesis

A metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates such as lactate, glycerol, and amino acids.