What type of molecule is encoded by homeobox genes?

• A. Transcription factors.
• B. Membrane receptors.
• C. Metabolic enzymes.
• D. Non-coding RNAs.

Answer: (A)

Homeobox genes encode transcription factors. They produce proteins that have a homeodomain, a ~60‑amino‑acid DNA-binding motif, which lets them attach to specific DNA sequences and regulate the transcription of downstream genes. In development, these transcription factors set up positional information and control patterns of gene expression that shape body plan and segment identity. The other options don’t fit because membrane receptors are signaling proteins at the cell surface, metabolic enzymes catalyze biochemical reactions, and non-coding RNAs do not encode proteins.