Question

which of the following are types of eukaryotic transcription factors? select all that apply.
a) repressors bind to specific sites on the dna and prevent the binding of activators.
b) genes are important for determining the body plan of an organism.
c) eukaryotic dna wraps around histones to form nucleosomes.
d) proteins form complexes that guide and stabilize the binding of rna polymerase to a promoter.
e) activators fold dna and cause the rate of transcription to increase.
f) a protein complex and single - stranded rna prevents protein production in the cytoplasm.

Explanation:

• Option A: Repressors are a type of eukaryotic transcription factor that can bind to DNA and inhibit activator binding, affecting transcription.
• Option B: This describes homeotic genes (Hox genes) which are involved in body plan determination, but these are genes, not transcription factors.
• Option C: This is about DNA packaging (nucleosome formation), not transcription factors.
• Option D: General transcription factors form complexes (like the pre - initiation complex) that help RNA polymerase bind to the promoter, so this is correct for transcription factors.
• Option E: Activators are transcription factors that can fold DNA (e.g., by bringing distant regions together) and increase transcription rate.
• Option F: This describes RNA interference (siRNA/miRNA - mediated gene silencing in the cytoplasm), not transcription factors (which act in the nucleus on DNA for transcription).

Answer:

A. Repressors bind to specific sites on the DNA and prevent the binding of activators.
D. Proteins form complexes that guide and stabilize the binding of RNA polymerase to a promoter.
E. Activators fold DNA and cause the rate of transcription to increase.