Cactus Is a Maternal-Effect Gene Coding for an Inhibitory Protein

question 11

Multiple Choice

Cactus is a maternal-effect gene coding for an inhibitory protein in the Drosophila Toll signaling pathway that binds to Dorsal in the cytosol and keeps it from nuclear entry. Would you expect maternal loss-of-function mutations in Cactus to give rise to dorsalized or ventralized embryos? What about loss-of-function mutations in Decapentaplegic (Dpp) ?

• A) Dorsalized; dorsalized
• B) Dorsalized; ventralized
• C) Ventralized; dorsalized
• D) Ventralized; ventralized

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Definitions:

DNA Replication

The process by which a cell duplicates its DNA, making two identical copies, before cell division.

Sister Chromatids

Identically replicated forms of a chromosome connected by a centromere, formed during cell division.

Enzymes Production

The process by which living organisms synthesize enzymes, proteins that catalyze biochemical reactions.

Nucleolus

The nucleolus is a small, dense region within most nuclei of eukaryotic cells, primarily involved in the assembly of ribosomes through the processing and modification of RNA.