Which of the following does NOT provide molecular cues that control pattern formation in Drosophila?

• A. Homeotic genes
• B. Maternal effect genes
• C. Segmentation genes
• D. Hemoglobin genes

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the concept of pattern formation in Drosophila. Pattern formation refers to the process by which cells in a developing embryo acquire different identities according to their spatial positions, leading to the organized body plan of the organism.
2. Step 2: Identify the roles of the gene categories listed: Maternal effect genes provide initial positional information by depositing mRNA or proteins in the egg; Segmentation genes interpret these cues to divide the embryo into segments; Homeotic genes specify the identity of each segment, determining what structures will form there.
3. Step 3: Recognize that hemoglobin genes are involved in encoding proteins for oxygen transport in blood and do not play a role in embryonic pattern formation or developmental spatial cues.
4. Step 4: Conclude that among the options, hemoglobin genes do NOT provide molecular cues for pattern formation in Drosophila, unlike the other gene types which are directly involved in establishing the body plan.
5. Step 5: Summarize that the correct answer is hemoglobin genes because they are unrelated to developmental patterning processes in Drosophila.