Answer Happy

In a weird species of worm(?), the presence of hair on the head is controlled by a keratinase enzyme. This enzyme is controlled by two genes, H and N. For each genotype possibility for these two genes, the enzyme pathway and resulting phenotype is shown below. HAN_ ΗΗΝ or HhN hh H_nn Protein H Protein H Protein H Protein N Protein N Proin N Keratinase Keratinase Keratinase

Answer the following questions about this genetic system. [Select] epistasis? [Select] influence this phenotype? [Select] The interaction between the N and H genes represents what type of Based on the pathway shown, what do the H and N genes likely each do to Why does the worm still not have any hair even when Protein N is not expressed (as shown in the second row of the picture)?

✓ [Select] Dominant epistasis Dominant (or Polymeric) gene interaction Recessive epistasis Duplicate (dominant epistasis) Complimentary (or Double Recessive) gene interaction Dominant suppression [Select] in the N and H genes represents what type of shown, what do the H and N genes likely each do to Why does the worm still not have any hair even when Protein N is not expressed (as shown in the second row of the picture)?

epistasis? ✓ [Select ] The H gene and N gene both code for the keratinase, because without either gene, no keratinase is made The N gene codes for a protein required for the production of keratinase, and the H gene interferes with its expression The H gene and N gene both code for proteins that can make keratinase, but neither are required since each can make the required The H gene codes for a protein required to make keratinase. The N gene codes for a protein that destroys or inhibits the protein made expressed (as shown in the second row of the picture)?

influence this phenotype? ✓ [Select] Gene H likely shows incomplete penetrance, so it is not expressed 100% of the time The H gene and the protein it codes for is not required to make keratinase Even though the N gene is not producing the inhibitory protein N, the H gene is also not making any of the required protein H need to This is an example of dominant gene interaction, where both dominant alleles are required to produce a phenotype