Answer: C
Explanation: Left ventricle. With the thickest muscle mass of all the chambers, the left ventricle is the hardest pumping part of the heart, as it pumps blood that flows to the heart and rest of the body other than the lungs.
Answer:
Alleles for feather colour exhibit incomplete dominance or co-dominance.
50% gray offspring + 50% black offspring
Explanation:
<em>It means that the alleles for feather colour in the hen exhibit incomplete dominance or co-dominance over one another.</em>
Assuming the allele for white colour is B, white colour will be b while the heterozygote Bb gives the gray phenotype.
Gray rooster + gray hen = 15 gray chicks, 6 black chicks and 8 white chicks.
15:6:8 is roughly 2:1:1 which is phenotypic ratio obtainable from crossing two heterozygous individuals as pointed out by Mendel.
Bb x Bb = 1BB, 2Bb, and 1bb
Crossing the gray rooster (Bb) with a black hen (bb):
Bb x bb = Bb, Bb, bb, and bb
= 2Bb (gray):2bb (black)
50% of the offspring will be gray while the remaining 50% will be black.