H-zone in a contracted sarcomere differ from that of a relaxed sarcomere . Yes its true because H-zone is narrower in contracted sarcomere. The functional unit of striated muscle is sarcomere. Sarcomere is the very basic unit of skelatal muscle. Between two Z line sarcomere is the repeated unit .Hence we can say that H-zone in a contracted sarcomere differ from that of a relaxed sarcomere.
ANSWER
Reduction of gene flow causes speciation because the populations with reduced gene flow both begin to evolve independently.
It is called peristalsis movement.
So, we have two heterozygotous parents, let's call then PL and pl.
if they had children, the children could have either polka-dot tails or not and either long eyelashes, or not, this gives us 4 groups ( so we can reject options A and D which only mention 2 types).
now, there is only one option to have a phenotype which corresponds to recessive allele: that both parents have the recessive allele. So the smallest group will be the one with solid tails and short eye-lashes,
the correct answer is
B. 9:3:3:1 ratio (9 polka-dot tails and long eyelashes, 3 polka-dot
tails and short eyelashes, 3 solid tails and short eyelashes, 1 solid
tail and short eyelash)
