Answer:
A single gene on the Y chromosome plays a crucial role in the parental development of the testes.
Explanation:
Y chromosome is present only in males and this chromosomes is the distinguishing factor which separates males from females. It is the smallest chromosome but of utmost importance due to its sex determining feature. Up till now, studies show that Y chromosomes only carry limited amount of genes.
The Y chromosome, most importantly, comprises of the SRY gene. This is the gene responsible for determining the testis and for the development of the testis. The SRY gene is responsible for sex determination.
It is regulated by peristaltic movements. Then the pyloric sphincter will act as a valve at the junction between the stomach and duodenum, controlling the flow of chyme into the small intestine.
I would go with B) Nerves in the finger detect stimuli and send the message to the brain.
Wheres the picture for this
