You have one tree that produces big yellow apples and another tree that produces small red apples. when the two are crossed, you find that half the offspring trees produce big red apples and half produce big yellow apples. what are the genotypes of the parents? a = big apples; a = small apples; r = red apples; r = yellow apples. aarr and aarr aarr and aarr aarr and aarr aarr and aarr

The genotypes of the parents are AArr and aaRr

Since, half the offspring trees produce big red apples and half produce big yellow apples we can conclude:

That all of the offspring inherited dominant trait for the size of apple (all of them are big) so, AA from one parent and aa from another can combine and form all heterozygous genotypes Aa. On the other hand, trait for the apple color is expressed 50-50-% (rr and Rr form Rr Rr rr rr genotypes).

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.