If a man is heterozygous (aa) for a trait, predict his possible sperm.
a. his sperm would not carry either of the alleles.
b. 100% of his sperm would carry both of the alleles (aa)
c. 50% would carry a dominant
a. and 50% would carry a recessive
a. d. 50% would carry two dominant alleles (aa) and 50% would carry two recessive alleles (aa)

The answer is c. 50% would carry a dominant A and 50% would carry a recessive a.

Sperm is a male gamete and as it is known gametes are haploid cells. Haploid cells have only one allele in the loci. So a man heterozygous (Aa) for some trait will have in his sperm either allele A or allele a. The chance to have either one of them is 50% since there are only two options.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.

i thinking chemical change