What does an organism's genotype describe? the allele combination for a trait
the physical appearance of a trait
the number of alleles on a gene
the number of different traits inherited

the allele combination for a trait

Explanation:

The genotype describes which alleles (versions) of a gene an organism has. Diploid organisms, such as humans, have two copies of each gene. Sometimes these alleles are the same and the individual is h0m0zygous for that gene. If they are different, the individual is heterozygous for that gene.

The physical appearance of a trait is the phenotype.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

looks like the answer is     c     to me!