In rats, the allele for long whiskers is dominant to the allele for short whiskers. At another gene locus, a dominant allele produces whiskers and the recessive allele produces a rat with no whiskers. The alleles at these 2 gene loci assort independently. Two rats that are heterozygous at both gene loci are crossed. What percentage of the offspring do you expect will have whiskers? ( Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5 )

25

Explanation:

if you make a punnet square you will see that the allele for having whiskers is 25%

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.

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.