. A is a physical trait one can see, while a is the section of DNA associated with a certain trait that causes it to appear.
allele, gene trait
genotype, phenotype
DNA, inherited trait
phenotype, genotype

Phenotype

Genotype

Explanation:

Phenotype is the physical appearance because it's the outward expression of the person, which is determined by one's Genotype.

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.

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.