x or y because both can cause it
Natrual variations i think
Dominant refers to the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked.
Answer:
As a result of photosynthesis oxygen and sugar
The answer is 700 milligrams needed toddlers should consume
per day. Children need enough calcium to support their growing bones and teeth.
Calcium is one of the body's most essential minerals and also has other necessary
roles to play, including supporting a healthy nervous system and muscle
function.