Acid rain is mostly a problem in the
a. northern hemisphere
b. eastern united states
c. southern hemisphere
d. southern part of europe

Which statement best describes the relationship between an allele and a gene? question 1 options: an allele is a variation of a gene that can be expressed as a phenotype. an allele is the part of a gene that attaches to messenger rna molecules. an allele is a segment of a dna molecule that controls replication of a gene.

Round seeds and yellow seed color are dominant to wrinkled seeds and green seed color. which punnett square represents the correct way to set up the cross rryy  ´  rryy? 

In a cladogram, what occurs at a node? a derived trait appears. evolution is stopped. an ancestor dies. the cladogram ends. aa as s as ss what are the chances that their offspring will have sickle cell anemia? 0% 25% 50% 100%