What is an allele?

a. one chromosome in a pair.
b. a form of a gene.
c. a homozygous genotype.
d. something that is always dominant.

How does the study of genetic disorders such as pku biologists understand normal alleles?

Which gas found in the earth's atmosphere greatly impacts the daily range of temperature on earth. a) oxygen b) hydrogen c) nitrogen d) water vapor

What's wrong with this ecological pyramid? (multiple choice)1. secondary consumers should be at the bottom of the pyramid2. the sun has an arrow leading to decomposers 3. primary consumers should come after the sun4. energy retained should increase from the bottom to the top5. the sun should be at the bottom of the pyramid