List in the tabular form any three difference between the aves and the mammalia group

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

Acell in the human nervous system whose primary function is to form myelin and the blood-brain barrier, respond to injury, remove debris, and enhance learning and memory is called a(n) cell.

In the respiration-photosynthesis cycle shown above, what are the products of cellular respiration that belong in box 2?