The plasma membrane of a cell is selectively permeable, which means it

When analyzing tree rings, what do scientists assume a thin ring indicates?

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.

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.