What is the main difference between primary and secondary succession? A. The climax of primary succession is pine forest. B. Primary succession begins with bare rock. C. Secondary succession begins with mosses and lichens. D. Secondary succession includes frequent fires.

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.

The vaccine in a flu shot contains weakened flu viruses. how does a flu shot work with the immune system? a. it destroys lymphocytes. b. it destroys macrophages. c. it activates macrophages. d. it activates lymphocytes.

Aparent with freckles is crossed with a parent without freckles. the punnett square shows the possible genotypes and phenotypes of the offspring. which statement accurately describes the probability of phenotypes? a. the offspring are more likely to have freckles. b. the offspring are more likely to have no freckles. c. the likelihood of the offspring having freckles and not having freckles is the same. d. the likelihood of the offspring having freckles and not having freckles cannot be determined.