Which best describes how a vaccine works? A. The vaccine causes a nonspecific immune response.
O B. The vaccine cells kill bacteria.
C. The vaccine makes the body create memory cells.
O D. The vaccine produces white blood cells.

16. which of the following accurately describes a step within transcription? a. dna polymerase uses one strand of rna as a template to put together nucleotides. b. the dna strand is used as a template for which a complementary rna strand can be produced. c. the rna strand forms a template by which dna can be built. d. the rna strand is produced within the cytoplasm.

1. isogamy 1 organisms with gametes of the same size and shape 2. anisogamy organisms with gametes of different sizes and shapes 3. oogamy 2 organisms with gametes of the same shape but different sizes 4. gonads gamete-producing organs in lower plants 5. gametangia gamete-producing organs in animals

Explain how natural selection works