Enzymes are produced by groups of cells and tissues called blank

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.

what is the statement?

d. organisms have cells with different shapes and functions.