A farmer sprays insecticide on his crops to kill unwanted insects. Most of the insects die, and the chemicals have the effect of damaging the DNA of the insects that are not killed. Which of these has happened?

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion

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.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.