Crossing over plays a critical role in increasing the genetic variation among offspring of sexual reproduction. a. True
b. False

Fan egg cell containing the (n+1) number of chromosomes combines with a sperm cell containing the (n) number of chromosomes, what is the result of this union? a) all future somatic cells of the organism will contain the (2n + 1) number of chromosomes. b) all future somatic cells of the organism will contain the (2n - 1) number of chromosomes. c) only certain somatic cells of the organism will contain the (2n + 1) number of chromosomes. d) all future somatic cells of the organism will contain the normal diploid number of chromosomes.

All eukaryotic cells contain small bodies called

Which line in the graph above best illustrates an effect of the carbon dioxide level in the blood on breathing rate before, during and after a period of exercise? 1.b,2.c,3.a,4.d