The exchange of segments of DNA(crossing Over) between the members of a pair of chromosomes
A. ensures that variation within a species never occurs.
B. acts as a source of variations within a species,
C. always produces genetic disorders,

What sentence best supports the statement that hormones are involved in the regulation of homeostasis? a. the hormone erythropoeitin increases the production of red blood cells when oxygen levels are low. b. the hormone oxytocin promotes labor contractions of the uterus during childbirth. c. the hormone melatonin induces sleep and its production is slowed by exposure to light. d. the hormone cortisol suppresses the immune system and is produced when the body is under stress.

Which is the graph of the piecewise function f(x)? f(x) = image for option 1 image for option 2 image for option 3 image for option 4

Explain why scientists use the word dominant for certain traits.