The "cambrian explosion" refers to a. the creation of earth. b. the development of the first true cell. c. the origination of life. d. the origination of all major phyla of animals. e. the mass extinction of dinosaurs.

In general, how long does it take to accomplish a long-term goal? a.a few days to a weekb.a few weeks to a monthc.a few months to a yeard. more than a year

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.

For a comparative or experimental investigation, scientists often make a testable about a scientific question, and then they test it in the investigation. a.control b.hypothesis c.procedure d.system