Which best describes the sex chromosomes in humans?
O
A. Males have two X chromosomes.
O
B. Females have one X and one Y chromosome.
O
C. Males have two Y chromosomes.
O
D. Males have two different chromosomes.

What type of organism is a one-celled organism that functions as a single unit? a. bi-celled b. single-celled c. pre-celled d. multi-celled

If the nucleus of a cell was removed the cell wouldn’t be able to make proteins because

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population.b) the separated population is small, and genetic drift occurs.c) the isolated population is exposed to different selection pressures than the ancestral population.d) different mutations begin to distinguish the gene pools of the separated populations.e) gene flow between the two populations is extensive.