a molecular biologist measures the mass of cofactor a in an average yeast cell. the mass is . what is the total mass in micrograms of cofactor a in a yeast colony containing cells? write your answer as a decimal.

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this

Which of the following is caused by reproductive isolation within a species? a. a decrease in gene flow b. an increase in genetic flow c. a decrease in genetic drift d. an increase in gene flow

How do the sperm cells get from the stigma to the ovules? a. they slide down the petals to the bottom of the flower. b. they travel through pollen tubes. c. they travel along filaments. d. insects carry the sperm cells from the stigma to the ovules.