When oxygen is lacking, animal cells change to . first blank: second blank: -lactic acid -lactic acid -pyruvic acid -pyruvic acid

What must be true for natural selection to heppen

What would be the result if crossing over did not happen during meiosis in humans? a. there would be less genetic variation in humans. b. parents would be more likely to look like their children. c. the human population could not reproduce. d. children would have more chromosomes.

Which of the following is an effect of the uneven heating of the earth by the sun? a sea breeze a land breeze a convection current all of the above