Which of the following is the adaptation that allows animals to survive in high altitudes, which contain lower levels of oxygen?
a. migration
b. higher levels of hemoglobin
c. insulating feathers
d. higher body temperatures

Which phase of the cell cycle ensures that identical copies of the dna are made for daughter cells?

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes

Which of the following organisms are capable of self-fertilization? a.plants b.tigers c.humans