Normal homeostatic conditions require potassium concentrations to be about 1000 times higher inside the cell than in the blood. What mechanism does a cell use to move these small potassium molecules into the cell against the concentration gradient?
A.
active transport by proteins
B.
active transport by endocytosis
C.
passive transport by osmosis
D.
passive transport by diffusion

Are produced in the light reactions and used in the calvin cycle. a)nadh and atp b)electrons and sugar c)nadt+ and adp d)sugar molecules

Plz ! a scientist wants to produce a cow that makes a particular human protein in it’s milk the desired protein causes blood to clot and can be used to treat hemophilia (a blood clotting disorder). which of the following would be best for the scientist to use? a. genetic crosses. b. cloning. c. selective breeding. d. genetic engineering.

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.