Spicules are ____ that are found in sponges

a. fibrous skeletal proteins
b. specialized digestive cells
c. complicated pore openings and passageways
d. needlelike skeletal structures made up of silica or calcium carbonate
e. feeding cells with a flagellum surrounded by a collar


D

Biology & Microbiology

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Sodium-potassium pumps increase the charge gradient across the neuron membrane by moving ________

a. one potassium ion into the cell and one sodium ion out b. two potassium ions into the cell and three sodium ions out c. three potassium ions into the cell and two sodium ions out d. two potassium ions and three sodium ions out of the cell

Biology & Microbiology

Skin grafts between identical twins are more successful than grafts between more unrelated individuals. Why?

A. Identical twins share the same uterine environment. B. Twins are exactly matched in age. C. Identical twins have identical HLA alleles. D. Identical twins are the same sex. E. None of these is true.

Biology & Microbiology

Three fatty acids bonded together with a glycerol are found in a(n):

A. triglyceride. B. phospholipid. C. alcohol. D. enzyme. E. chlorophyll pigment.

Biology & Microbiology

Using PGD to screen for embryos that would become suitable donors for siblings is illegal under any

circumstance. Indicate whether the statement is true or false.

Biology & Microbiology