Mammals nourish their embryos by means of a ____

a. placenta
b. uterus
c. yolk sac
d. blastocyst
e. amnion


ANSWER: a

Biology & Microbiology

You might also like to view...

During the light reaction water is oxidized to form oxygen. This process

A. yields low-energy electrons. B. yields high-energy electrons. C. is needed to replace the electron lost by P680 during the light reaction. D. yields low-energy electrons and is needed to replace the electron lost by P680 during the light reaction. E. yields high-energy electrons and is needed to replace the electron lost by P680 during the light reaction.

Biology & Microbiology

When salt dissolves in water, the water molecules form ____ around the Na+ and Cl- ions

a. covalent bonds b. hydration layers c. nonpolar interactions d. membranes e. ionic bonds

Biology & Microbiology

Which of the following drugs has been discovered to bind to acetylcholine receptors?  

A.  serotonin reuptake inhibitors B.  thorazine C.  cocaine D.  codeine E.  nicotine

Biology & Microbiology

Genetic recombination as a result of crossing over

occurs more readily in genes a. that are on the sex chromosomes. b. that are on the autosomes. c. that are located close together on the same chromosome. d. that are located far apart on the same chromosome. e. that are located on different chromosomes.

Biology & Microbiology