9) the hormone produced by cells around the embryo that maintains the corpus luteum
and pregnancy is called
a. estrogen.
b. progesterone.
c. luteinizing hormone (lh).
d. follicle-stimulating hormone (fsh).
e. human chorionic gonadotropin (hcg).
10) some biologists study the complex interactions of animals and plants in forests or
prairies. such ecology field research often produces slightly different results for
different researchers. in contrast, ecology experiments that are run indoors with one
organism in a terrarium usually produce results that are repeatable. what is the most
likely explanation?
a. the scientific method is only useful in laboratory settings.
b. it is not possible to establish a control group outside of a laboratory.
c. it is easier to hold all but one variable constant in a laboratory.
d. field research is only descriptive, and descriptive research is not strictly ‘science.”
e. fieldwork is inductive; lab work is deductive.
11) which type of blood component is involved in the initiation of clotting?
a. red blood cells
b. white blood cells
c. plasma proteins
d. platelets
12) which value of biodiversity in an ecosystem will benefit endangered species the
most?
a. consumptive value