BIOLOGY REINFORCEMENT TEST 2B EXPLANATIONS
The question stem asks you to correctly match the organisms with their classification in the food
Lettuce is the primary producer because it is a green plant that uses the energy of the sun to
manufacture carbohydrates, proteins, and lipids.
The mouse is a primary consumer because it feeds on
primary producers (green plants).
The snake is a secondary consumer because it feeds on primary
consumers, such as mice.
is considered to be a decomposer because it breaks down organic
wastes and dead tissues to basic compounds.
Thus, choice C is the correct answer because it correctly
matches the organisms with their classification on the food chain.
ADH (antidiuretic hormone) is produced by neurosecretory cells in the hypothalamus and is
stored and released by the posterior pituitary.
ADH is responsible for increasing the permeability of the
nephron’s distal tubule and collecting duct to water, thereby promoting water reabsorption and increasing
Choices B, C, and D are all incorrect because TSH, ACTH, and FSH are all released by the
ACTH stimulates the adrenal cortex to synthesize and secrete glucocorticoids.
stimulates the thyroid gland to synthesize and secrete thyroxine, and FSH causes maturation of ovarian
During the first trimester of pregnancy, the corpus luteum is preserved by human chorionic
gonadotropin (HCG)—a hormone produced by the blastocyst and the developing placenta.
luteum secretes estrogen and progesterone, which maintain a healthy endometrium for the developing
The high levels of estrogen and progesterone simultaneously inhibit the release of FSH and LH,
preventing further ovulation.
Choice B is incorrect because HCG does not stimulate the anterior pituitary to secrete
Choice C is incorrect because HCG does not directly inhibit GnRH.
HCG preserves the
corpus luteum, which continues to secrete progesterone and estrogen.
High levels of estrogen and
progesterone inhibit GnRH.
Thus, choice C is incorrect.
Choice D is incorrect because HCG preserves
the corpus luteum, not the follicle.
Carbon monoxide is lethal because it has a stronger affinity for hemoglobin than does oxygen.
Thus, the carbon monoxide will preferentially replace oxygen on hemoglobin, so hemoglobin will not be
able to deliver oxygen to the body tissues, and death could result.
Red blood cells have characteristic cell-surface proteins (antigens) by which the blood can be
classified. One of the major groups of blood antigens is the ABO system. In the ABO system, an
individual can have the A antigen (type A), the B antigen (type B), both antigens (type AB), or neither
antigen (type O) present on his or her red blood cells. The plasma of every individual contains antibodies,