HESI A2 V2 BIOLOGY EXAM WITH VERIFIED SOLUTIONS AND EXPLANATIONS

HESI A2 V2 BIOLOGY EXAM WITH VERIFIED
SOLUTIONS AND EXPLANATIONS

The movement of a substance across a cell
membrane from low to high concentration is
known as what?
a. Passive transport
b. Diffusion
c. Active transport
d. Facilitated diffusion - ANSWER-- Active
transport
Active transport is the movement of molecules
against their concentration gradient, such as
when moving from low to high concentration.
Which of the following is NOT a part of the
body's chemical defense system against
infection?
a. Urine
b. Hydrochloric acid
c. Agranulocyte
d. Lysozyme - ANSWER-- Agranulocytes
Agranulocytes are a type of white blood cell and
therefore are not a part of the body's chemical
defense system.
Positive feedback is a mechanism used by the
body that results in amplification or
enhancement of a signal that has already been
activated. An example of this would be:
a. Slowing metabolism in response to starvation
b. Shivering to increase temperature
c. Blood vessels regulating blood pressure
d. The release of oxytocin to increase
contractions during childbirth - ANSWER-- The
release of oxytocin to increase contractions
during childbirth
Contractions in childbirth are considered a
positive feedback loop because each
contraction stimulates the brain to release more
Oxytocin, which in turn stimulates more
contractions.
When placed in a hypotonic solution, a cell will
do which of the following?
a. Remain the same
b. Disintegrate
c. Swell
d. Shrink - ANSWER-- swell
Water always moves from areas of higher
concentration to lower concentration. A
hypotonic solution contains less solutes and
more water then the contents inside of the cell,
so water will move from outside of the cell to
inside, causing it to swell.
Which is NOT an effect of photo-oxidation?
a. Increase in tensile strength
b. Discoloration
c. Increase in brittleness
d. Loss of surface smoothness - ANSWER--
Increase in tensile strength
Photo-oxidation occurs when UV light and
ozone break down the surface of polymers. The
result is the material becoming more brittle and
discolored and less strong and smooth.
Which of the following is considered an
example of naturally acquired passive
immunity?
a. Attenuated (live) vaccine injection
b. Breastfeeding
c. Inactivated (killed) vaccine injection
d. Exposure to a disease and subsequent
immunity - ANSWER-- breastfeeding
Natural passive immunity occurs when live
antibodies are transferred from one individual to
another, such as when anti-bodies are
transferred from a mother to her baby via breast
milk.
Worms lack which of the following?
a. Eyes and brain
b. Brain
c. Eyes
d. Nerve centers - ANSWER-- eyes and brain
Worms lack both eyes and a brain, but they do
have nerve centers.