BIO 189 MIDTERM EXAM STUDY GUIDE
2025/2026 COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS WITH
RATIONALES || 100% GUARANTEED PASS
<RECENT VERSION>
1. Why do scientists typically design experiments that will yield quantitative
results? - ANSWER ✓ Quantitative results minimize the potential for bias.
2. What is a characteristic of eukaryotes? - ANSWER ✓ Their DNA is
contained in a nucleus.
3. Scientists perform ____ in order to ____ a given ____. - ANSWER ✓
experiments; test; hypothesis
4. What practice helps scientists avoid bias in their findings? - ANSWER ✓
designing experiments that yield quantitative results
5. What name is given to the scientific study of life? - ANSWER ✓ biology
6. Which of the following represents the most correct order of the organization
of life from the smallest unit to the largest? - ANSWER ✓ atoms ®
molecules ® cells ® organisms ® populations ® communities ® ecosystems
® biosphere
7. Which of the following characteristics are shared by all living organisms?
I.
hereditary information is passed to offspring
II.
adaptation to environmental change
III.
requirement for nutrients
IV.
, DNA housed in a nucleus - ANSWER ✓ I, II, and III
8. Which of the following organization levels is the least inclusive? -
ANSWER ✓ atom
9. In the scientific name, Pan paniscus, Pan represents the name of the ____,
while paniscus represents the name of the ____. - ANSWER ✓ genus;
species
10.If a hypothesis stands after years of repeated testing, is consistent with all
data gathered, and helps make successful predictions about other
phenomena, it is considered to be a ____. - ANSWER ✓ scientific theory
11.A triglyceride molecule is made up of ____. - ANSWER ✓ one glycerol and
three fatty acids
12.Which of the following best describes the structure of a biological
membrane
A. two layers of phospholipids (with opposite orientations of the
phospholipids in each layer) with each layer covered on the outside
with proteins
B. a fluid structure in which phospholipids and proteins move freely
between sides of the membrane
C. a mixture of covalently linked phospholipids and proteins that
determines which solutes can cross the membrane and which cannot
D. two layers of phospholipids with proteins embedded between the two
layers
E. two layers of phospholipids with proteins either crossing the layers or
on the surface of the layers - ANSWER ✓ E. two layers of
phospholipids with proteins either crossing the layers or on the surface
of the layers
13.Which of the following is a reasonable explanation for why unsaturated fatty
acids help keep any membrane more fluid at lower temperature?
A. The double bonds form kinks in the fatty acid tail, forcing adjacent
lipids to be further apart.
, B. Unsaturated fatty acids have a higher cholesterol content and therefore
more cholesterol in their membranes.
C. Unsaturated fatty acids are more polar than saturated fatty acids.
D. The double bonds block interaction among the hydrophilic head
groups of the lipids.
E. The double bonds result in shorter fatty acid tails and thinner
membranes. - ANSWER ✓ A. The double bonds form kinks in the
fatty acid tail, forcing adjacent lipids to be further apart.
14.Celery stalks that are immersed in fresh water for several hours become stiff
and hard. Similar stalks left in a 0.15 M salt solution become limp and soft.
From this we can deduce that
A. The fresh water is hypotonic & the salt solution is hypertonic to the
cells of the celery stalks
B. the fresh water is hypertonic and the salt solution is hypotonic to the
cells of the celery stalks.
C. the fresh water and the salt solution are both hypotonic to the cells of
the celery stalks.
D. the fresh water is isotonic and the salt solution is hypertonic to the
cells of the celery stalks.
E. the fresh water and the salt solution are both hypertonic to the cells of
the celery stalks. - ANSWER ✓ A. The fresh water is hypotonic & the
salt solution is hypertonic to the cells of the celery stalks
15.Which of the following statements about osmosis is correct?
A. Osmotic movement of water into a cell would likely occur if the cell
accumulates water from its environment
B. Osmosis is the diffusion of water from a region of lower water
concentration to a region of higher water concentration
C. The presence of aquaporins (proteins that form water channels in the
membrane) should speed up the process of osmosis.
D. If a cell is placed in an isotonic solution, more water will enter the cell
than leaves the cell.
E. If a solution outside the cell is hypertonic compared to the cytoplasm,
water will move into the cell by osmosis - ANSWER ✓ C. The
presence of aquaporins (proteins that form water channels in the
membrane) should speed up the process of osmosis.
, (Aquaporins facilitate water movement across membranes and thus speed up
the process of osmosis.)
16.The solutions in the arms of a U-tube are separated at the bottom of the tube
by a selectively permeable membrane. The membrane is permeable to
sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M
glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a
solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the
volume in both arms is the same. Refer to the figure to answer the following
question.
17.If you examine side A after three days, you should find
A. No net change in the system
B. a decrease in the concentration of NaCl, an increase in water level,
and no change in the concentration of glucose.
C. a decrease in the concentration of NaCl and glucose and an increase in
the water level.
D. no change in the concentration of NaCl and glucose and an increase in
the water level.
E. a decrease in the concentration of NaCl and a decrease in the water
level. - ANSWER ✓ E. A decrease in the concentration of NaCl and a
decrease in the water level
18.The difference between pinocytosis and receptor-mediator endocytosis is
that
A) pinocytosis brings only water molecules into the cell, but
receptor-mediated endocytosis brings in other molecules as
well.
B) pinocytosis increases the surface area of the plasma
membrane, whereas receptor-mediated endocytosis decreases
the plasma membrane surface area.
C) pinocytosis is nonselective in the molecules it brings into the
cell, whereas receptor-mediated endocytosis offers more
selectivity.
D) pinocytosis can concentrate substances from the extracellular
fluid, but receptor-mediated endocytosis cannot. - ANSWER
2025/2026 COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS WITH
RATIONALES || 100% GUARANTEED PASS
<RECENT VERSION>
1. Why do scientists typically design experiments that will yield quantitative
results? - ANSWER ✓ Quantitative results minimize the potential for bias.
2. What is a characteristic of eukaryotes? - ANSWER ✓ Their DNA is
contained in a nucleus.
3. Scientists perform ____ in order to ____ a given ____. - ANSWER ✓
experiments; test; hypothesis
4. What practice helps scientists avoid bias in their findings? - ANSWER ✓
designing experiments that yield quantitative results
5. What name is given to the scientific study of life? - ANSWER ✓ biology
6. Which of the following represents the most correct order of the organization
of life from the smallest unit to the largest? - ANSWER ✓ atoms ®
molecules ® cells ® organisms ® populations ® communities ® ecosystems
® biosphere
7. Which of the following characteristics are shared by all living organisms?
I.
hereditary information is passed to offspring
II.
adaptation to environmental change
III.
requirement for nutrients
IV.
, DNA housed in a nucleus - ANSWER ✓ I, II, and III
8. Which of the following organization levels is the least inclusive? -
ANSWER ✓ atom
9. In the scientific name, Pan paniscus, Pan represents the name of the ____,
while paniscus represents the name of the ____. - ANSWER ✓ genus;
species
10.If a hypothesis stands after years of repeated testing, is consistent with all
data gathered, and helps make successful predictions about other
phenomena, it is considered to be a ____. - ANSWER ✓ scientific theory
11.A triglyceride molecule is made up of ____. - ANSWER ✓ one glycerol and
three fatty acids
12.Which of the following best describes the structure of a biological
membrane
A. two layers of phospholipids (with opposite orientations of the
phospholipids in each layer) with each layer covered on the outside
with proteins
B. a fluid structure in which phospholipids and proteins move freely
between sides of the membrane
C. a mixture of covalently linked phospholipids and proteins that
determines which solutes can cross the membrane and which cannot
D. two layers of phospholipids with proteins embedded between the two
layers
E. two layers of phospholipids with proteins either crossing the layers or
on the surface of the layers - ANSWER ✓ E. two layers of
phospholipids with proteins either crossing the layers or on the surface
of the layers
13.Which of the following is a reasonable explanation for why unsaturated fatty
acids help keep any membrane more fluid at lower temperature?
A. The double bonds form kinks in the fatty acid tail, forcing adjacent
lipids to be further apart.
, B. Unsaturated fatty acids have a higher cholesterol content and therefore
more cholesterol in their membranes.
C. Unsaturated fatty acids are more polar than saturated fatty acids.
D. The double bonds block interaction among the hydrophilic head
groups of the lipids.
E. The double bonds result in shorter fatty acid tails and thinner
membranes. - ANSWER ✓ A. The double bonds form kinks in the
fatty acid tail, forcing adjacent lipids to be further apart.
14.Celery stalks that are immersed in fresh water for several hours become stiff
and hard. Similar stalks left in a 0.15 M salt solution become limp and soft.
From this we can deduce that
A. The fresh water is hypotonic & the salt solution is hypertonic to the
cells of the celery stalks
B. the fresh water is hypertonic and the salt solution is hypotonic to the
cells of the celery stalks.
C. the fresh water and the salt solution are both hypotonic to the cells of
the celery stalks.
D. the fresh water is isotonic and the salt solution is hypertonic to the
cells of the celery stalks.
E. the fresh water and the salt solution are both hypertonic to the cells of
the celery stalks. - ANSWER ✓ A. The fresh water is hypotonic & the
salt solution is hypertonic to the cells of the celery stalks
15.Which of the following statements about osmosis is correct?
A. Osmotic movement of water into a cell would likely occur if the cell
accumulates water from its environment
B. Osmosis is the diffusion of water from a region of lower water
concentration to a region of higher water concentration
C. The presence of aquaporins (proteins that form water channels in the
membrane) should speed up the process of osmosis.
D. If a cell is placed in an isotonic solution, more water will enter the cell
than leaves the cell.
E. If a solution outside the cell is hypertonic compared to the cytoplasm,
water will move into the cell by osmosis - ANSWER ✓ C. The
presence of aquaporins (proteins that form water channels in the
membrane) should speed up the process of osmosis.
, (Aquaporins facilitate water movement across membranes and thus speed up
the process of osmosis.)
16.The solutions in the arms of a U-tube are separated at the bottom of the tube
by a selectively permeable membrane. The membrane is permeable to
sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M
glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a
solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the
volume in both arms is the same. Refer to the figure to answer the following
question.
17.If you examine side A after three days, you should find
A. No net change in the system
B. a decrease in the concentration of NaCl, an increase in water level,
and no change in the concentration of glucose.
C. a decrease in the concentration of NaCl and glucose and an increase in
the water level.
D. no change in the concentration of NaCl and glucose and an increase in
the water level.
E. a decrease in the concentration of NaCl and a decrease in the water
level. - ANSWER ✓ E. A decrease in the concentration of NaCl and a
decrease in the water level
18.The difference between pinocytosis and receptor-mediator endocytosis is
that
A) pinocytosis brings only water molecules into the cell, but
receptor-mediated endocytosis brings in other molecules as
well.
B) pinocytosis increases the surface area of the plasma
membrane, whereas receptor-mediated endocytosis decreases
the plasma membrane surface area.
C) pinocytosis is nonselective in the molecules it brings into the
cell, whereas receptor-mediated endocytosis offers more
selectivity.
D) pinocytosis can concentrate substances from the extracellular
fluid, but receptor-mediated endocytosis cannot. - ANSWER
