CLEP Biology Practice Test 1
Questions With 100% Correct/Verified
Solutions 2026 Updated.
Two organisms that are classified in the same family would not necessarily be classified in the
same
a) kingdom
b) order
c) phylum
d) class
e) genus - Answer e) genus
Because a "family" is more highly classified than kingdom, phylum, class, and order, organisms
that share the same family must also share the same kingdom, phylum, class, and order. Only
the genus of the two organisms may differ.
Plasma B cells are essential in the human immune response because of their ability to
a) produce antibodies that can clump bacteria or viruses together so that macrophages can
ingest them.
b) attach directly to infected cells and puncture them with enzymes.
c) cause antigen molecules, such as toxins, to settle out of the blood plasma.
d) engulf pathogens that they encounter in the bloodstream.
e) clot open wounds so that bacteria cannot invade the body. - Answer a) produce
antibodies that can clump bacteria or viruses together so that macrophages can ingest them.
Plasma B cells are specialized immune system cells that secrete antibodies, small Y-shaped
proteins that can directly attach to and agglutinate, or clump, invading bacteria. Attaching
directly to cells is the job of killerT cells, and engulfing pathogens is the job of macrophages.
Clotting is done primarily by platelets and other protein fibers.
The first vertebrates to live on land were the amphibians, characterized by their ability to
a) lay eggs and by their rough, scaly skin.
b) breathe through moist skin and walk on four limbs.
c) lay hard-shelled eggs on land.
d) run quickly on land using muscular limbs.
e) develop mammary glands for milk production. - Answer b) breathe through moist skin and
walk on four limbs.
,Amphibians are characterized by their ability to breathe through moist skin (in addition to small
lungs) and to walk on four limbs. They do not have rough, scaly skin or lay hard-shelled eggs like
their reptile descendants, nor can they run quickly on land with muscular limbs (also like
reptiles). Mammals are set apart by their milk-producing abilities.
Fossils of an ancient reptile called Lystrosaurus have been found in Africa, India, and Antarctica.
Which of the following best explains this distribution?
a) They were able to move between continents before the oceans filled.
b) The movement of India due to continental drift carried them from place to place.
c) These land areas were once next to each other and have since drifted apart.
d) They were able to migrate over frozen seas during Ice Ages.
e) Changes in climate forced them to migrate from place to place. - Answer c) These land
areas were once next to each other and have since drifted apart.
The best evidence to support the finding of fossils on widely separated land masses comes from
continental drift theory, which states that certain land areas had been connected and slowly
drifted apart—this would allow for separation of what were once continuous species' ranges. It
is highly unlikely that a reptile species could have moved easily between continents or could
have survived frozen seas during the Ice Ages.
Gregor Mendel identified "factors" that could be passed down from parents to offspring and
that resulted in the expression of certain characteristics. Today, we call Mendel's "factors"
a) linked genes. b) alleles. c) genotypes. d) phenotypes. e) homologous chromosomes. - Answer
b) alleles
Different forms of the same gene are called alleles. For example, B (brown) and b (blue) are two
different possible eye color alleles in humans. No other answer choices fit the definition of a
"factor" that results in the expression of a certain characteristic.
A decrease in the amount of carbon dioxide present in the air surrounding most plants would
most likely result in
a) the death of the plants.
b) an increase in the production of sugars through photosynthesis.
c) a decrease in the output of the Calvin cycle.
d) the breakdown of chlorophyll molecules in the mesophyll layer.
e) more nitrogen released into the air from the soil. - Answer c) a decrease in the output of
the Calvin cycle.
,Carbon dioxide is needed in the Calvin cycle to produce sugars, and there is no connection
between the Calvin cycle and the building of nitrogen-producing compounds by a plant. The
decrease in carbon dioxide would most likely not result in the plant's death, but it might hurt
the plant by decreasing its ability to produce sugars. Chlorophyll molecules should be
unaffected.
Fertilization of a human ovum normally occurs in the
a) vagina.
b) ovary.
c) uterus.
d) seminiferous tubule.
e) oviduct. - Answer e) oviduct.
The oviduct, or fallopian tube, is the usual site of fertilization of the ovum. It is here, after being
released from the ovary, that an egg is most likely to meet sperm cells coming up from the
vagina
A DNA strand has a base sequence of CGTAGT. The mRNA strand transcribed from this DNA is
a) ACUACG
b) CGTAGT
c) GCAUCA
d) GACUAC
e) UACGUA - Answer c) GCAUCA
When DNA is transcribed into messenger RNA, the basepairings are complementary but not
identical. In addition, RNA has no thymine (T), only uracil (U). Thus, the correct complementary
pairing would be A's with U's, T's with A's, and C's with G's or CGTAGT → GCAUCA.
Diabetics may have sugar in their urine because
a) the proximal tubules of their nephrons cannot reabsorb sugar efficiently.
b) they do not produce enough insulin to absorb sugar from the bloodstream. c) of deamination
of proteins in their cells.
d) poor filtration at the Bowman's capsules of their nephrons.
e) they eat large amounts of sugar. - Answer b) they do not produce enough insulin to
absorb sugar from the bloodstream.
Diabetics may suffer from a buildup of sugar in their bloodstream because their bodies produce
too little insulin (which is normally responsible for pulling sugar out of the bloodstream and into
cells) and/or their body's response to insulin is reduced (a condition known as insulin
, resistance). Although the disease may cause damage to the kidneys eventually, the disease is
not caused by any kidney malfunction.
Damage to the cells lining the large intestine would likely result in
a) diarrhea.
b) decreased absorption of sugars and lipids.
c) decreased filtration of proteins and amino acids from the bloodstream.
d) heartburn.
e) gallstones. - Answer a) diarrhea
The large intestine is responsible for the absorption of salts and water from the digestive
system. If damaged, excess water can remain in the digestive tract and cause watery stools, or
diarrhea.
The area of this cell in which a chemiosmotic hydrogen-ion gradient is used to produce ATP is
represented by the letter
IMAGE NEEDED
a) A
b) C
c) F
d) G
e) H - Answer b) C
The mitochondrion is the organelle in which ATP is produced in eukaryotic cells. Most cells have
multiple mitochondria to serve their energy needs. The letter C here points to a single
mitochondrion within this cell.
The following data are collected from placing three lizards of different species in separate closed
tanks to measure their production of carbon dioxide over the course of 30 minutes. Which of
the following conclusions can be accurately drawn from this data?
IMAGE NEEDED
a) Lizards with smaller bodies consumed less oxygen per gram of body weight than lizards with
larger bodies.
b) Each species of lizard has a unique rate of respiration.
Questions With 100% Correct/Verified
Solutions 2026 Updated.
Two organisms that are classified in the same family would not necessarily be classified in the
same
a) kingdom
b) order
c) phylum
d) class
e) genus - Answer e) genus
Because a "family" is more highly classified than kingdom, phylum, class, and order, organisms
that share the same family must also share the same kingdom, phylum, class, and order. Only
the genus of the two organisms may differ.
Plasma B cells are essential in the human immune response because of their ability to
a) produce antibodies that can clump bacteria or viruses together so that macrophages can
ingest them.
b) attach directly to infected cells and puncture them with enzymes.
c) cause antigen molecules, such as toxins, to settle out of the blood plasma.
d) engulf pathogens that they encounter in the bloodstream.
e) clot open wounds so that bacteria cannot invade the body. - Answer a) produce
antibodies that can clump bacteria or viruses together so that macrophages can ingest them.
Plasma B cells are specialized immune system cells that secrete antibodies, small Y-shaped
proteins that can directly attach to and agglutinate, or clump, invading bacteria. Attaching
directly to cells is the job of killerT cells, and engulfing pathogens is the job of macrophages.
Clotting is done primarily by platelets and other protein fibers.
The first vertebrates to live on land were the amphibians, characterized by their ability to
a) lay eggs and by their rough, scaly skin.
b) breathe through moist skin and walk on four limbs.
c) lay hard-shelled eggs on land.
d) run quickly on land using muscular limbs.
e) develop mammary glands for milk production. - Answer b) breathe through moist skin and
walk on four limbs.
,Amphibians are characterized by their ability to breathe through moist skin (in addition to small
lungs) and to walk on four limbs. They do not have rough, scaly skin or lay hard-shelled eggs like
their reptile descendants, nor can they run quickly on land with muscular limbs (also like
reptiles). Mammals are set apart by their milk-producing abilities.
Fossils of an ancient reptile called Lystrosaurus have been found in Africa, India, and Antarctica.
Which of the following best explains this distribution?
a) They were able to move between continents before the oceans filled.
b) The movement of India due to continental drift carried them from place to place.
c) These land areas were once next to each other and have since drifted apart.
d) They were able to migrate over frozen seas during Ice Ages.
e) Changes in climate forced them to migrate from place to place. - Answer c) These land
areas were once next to each other and have since drifted apart.
The best evidence to support the finding of fossils on widely separated land masses comes from
continental drift theory, which states that certain land areas had been connected and slowly
drifted apart—this would allow for separation of what were once continuous species' ranges. It
is highly unlikely that a reptile species could have moved easily between continents or could
have survived frozen seas during the Ice Ages.
Gregor Mendel identified "factors" that could be passed down from parents to offspring and
that resulted in the expression of certain characteristics. Today, we call Mendel's "factors"
a) linked genes. b) alleles. c) genotypes. d) phenotypes. e) homologous chromosomes. - Answer
b) alleles
Different forms of the same gene are called alleles. For example, B (brown) and b (blue) are two
different possible eye color alleles in humans. No other answer choices fit the definition of a
"factor" that results in the expression of a certain characteristic.
A decrease in the amount of carbon dioxide present in the air surrounding most plants would
most likely result in
a) the death of the plants.
b) an increase in the production of sugars through photosynthesis.
c) a decrease in the output of the Calvin cycle.
d) the breakdown of chlorophyll molecules in the mesophyll layer.
e) more nitrogen released into the air from the soil. - Answer c) a decrease in the output of
the Calvin cycle.
,Carbon dioxide is needed in the Calvin cycle to produce sugars, and there is no connection
between the Calvin cycle and the building of nitrogen-producing compounds by a plant. The
decrease in carbon dioxide would most likely not result in the plant's death, but it might hurt
the plant by decreasing its ability to produce sugars. Chlorophyll molecules should be
unaffected.
Fertilization of a human ovum normally occurs in the
a) vagina.
b) ovary.
c) uterus.
d) seminiferous tubule.
e) oviduct. - Answer e) oviduct.
The oviduct, or fallopian tube, is the usual site of fertilization of the ovum. It is here, after being
released from the ovary, that an egg is most likely to meet sperm cells coming up from the
vagina
A DNA strand has a base sequence of CGTAGT. The mRNA strand transcribed from this DNA is
a) ACUACG
b) CGTAGT
c) GCAUCA
d) GACUAC
e) UACGUA - Answer c) GCAUCA
When DNA is transcribed into messenger RNA, the basepairings are complementary but not
identical. In addition, RNA has no thymine (T), only uracil (U). Thus, the correct complementary
pairing would be A's with U's, T's with A's, and C's with G's or CGTAGT → GCAUCA.
Diabetics may have sugar in their urine because
a) the proximal tubules of their nephrons cannot reabsorb sugar efficiently.
b) they do not produce enough insulin to absorb sugar from the bloodstream. c) of deamination
of proteins in their cells.
d) poor filtration at the Bowman's capsules of their nephrons.
e) they eat large amounts of sugar. - Answer b) they do not produce enough insulin to
absorb sugar from the bloodstream.
Diabetics may suffer from a buildup of sugar in their bloodstream because their bodies produce
too little insulin (which is normally responsible for pulling sugar out of the bloodstream and into
cells) and/or their body's response to insulin is reduced (a condition known as insulin
, resistance). Although the disease may cause damage to the kidneys eventually, the disease is
not caused by any kidney malfunction.
Damage to the cells lining the large intestine would likely result in
a) diarrhea.
b) decreased absorption of sugars and lipids.
c) decreased filtration of proteins and amino acids from the bloodstream.
d) heartburn.
e) gallstones. - Answer a) diarrhea
The large intestine is responsible for the absorption of salts and water from the digestive
system. If damaged, excess water can remain in the digestive tract and cause watery stools, or
diarrhea.
The area of this cell in which a chemiosmotic hydrogen-ion gradient is used to produce ATP is
represented by the letter
IMAGE NEEDED
a) A
b) C
c) F
d) G
e) H - Answer b) C
The mitochondrion is the organelle in which ATP is produced in eukaryotic cells. Most cells have
multiple mitochondria to serve their energy needs. The letter C here points to a single
mitochondrion within this cell.
The following data are collected from placing three lizards of different species in separate closed
tanks to measure their production of carbon dioxide over the course of 30 minutes. Which of
the following conclusions can be accurately drawn from this data?
IMAGE NEEDED
a) Lizards with smaller bodies consumed less oxygen per gram of body weight than lizards with
larger bodies.
b) Each species of lizard has a unique rate of respiration.
