HESI A2 Biology practice Questions With Complete
Solutions
A pea plant has alleles for the dominant tall gene (T) and the
recessive short gene (t). Therefore, it appears as Tt. Which of the
following will correctly describe its phenotype if there is
complete dominance? And which describes incomplete
dominance? (complete, incomplete)
a. Tall, Tall
b. Average. Tall
c. Tall, Average
d. Tall, Short Correct Answer - Tall, Average
Question 33 Explanation:
Because the dominant allele is present, this pea plant will be tall
despite its recessive gene in complete dominance. In Incomplete
dominance however, the gene must be homozygous to show one
trait. Otherwise the phenotype will be a mixture of the two
alleles.
A scientist conducts an experiment to discover the effect of
music on plant growth. He hypothesizes that the music will help
plants grow at a faster rate than plants without music. By the end
of the experiment, plants grown with music playing grew to an
average height of 5.6 inches, while plants grown without music
playing grew to an average height of 2.3 inches. Which of the
following is the scientist's correct conclusion?
A. All plants grow better with music.
,B. In the experiment, plants grown with music grew better than
those grown without it.
C. In the experiment, plants grown without music grew better
than those grown without it.
D. All plants grow better without music. Correct Answer - In
the experiment, plants grown with music grew better than those
grown without it.
Question 36 Explanation:
This is the correct conclusion to draw from this experiment. "All
plants" is too general a term. The data supports the conclusion
that music aided growth.
A scientist is proposing an experiment to study the effect of a
certain chemical on rat brain development. The scientist believes
that this chemical will enhance the rats' brain development.
Which of the following terms describes this step of the scientific
process?
a. Hypothesis.
b. Experiment.
c. Analysis.
d. Conclusion. Correct Answer - Hypothesis
Question 26 Explanation:
The scientist has formed a hypothesis, a statement of certain
events or happenings, and is ready to conduct his experiment.
Analysis is not a step in the scientific method.
Active transport
,(carrier-mediated transport) Correct Answer - the movement of
substances against the concentration gradient, from low to high
concentration, with the aid of carrier proteins; requires energy
Active transport Correct Answer - movement of substances
across a cell membrane requiring energy to be expended by the
cell
- is the movement of molecules from an area of lower
concentration to an area of higher concentration. It occurs across
cell membranes.
adrenocorticotroic hormone Correct Answer - helps reduce
stress
Afferent neurons Correct Answer Send sensory signals to the
central nervous system
- sensory
All genes can be described using the Punnett Square method.
True or False?
A. True
B. False Correct Answer - False
Question 19 Explanation:
False. There are many more complicated forms of genetic
expression available than the simple genetics represented by the
Punnett Square.
All living organisms on Earth utilize: Correct Answer A triplet
genetic code
, Amphiarthroses (joints) Correct Answer - allow a slight
amount of movement
An organism that has a genotype of two dominant alleles for one
gene is:
A. Heterozygous.
B. Homozygous.
C. Multiparous.
D. Nulliparous Correct Answer - Homozygous
Question 16 Explanation:
When an organism possesses the same type of alleles for one
gene, it is homozygous. The prefix homo- indicates same, and
the prefix hetero- indicates different.
antidiuretic hormone (ADH) Correct Answer - helps regulate
the body's water balance
axon Correct Answer - transmit nerve impulses away from the
cell body
Based on the inherent properties of water molecules, what effect
would a large body of water have on the temperature of a
climate?
A. Increase.
B. Decrease.
C. Stabilize.
D. Destabilize. Correct Answer - Stabilize.
Solutions
A pea plant has alleles for the dominant tall gene (T) and the
recessive short gene (t). Therefore, it appears as Tt. Which of the
following will correctly describe its phenotype if there is
complete dominance? And which describes incomplete
dominance? (complete, incomplete)
a. Tall, Tall
b. Average. Tall
c. Tall, Average
d. Tall, Short Correct Answer - Tall, Average
Question 33 Explanation:
Because the dominant allele is present, this pea plant will be tall
despite its recessive gene in complete dominance. In Incomplete
dominance however, the gene must be homozygous to show one
trait. Otherwise the phenotype will be a mixture of the two
alleles.
A scientist conducts an experiment to discover the effect of
music on plant growth. He hypothesizes that the music will help
plants grow at a faster rate than plants without music. By the end
of the experiment, plants grown with music playing grew to an
average height of 5.6 inches, while plants grown without music
playing grew to an average height of 2.3 inches. Which of the
following is the scientist's correct conclusion?
A. All plants grow better with music.
,B. In the experiment, plants grown with music grew better than
those grown without it.
C. In the experiment, plants grown without music grew better
than those grown without it.
D. All plants grow better without music. Correct Answer - In
the experiment, plants grown with music grew better than those
grown without it.
Question 36 Explanation:
This is the correct conclusion to draw from this experiment. "All
plants" is too general a term. The data supports the conclusion
that music aided growth.
A scientist is proposing an experiment to study the effect of a
certain chemical on rat brain development. The scientist believes
that this chemical will enhance the rats' brain development.
Which of the following terms describes this step of the scientific
process?
a. Hypothesis.
b. Experiment.
c. Analysis.
d. Conclusion. Correct Answer - Hypothesis
Question 26 Explanation:
The scientist has formed a hypothesis, a statement of certain
events or happenings, and is ready to conduct his experiment.
Analysis is not a step in the scientific method.
Active transport
,(carrier-mediated transport) Correct Answer - the movement of
substances against the concentration gradient, from low to high
concentration, with the aid of carrier proteins; requires energy
Active transport Correct Answer - movement of substances
across a cell membrane requiring energy to be expended by the
cell
- is the movement of molecules from an area of lower
concentration to an area of higher concentration. It occurs across
cell membranes.
adrenocorticotroic hormone Correct Answer - helps reduce
stress
Afferent neurons Correct Answer Send sensory signals to the
central nervous system
- sensory
All genes can be described using the Punnett Square method.
True or False?
A. True
B. False Correct Answer - False
Question 19 Explanation:
False. There are many more complicated forms of genetic
expression available than the simple genetics represented by the
Punnett Square.
All living organisms on Earth utilize: Correct Answer A triplet
genetic code
, Amphiarthroses (joints) Correct Answer - allow a slight
amount of movement
An organism that has a genotype of two dominant alleles for one
gene is:
A. Heterozygous.
B. Homozygous.
C. Multiparous.
D. Nulliparous Correct Answer - Homozygous
Question 16 Explanation:
When an organism possesses the same type of alleles for one
gene, it is homozygous. The prefix homo- indicates same, and
the prefix hetero- indicates different.
antidiuretic hormone (ADH) Correct Answer - helps regulate
the body's water balance
axon Correct Answer - transmit nerve impulses away from the
cell body
Based on the inherent properties of water molecules, what effect
would a large body of water have on the temperature of a
climate?
A. Increase.
B. Decrease.
C. Stabilize.
D. Destabilize. Correct Answer - Stabilize.
