DAT Biology Exam 2026 | High-Yield Practice Questions &
Verified Answers | Complete Dental Admission Test Prep
1. What type of bonds connect the base pairs in the DNA structure?
Covalent bonds
Peptide bonds
Hydrogen bonds
Ionic bonds
2. Describe how mutualism differs from parasitism in ecological
interactions.
Mutualism benefits both species involved, while parasitism
benefits one species at the expense of the other.
Mutualism involves competition between species, while
parasitism involves cooperation.
Mutualism occurs only in plants, while parasitism occurs in
animals.
Mutualism is harmful to both species, while parasitism is
beneficial to both.
3. Describe the initial stages of secondary succession and the types of
organisms that typically establish first.
Secondary succession involves the immediate return of all
original species.
Secondary succession starts with the growth of trees in a
completely barren area.
Secondary succession occurs only after a volcanic eruption.
Secondary succession begins with the establishment of shrubs
after a small disturbance.
,4. A bat wing and a human arm are said to be homologous structure. This
indicates that...
They have the same function
They are structures which are similar due to common ancestry
They have a different ancestry but a common function
The limb bones of each are anatomically identical
5. What is the definition of genetic drift?
A change in allele frequencies due to random sampling effects
A mechanism of evolution involving mutations
The movement of alleles between populations
A process of natural selection favoring certain traits
6. In a hypothetical population of birds where both very small and very
large beaks are favored due to food availability, what evolutionary
outcome might result from disruptive selection over several
generations?
Speciation
Extinction of the population
Increased competition
Stabilization of average beak size
7. If the notochord fails to develop properly during embryonic
development, what potential outcome could occur regarding the neural
tube?
Improper limb formation
Enhanced cognitive function
, Increased skin sensitivity
Neural tube defects
8. Describe the significance of dNTPs in the process of DNA replication.
dNTPs are essential for DNA replication as they provide the
necessary nucleotides for synthesizing new DNA strands.
dNTPs are used to repair damaged DNA but are not involved in
replication.
dNTPs are byproducts of DNA replication that are discarded.
dNTPs are involved in protein synthesis and do not play a role in
DNA replication.
9. Describe the process by which freshwater fish maintain their ion balance
in a low-salt environment.
Freshwater fish take in water, excrete ions, and produce large
amounts of dilute urine.
Freshwater fish do not regulate water and ion balance.
Freshwater fish absorb ions from the water and produce
concentrated urine.
Freshwater fish excrete water and retain ions to maintain balance.
10. If a researcher wants to determine the presence of a specific gene in a
sample of genomic DNA, which technique should they use and why?
Gel electrophoresis, because it separates DNA fragments by
size.
Western blotting, because it detects proteins associated with
the gene.
Northern blotting, because it analyzes RNA expression levels.
, Southern blotting, because it allows for the detection of
specific DNA sequences using labeled probes.
11. What is the primary purpose of Gram staining in microbiology?
To assess the viability of bacterial cells.
To identify the presence of fungi in samples
To determine the size and shape of bacteria.
To distinguish between different types of bacterial cell walls.
12. Identify which of the following CORRECTLY describes the process of
neurulation.
the notochord arises from the dorsal endoderm
the posterior portion of the neural tube becomes the brain
the nervous system arises from the mesoderm
notochord induction causes folding of the ectoderm
13. What is the relationship between natural selection and evolution?
Natural selection is one process that can result in evolution.
They are the same thing.
The need for evolution causes natural selection to occur.
Natural selection changes a species in a short period of time,
whereas evolution takes much longer.
Natural selection only causes adaptations in allele frequencies,
whereas evolution can adapt an entire species.
14. Which statement best describes how bony fish osmoregulate?
They control the balance of ions gained across gills and
excreted in urine.
Verified Answers | Complete Dental Admission Test Prep
1. What type of bonds connect the base pairs in the DNA structure?
Covalent bonds
Peptide bonds
Hydrogen bonds
Ionic bonds
2. Describe how mutualism differs from parasitism in ecological
interactions.
Mutualism benefits both species involved, while parasitism
benefits one species at the expense of the other.
Mutualism involves competition between species, while
parasitism involves cooperation.
Mutualism occurs only in plants, while parasitism occurs in
animals.
Mutualism is harmful to both species, while parasitism is
beneficial to both.
3. Describe the initial stages of secondary succession and the types of
organisms that typically establish first.
Secondary succession involves the immediate return of all
original species.
Secondary succession starts with the growth of trees in a
completely barren area.
Secondary succession occurs only after a volcanic eruption.
Secondary succession begins with the establishment of shrubs
after a small disturbance.
,4. A bat wing and a human arm are said to be homologous structure. This
indicates that...
They have the same function
They are structures which are similar due to common ancestry
They have a different ancestry but a common function
The limb bones of each are anatomically identical
5. What is the definition of genetic drift?
A change in allele frequencies due to random sampling effects
A mechanism of evolution involving mutations
The movement of alleles between populations
A process of natural selection favoring certain traits
6. In a hypothetical population of birds where both very small and very
large beaks are favored due to food availability, what evolutionary
outcome might result from disruptive selection over several
generations?
Speciation
Extinction of the population
Increased competition
Stabilization of average beak size
7. If the notochord fails to develop properly during embryonic
development, what potential outcome could occur regarding the neural
tube?
Improper limb formation
Enhanced cognitive function
, Increased skin sensitivity
Neural tube defects
8. Describe the significance of dNTPs in the process of DNA replication.
dNTPs are essential for DNA replication as they provide the
necessary nucleotides for synthesizing new DNA strands.
dNTPs are used to repair damaged DNA but are not involved in
replication.
dNTPs are byproducts of DNA replication that are discarded.
dNTPs are involved in protein synthesis and do not play a role in
DNA replication.
9. Describe the process by which freshwater fish maintain their ion balance
in a low-salt environment.
Freshwater fish take in water, excrete ions, and produce large
amounts of dilute urine.
Freshwater fish do not regulate water and ion balance.
Freshwater fish absorb ions from the water and produce
concentrated urine.
Freshwater fish excrete water and retain ions to maintain balance.
10. If a researcher wants to determine the presence of a specific gene in a
sample of genomic DNA, which technique should they use and why?
Gel electrophoresis, because it separates DNA fragments by
size.
Western blotting, because it detects proteins associated with
the gene.
Northern blotting, because it analyzes RNA expression levels.
, Southern blotting, because it allows for the detection of
specific DNA sequences using labeled probes.
11. What is the primary purpose of Gram staining in microbiology?
To assess the viability of bacterial cells.
To identify the presence of fungi in samples
To determine the size and shape of bacteria.
To distinguish between different types of bacterial cell walls.
12. Identify which of the following CORRECTLY describes the process of
neurulation.
the notochord arises from the dorsal endoderm
the posterior portion of the neural tube becomes the brain
the nervous system arises from the mesoderm
notochord induction causes folding of the ectoderm
13. What is the relationship between natural selection and evolution?
Natural selection is one process that can result in evolution.
They are the same thing.
The need for evolution causes natural selection to occur.
Natural selection changes a species in a short period of time,
whereas evolution takes much longer.
Natural selection only causes adaptations in allele frequencies,
whereas evolution can adapt an entire species.
14. Which statement best describes how bony fish osmoregulate?
They control the balance of ions gained across gills and
excreted in urine.
