DAT Biology Practice Test 2025: 40 Questions

Last Updated on October 16, 2025

Dental Admission Test DAT Biology Practice Test 2025: 40 Questions. The biology knowledge you need for the DAT encompasses a wide variety of topics, including cell and molecular biology, diversity of life, vertebrate anatomy and physiology, developmental biology, genetics and evolution, and ecology and behavior.

Mastering biology on the DAT means not only memorizing biology vocabulary and facts but also learning to integrate your knowledge, make connections, and otherwise approach the multiple-choice questions in the Biology subtest and the entire Survey of Natural Sciences section in the best way possible.

Biology content appears in the Survey of Natural Sciences section, which contains the Biology, General Chemistry, and Organic Chemistry subtests. The Survey of Natural Sciences has a total of 100 questions that must be completed in 90 minutes. Questions 1–40 are always related to biology, questions 41–70 are always associated with general chemistry, and questions 71–100 are always related to organic chemistry.

DAT Biology Practice Test: 40 Questions

Dental Admission Test (DAT) Biology (1-40)

Dental Admission Test (DAT)
Topic: Biology
Total Questions: 40
Time Limit: 26.6 Minutes

1) Each of the following changes the frequency of alleles in a population EXCEPT one. Which one is the EXCEPTION?

Mutation

Natural selection

Immigration

Random interbreeding

Genetic drift

2) Each of the following cell organelles have a membranous structure EXCEPT one. Which one is the EXCEPTION?

Golgi complex

Centrioles

Mitochondria

Lysosomes

Endoplasmic reticulum

3) Sexual and asexual reproduction usually differ in

the ability of the new offspring to reproduce.

the rate at which mutations occur.

the amount of genotypic variation between parent and offspring.

the viability of offspring.

whether or not natural selection can occur.

4) What cellular organelles would you expect to be absent from fungi?

Mitochondria

Lysosomes

Ribosomes

Golgi bodies

Chloroplasts

5) In human beings, color blindness is controlled by an X-linked recessive allele. In a cross involving this X-linked trait, the male parent has normal color vision, but the female parent is a carrier. What are the chances (in %) that a male offspring will inherit color blindness?

100

6) In respiration, oxygen

combines with lactic acid to form pyruvic acid.

acts as a cofactor for glycolytic enzymes.

yields energy in the form of ATP as it is passed down the respiratory chain.

acts as an acceptor for electrons (and protons), forming water.

combines directly with carbon, forming CO2.

7) In anaerobic glycolysis in muscle cells, one mole of glucose is oxidized to

six moles of carbon dioxide.

two moles of acetic aid.

two moles of lactic acid.

two moles of acetyl CoA.

two moles of carbon dioxide and six moles of water.

8) Clotting of human blood

requires that hemoglobin be present.

results from fibrin joining globulin.

is a result of platelets releasing fibrinogen.

depends on the formation of fibrin from fibrinogen.

is accelerated when Ca2+ is removed.

9) Intracellular organelles that participate in metabolic oxidations involving H₂O₂ are called

centrioles

endoplasmic granules

peroxisomes

lysosomes

macrobodies

10) The human heart beat is initiated within the

sinus venosus.

Hensen’s node.

conus arteriosus.

artio-ventricular node.

sino-atrial node.

11) Of the following, which group of invertebrates is apparently most closely related to primitive vertebrates?

Annelida

Mollusca

Cnidaria

Arthropoda

Echinodermata

12) Organisms that obtain their energy from light can be termed

autotrophic

holotrophic

chemotrophic

heterotrophic

heliotrophic.

13) The two daughter cells formed by mitosis and cytokinesis have

half the number of chromosomes present in the parent cell.

half the number of the chromosomes present in the parent cell if this parent cell is found in the testicular or ovarian tissue.

the same number of chromosomes present in the parent cell.

twice the number of chromosomes present in the parent cell.

a variable number of chromosomes so that an exact prediction cannot be made

14) Which statement is true of the archenteron?

The cavity of the archenteron is called the blastocoele.

The cavity of the archenteron represents the beginning of the primitive gut.

The archenteron is formed during blastula formation.

The cavity of the archenteron represents the first cavity of the developing heart.

The archenteron is formed by a closing of the neural tube.

15) In watermelons, the unlinked genes for green color (G) and for short length (S) are dominant over alleles for striped color (g) and long length (s). Predict the phenotypes and their ratios for the cross Ggss x ggSs.

All green short

1:2:1 green short: striped long: striped short

All striped long

1:1:1:1 green short: striped short: green long: striped long

1:1 green short: striped long

16) Which statement concerning alleles is true for diploid organisms?

At most only two alleles occur at a given locus in an organisms genome.
Alleles occupy an identical locus in homologous chromosomes.
Alleles of a given gene usually occur on non-homologous chromosomes.
A single chromosome usually carries two alleles of each gene

1 and 2

1, 2 and 4

3 and 4

17) At some stage of development, all chordates have

a pharynx, a vertebral column, and a notochord.

pharyngeal pouches, a notochord, and a dorsal tubular nerve cord.

pharyngeal pouches, a notochord, and a ventral nerve cord.

pharyngeal pouches, vertebral column, and a dorsal tubular nerve cord.

a pharynx and an ectodermally derived, solid nerve cord

18) Fermentation

produces pyruvic acid as an end product.

yields less energy per mole of glucose than aerobic respiration

occurs only in the presence of oxygen

prevents glycolysis from occurring.

converts ethanol to glucose

19) The term motor unit refers to

an entire muscle.

a single muscle fiber.

all the muscle fibers innervated by one nerve fiber

all the motor nerves in one muscle.

all the sliding filaments of actin and myosin in one muscle fiber

20) Which is the smallest organelle in the cell?

Golgi body

Nucleus

Mitochondrion

Ribosome

Chloroplast

21) The initial step in the speciation process often involves

inbreeding within the species.

geographical separation of populations.

intraspecific-random mating.

the inheritance of acquired characteristics

a Hardy-Weinberg equilibrium.

22) Consider a pair of homologous human chromosomes. In this pair one would expect

them to be genetically identical.

one chromosome to carry dominant alleles and the other recessive alleles.

one chromosome to have been inherited from the mother and the other from the father.

the two chromosomes to synapse during mitotic prophase.

them to have different shapes.

23) A segment of DNA with the sequence GGCATTAGG would be transcribed into a messenger RNA segment with the sequence

CCGUAAUCC.

AATGCCGTT.

CCGTAATCC.

AAUGCCGUU.

CCGTUUTGG.

24) An enzyme is added to an aqueous solution of ATP, DNA, albumen, fat and glycogen; the reaction mixture is incubated for 10 minutes. If an analysis of the mixture reveals the presence of all of the above compounds plus glucose, it can be concluded that the enzyme hydrolyzed some of the

albumen

fat

glycogen

ATP

DNA

25) Embryonic induction is a process in which

embryonic tissues influence adjacent tissues to differentiate.

an unfertilized egg is induced to develop.

genes are transferred from one developing tissue to another.

resting potentials are induced in neurons of embryos.

the maternal parent induces expression of recessive genes in embryos.

26) For a given diameter of an axon, one factor which increases the velocity of a nerve impulse is

the length of the axon.

the ploidy of the nucleus.

the density of mitochondria along the axon

maximal stimulation of the neuron.

the presence of a myelin sheath.

27) As far as their products are concerned, all biosynthetic reactions in living cells result in

a more ordered state, therefore a decrease in entropy.

a more ordered state, therefore an increase in entropy.

energy released in the form of ATP.

energy made available for motion.

a more ordered state with no entropy change.

28) A complex behavioral response to a specific cue or releaser, which is exhibited by all members of the species as a stereotyped response to the same stimulus, is known as a

conditioned response.

fixed-action pattern.

reflex

kinesis

taxis

29) The movement of water soluble molecules through cell membranes, from higher to lower concentrations, by attachment to a carrier protein, describes

diffusions

osmosis

pinocytosis

active transport.

facilitated diffusion.

30) Of the germ layers comprising the early human embryo, which one forms most of the central nervous system?

Ectoderm

Mesoderm

Endoderm

Notochord

Dermis

31) Assuming no linkage, how many different kinds of gametes can be produced by an organism with the genotype AaBbcc?

32) Under the five-kingdom classification, members of the kingdom Monera are generally separated from the members of all the other kingdoms by having

heterotrophic nutrition versus autotrophic nutrition

unicellular organization versus multicellular organization

microscopic size versus macroscopic size

prokaryotic cells versus eukaryotic cells

parasite-host relationship versus predator-prey relationship

33) The addition of potassium iodide as a nutritional supplement to common table salt would most directly affect the function of which of these glands?

Thyroid

Sweat glands

Adrenal cortex

Kidneys

Parathyroid

34) Starch, cellulose and glycogen are all

proteins

linked internally by hydrogen bonds

water soluble

polymers of glucose

nucleic acids

35) Which chiefly stimulates action of the respiratory center?

Carbon dioxide in the blood

Relaxin

Lack of oxygen in the blood

Inflation of the alveolus

Vagus nerve

36) Organisms that have the characteristics of radial symmetry, water vascular system, a spiny skin, and are found exclusively in a marine habitat would be in which phylum?

Annelida

Chordata

Cnidaria

Porifera

Echinodermata

37) The long-term natural process by which a pond eventually becomes a terrestrial community is referred to as

environmental disruption.

habitat development.

organic evolution.

ecological succession.

desertification

38) Of the following, the rate and type of cleavage occurring after fertilization would be most affected by the

amount and distribution of yolk.

number of chromosomes.

thickness of the cell membrane.

temperature

thickness of the zona pellucida.

39) In the nephron of the kidney, filtration occurs between

Bowman’s capsule and Henle’s loop.

the glomerulus and Bowman’s capsule.

the proximal tubule and Henle’s loop.

Henle’s loop and the vasa recta.

the peritubular network and the convoluted tubules

40) Each of the following is synthesized by the anterior lobe of the pituitary gland of vertebrates EXCEPT one. Which one is the EXCEPTION?

Thyrotropic hormone

Adrenocorticotropic hormone

Follicle-stimulating hormone

Growth hormone

Oxytocin

Your score is

See also:

FREE DAT Practice Test 2025 Official Study Guide [PDF]