TEAS Science Practice Test 2

Question 1

In human anatomy, an organ is best described as

A. a group of organelles that together perform a specific function.
B. a group of cells that together perform a specific function.
C. a group of tissues that together perform a specific function.
D. a group of membrane-enclosed structures that together perform a specific function.

Answer 1

C. a group of tissues that together perform a specific function. A group of tissues that functions together is an organ. For example, most organs contain connective tissue, vascular tissue, and more specific tissues such as hepatic tissues in the liver.

Question 2

Vaccines function through which of the following mechanisms?

A. Vaccine exposure increases production of macrophages.
B. Vaccine exposure creates dormant B cells for the secondary immune response.
C. Vaccine exposure forces an unusually strong primary immune response in the spleen.
D. Vaccine exposure creates multiple types of antigens.

Answer 2

B. Vaccine exposure creates dormant B cells for the secondary immune response. Vaccines consist of an inactive version of antigens from a pathogen such as a harmful bacterium or virus. The pathogen is recognized as a threat by the immune system, which moves to both destroy the pathogen and create memory cells, a type of B cell that is designed to attack a specific pathogen. Those cells lie dormant after the vaccine-induced infection has been destroyed, but if the body is exposed to that same pathogen again, the memory B cells can reproduce quickly and target that specific pathogen. This is the secondary immune response.

Question 3

After several minutes of strenuous activity, lactic acid can build up in skeletal muscle as a result of

A. aerobic respiration.
B. ATP breakdown.
C. lactate to pyruvate conversion.
D. fermentation.

Answer 3

D. fermentation. Lactic acid is a product of fermentation, the anaerobic process that occurs in muscles once oxygen has been exhausted during exertion.

Question 4

Within the pancreas, the structure(s) responsible for production of insulin is/are the

A. islets of Langerhans.
B. Kupfer cells.
C. interstitial fibroblasts.
D. uncinate process.

Answer 4

A. islets of Langerhans. The islets of Langerhans or pancreatic islands are located throughout the pancreas and contain the organ’s endocrine cells responsible for insulin production.

Question 5

What are the steps immediately before and after an action potential? Move the steps into the table, placing them in the correct order. Use all the steps.

Answer 5

The correct order is depolarization, threshold, repolarization, refractory period. Upon stimulation, positively charged sodium ions rush into the neuron (depolarization of the membrane). When a set membrane potential is reached, called the threshold, the action potential occurs. Sodium channels then close, blocking more sodium from entering the cell, and potassium channels open, allowing potassium ions to cross the membrane along their electrochemical gradient (repolarization). Then the cell enters a short period where the ionic concentrations and channel conditions return to resting state. During this time, called the refractory period, only an exceptionally strong stimulus will lead to a new action potential.

Question 6

When a person inhales, what is the final structure that oxygen enters before absorption into the bloodstream?

A. Trachea
B. Bronchiole
C. Capillary
D. Alveolus

Answer 6

D. Alveolus. The bronchioles dead end in tiny sacks called alveoli. Each alveolus is the site of gas exchange with the bloodstream and the effective endpoint of the airway.

Question 7

The long process of the incus connects the incus to

A. the malleus.
B. the stapes.
C. the mastoid process.
D. the styloid process.

Answer 7

C. the mastoid process. The mastoid process is part of the temporal bone of the skull, which surrounds the ear, but is not directly connected to the small bones within the ear.

Question 8

The chorion is best described as

A. the embryonic portion of the placenta.
B. the maternal portion of the placenta.
C. the interface between a fetus and the placenta.
D. the main source of gas exchange in the placenta.

Answer 8

A. the embryonic portion of the placenta. This is the correct answer. The placenta consists of both embryonic and maternal tissues. The embryonic tissues collectively are called the chorion.

Question 9

Triglycerides are a type of lipid best known for their

A. ability to catalyze reactions.
B. complex structure.
C. energy storage capability.
D. rigidity and strength.

Answer 9

C. energy storage capability. Triglycerides are the main component of stored fat. When broken down they provide more energy than carbohydrates.

Question 10

A cell expunges waste products through exocytosis. This is an example of

A. active transport.
B. diffusion.
C. channel-mediated transport.
D. passive transport.

Answer 10

A. active transport. Waste products are transported to the cell membrane in a vesicle, where they are expelled. The process requires energy and therefore is a type of active transport.

Question 11

In some flowers, red (F) demonstrates incomplete dominance over white (f). Incomplete dominant phenotype is pink. In an Ff × Ff cross, what percentage of offspring will be pink?

A. 0%
B. 25%
C. 50%
D. 100%

Answer 11

C. 50%. Under incomplete dominance, all heterozygote (Ff) offspring exhibit the incomplete dominant phenotype (pink, in this case). The Punnett square below indicates all the possible offspring of an Ff × Ff cross. Under independent assortment, half of the offspring should be genotype Ff, exhibiting the pink phenotype:

Graph

Question 12

Which substance can donate a proton or accept an electron pair during a chemical reaction?

A. H2O
B. HCl
C. NaCl
D. NH3

Answer 12

B. HCl. Substances that donate protons or receive electron pairs are acids, and HCl, or hydrochloric acid, meets these criteria.

Question 13

Which of the following organ systems plays a direct role in the removal of waste products?

A. Cardiovascular
B. Endocrine
C. Integumentary
D. Neuromuscular

Answer 13

C. Integumentary. While it is not the primary function of the integumentary system, this system does directly remove waste products through sweating.

Question 14

2H2O + energy are produced from which of the following reactions?

A. 2H2 + O2
B. 2H2 + O2 + energy
C. H2O2 + H2
D. H2O + H2O

Answer 14

B. 2H2 + O2 + energy. Hydrogen and water plus energy will combine in the highly exothermic water synthesis reaction.

Question 15

A person who lacks a gallbladder would experience difficulty with which of the following?

A. Digesting fat
B. Regulating blood sugar
C. Absorbing all nutrients
D. Swallowing

Answer 15

A. Digesting fat. The gallbladder stores bile produced by the liver, and bile is essential for the breakdown and absorption of lipids.

Question 16

Exchange between tissues and the cardiovascular circulation takes place in which structures?

A. Arteries
B. Arterioles
C. Capillaries
D. Venules

Answer 16

C. Capillaries. Capillaries are narrow blood vessels with extremely thin walls that connect arteries to tissues. Exchange between the blood and surrounding tissues occurs through the thin walls of the capillaries.

Question 17

Different variants of a particular trait, such as different eye colors, are the result of which of the following?

A. Alleles
B. Base pairing
C. Complementary strands
D. Homologous chromosomes

Answer 17

A. Alleles. Different versions of the same gene that code for different versions of the same trait are called alleles.

Question 18

Which of the following parts of the skeletal system also plays a direct role in digestion?

A. Atlas
B. Tongue
C. Hyoid
D. Tooth

Answer 18

A. Tooth. Teeth are part of the skeleton and perform the first steps of digestion by physically crushing food and breaking it into smaller pieces for swallowing and digestion.

Question 19

There are two containers of equal volume on a table. One container holds gas, and one holds liquid. The containers hold equal volumes of steam or liquid water, but this volume is less than the total volume of the container. Which statement describes the liquid water?

A. It is compressible.
B. It takes the shape of the entire container.
C. It takes the shape of the lower part of the container.
D. It has the lower density of the two substances.

Answer 19

C. It takes the shape of the lower part of the container. Since the volume of liquid water is lower than that of the container, the liquid will only fill the lower part of the container and take on the shape of the portion that it fills.

Question 20

Which of the following tools or procedures should a biologist use to amplify a trace amount of DNA?

A. Mass spectrometer
B. PCR
C. Restriction enzyme
D. Sequencer

Answer 20

B. PCR. PCR (polymerase chain reaction) is a procedure that can turn a small amount of DNA into a much larger amount for easier study.

Question 21

Two researchers are studying the interaction between shrimp and fish. They place ten fish in a tank with a new type of shrimp and ten fish in another tank without the shrimp. All other factors are all well controlled. At the end of the experiment, the fish in the tank with the shrimp had grown 30% more than the fish without shrimp. What additional step is needed to prove that the shrimp benefit the fish by removing parasites?

A. Count the parasites on every fish before and after the experiment.
B. Count the parasites on every fish before and after the experiment, and film the tanks during the experiment.
C. Reduce the food intake for the fish in the shrimp tank.
D. Repeat the experiment with more replicates.

Answer 21

B. Count the parasites on every fish before and after the experiment, and film the tanks during the experiment. If the shrimp are helping the fish by removing parasites, then it is necessary to prove that the faster-growing fish actually have fewer parasites and show through photographic evidence that the shrimp are responsible for their removal.

Question 22

Which of the following is a component of inflammation?

A. Antigen recognition
B. Constriction of blood vessels
C. Fibrin production
D. Increased permeability of blood vessels

Answer 22

D. Increased permeability of blood vessels. As part of an inflammatory response, the permeability of blood vessels increases, isolating damaged tissue from the general circulation. The leakage through the permeable vessels leads to swelling.

Question 23

Which of the following is the organelle in eukaryotic cells responsible for sorting and modifying proteins and lipids, folding polypeptides, and sorting and packaging molecules into vacuoles and vesicles?

A. Golgi apparatus
B. Endoplasmic reticulum
C. Lysosome
D. Centriole

Answer 23

A. Golgi apparatus. The Golgi complex is composed of flat disks called cisternae that are stacked in piles and surrounded by a complex network of tubules and vesicles. The Golgi complex is the packaging center for storage, distribution, and excretion. Many Golgi apparatuses are found in kidney cells. They are responsible for sorting and modifying proteins and lipids received from the rough endoplasmic reticulum (RER) and the smooth ER (SER) and for folding polypeptides to create proteins. These molecules are sorted and packaged into vacuoles and vesicles for storage, for transport to other parts of the cell, or for secretion.

Question 24

Researchers tested the time it took for hawks to find a real carcass and a realistic-looking model of a carcass. Both the carcass and the model were easily visible from above. Controlling for all other factors, they determined that hawks took about the same amount of time to find the model as they took to find the carcass. From this they concluded that hawks find their prey through their sense of smell. Which statement about their conclusion is most accurate?

A. The conclusion is correct since hawks easily found the dead carcass.
B. The conclusion should be that hawks use both scent and sight to find prey.
C. The conclusion is incorrect because the carcass is easily visible.
D. The conclusion would be correct if hawks took longer to find the model.

Answer 24

D. The conclusion would be correct if hawks took longer to find the model. The main difference between the treatments is that a carcass gives off an odor while a model does not, if they look the same. If hawks easily found the carcass but not the model, it would suggest that scent is more important that sight in locating prey.

Question 25

The diagram below illustrates feeding relationships, where each listed animal eats the species directly beneath it.
-diagram showing feeding relationships where foxes are on top of shrews are on top of grasshoppers are on top of plants-

Which of the following would be a likely result if the fox population increased dramatically?

A. The plant population would decrease.
B. The grasshopper population would decrease.
C. The shrew population would increase.
D. There would be no change.

Answer 25

A. The plant population would decrease. More foxes would eat more shrews, leaving fewer shrews to eat the grasshoppers. More grasshoppers would then eat more plants.

Question 26

Which of the following is the main function of the major calyces?

A. Drainage of urine into the ureter
B. Filtration of waste products from blood
C. Storage of excreted waste products
D. Active transport of salts out of blood

Answer 26

A. Drainage of urine into the ureter. After filtration, urine drains through several minor calyces into a major calyx. The major calices empty into the renal pelvis, which leads into the ureter.

Question 27

Aluminum (Al) has an atomic number of 13. How many valence electrons are in a neutral atom of aluminum?

A. 3
B. 8
C. 13
D. 26

Answer 27

A. 3. With an atomic number of 13, a neutral atom of aluminum has 13 total electrons. The first “shell” of electrons surrounding the nucleus of an atom holds 2 electrons, and all subsequent shells will hold up to 2(n2) electrons. With 2 electrons in the first shell and 8 in the second, that leaves 3 valence electrons in the outermost shell to add up to 13.

Question 28

Which of the following structures regulates the most endocrine system functions?

A. Coronary sinus
B. Hypothalamus
C. Thymus gland
D. Thyroid gland

Answer 28

B. Hypothalamus. The hypothalamus is the part of the brain that links nervous and endocrine function, controlling the release of hormones by endocrine glands.

Question 29

The heart is best described as a

A. dispenser.
B. meter.
C. pump.
D. pipe.

Answer 29

C. Pump. The heart serves exclusively to push blood throughout the body, much as a pump pushes water through a house’s plumbing.

Question 30

Which of the following is NOT true of viruses?

A. Viruses require living cells for survival and growth.
B. Viruses reproduce and mutate on their own.
C. Viruses can not be grown on a laboratory medium.
D. Viruses use the metabolic machinery of the host cell to synthesize viral enzymes and viral parts.

Answer 30

B. Viruses reproduce and mutate on their own. Viruses cannot reproduce or mutate on their own. It is living cells that reproduce and induce mutations in viruses.

Question 31

The following pairs of acids and bases are mixed together to produce an aqueous solution of a salt. Which pairing will produce the solution with the highest pH?

A. Weak acid, strong base
B. weak acid, weak base
C. strong acid, strong base
D. strong acid, weak base

Answer 31

A. Weak acid, strong base. Let’s analyze specific acids and bases to see what happens in these situations. The strong and weak base will be NaOH and NH3, respectively, and the strong and weak acid will be HCl and H3PO4, respectively. The salts made by the four combinations are shown below.

A) Weak acid, strong base: H3PO4 + NaOH → NaH2PO4 + H2O.

B) Weak acid, weak base: H3PO4 + NH3 → NH4H2PO4.

C) Strong acid, strong base: HCl + NaOH → NaCl + H2O.

D) Strong acid, weak base: HCl + NH3 → NH4Cl.

This choice will produce a solution with the highest pH because H2PO4– will react with water to produce OH– ions without producing H+ ions.

Question 32

Which type of microscope is used to view small objects on a glass slide?

A. Compound microscope
B. Confocal microscope
C. Dissecting microscope
D. Fluorescence microscope

Answer 32

A. Compound microscope. Compound microscopes are for very small samples that can be mounted on a slide and will allow light to penetrate.

Question 33

Urea is a waste compound that results from the breakdown of which of the following types of molecule?

A. Carbohydrate
B. Lipid
C. Sugar
D. Protein

Answer 33

D. Protein. Proteins break down into amino acids, which break down into ammonia. Liver enzymes convert ammonia into urea for removal from the blood by the kidneys.

Question 34

What is the first step in the scientific method?

A. Ask a question.
B. Conduct an experiment.
C. Do background research.
D. Formulate a hypothesis.

Answer 34

A. Ask a question. The first part of any scientific study is to decide what question the study will try to answer.

Question 35

Which of the following statements are true of solutions? Select all answers that apply.

A. All solutions are homogeneous mixtures.
B. All solutions involve a solid and a liquid.
C. A supersaturated solution is one that, under normal conditions, contains less solute than its maximal capacity.
D. The solvent dissolves the solute.

Answer 35

A. All solutions are homogeneous mixtures. D. The solvent dissolves the solute. Solutions are homogeneous mixtures by definition. A homogeneous mixture is uniform in appearance composition.

Question 36

In tropical forests, grass is more likely to burn than trees. Under drought conditions, grass grows back after a forest fire more easily than trees do. Which statement about forest health is true during drought conditions?

A. Droughts cause grass to grow.
B. Every fire makes additional fires more likely.
C. Fires cannot happen without grass.
D. Grass prevents the growth of trees.

Answer 36

B. Every fire makes additional fires more likely. If fire causes more grass to grow, and grass is more likely to burn, then each fire results in more grass and an ever-greater chance of further burning.

Question 37

DNA controls how all cellular forms of life will develop and grow because a strand of DNA will ultimately code for

A. the amino acids that comprise proteins.
B. the fatty acids and glycerol that comprise lipids.
C. the monosaccharides that comprise carbohydrates.
D. the nucleosides that comprise ATP.

Answer 37

A. the amino acids that comprise proteins. The nitrogenous base pairs form the genetic code stored in DNA. The sequence of the bases along a strand of DNA will ultimately code for the amino acid sequences that comprise a polypeptide chain or protein.

Question 38

What is the primary function of Merkel cells?

A. To hold keratinocytes together
B. To fight topical pathogens
C. To sense touch
D. To protect against radiation exposure

Answer 38

C. To sense touch. Merkel cells in the epidermis primarily sense light touch.