TEAS Science Practice Test #3 3 — Questions and Answers
Question 1: What is the primary function of the large intestine?
- To absorb most of the nutrients from digested food
- To secrete digestive enzymes to break down proteins
- To absorb water and electrolytes, forming solid waste (Correct answer)
- To produce bile for fat digestion
Correct answer: To absorb water and electrolytes, forming solid waste
The large intestine (colon) primarily absorbs water and electrolytes from indigestible food matter, transforming liquid waste into solid feces for elimination. Most nutrient absorption occurs in the small intestine.
Question 2: Which of the following describes a dominant allele?
- An allele that is only expressed when two copies are present
- An allele that is always expressed when present, even with only one copy (Correct answer)
- An allele found only on the X chromosome
- An allele that causes disease in the heterozygous state
Correct answer: An allele that is always expressed when present, even with only one copy
A dominant allele is one that is expressed in the phenotype whenever it is present — whether in one copy (heterozygous) or two copies (homozygous dominant). A recessive allele is only expressed when two copies are present.
Question 3: Which of the following correctly describes the role of enzymes?
- Enzymes are consumed during a reaction and must be replenished
- Enzymes increase the temperature required to start a reaction
- Enzymes are biological catalysts that speed up chemical reactions without being consumed (Correct answer)
- Enzymes convert chemical energy into electrical energy
Correct answer: Enzymes are biological catalysts that speed up chemical reactions without being consumed
Enzymes are proteins that act as biological catalysts — they lower the activation energy needed for a chemical reaction to occur and are not consumed in the process, so they can be used repeatedly.
Question 4: What is the function of the trachea?
- To exchange gases between the blood and air
- To produce mucus and trap pathogens
- To conduct air from the larynx to the bronchi (Correct answer)
- To regulate breathing rate and rhythm
Correct answer: To conduct air from the larynx to the bronchi
The trachea (windpipe) is a cartilaginous tube that conducts inhaled air from the larynx (voice box) downward to the bronchi, which then branch into the lungs. It is lined with cilia and mucus to help filter debris.
Question 5: Which of the following is an example of a chemical property?
- Density
- Melting point
- Color
- Flammability (Correct answer)
Correct answer: Flammability
A chemical property describes a substance's ability to undergo a chemical change or reaction. Flammability (tendency to burn) is a chemical property. Density, melting point, and color are physical properties that can be observed without changing the chemical composition.
Question 6: What is the role of the sinoatrial (SA) node in the heart?
- To pump blood from the ventricles into the arteries
- To prevent backflow of blood between chambers
- To initiate the electrical impulse that causes the heart to contract (Correct answer)
- To receive deoxygenated blood from the body
Correct answer: To initiate the electrical impulse that causes the heart to contract
The SA node, located in the right atrium, is the natural pacemaker of the heart. It generates the electrical impulse that spreads across the atria, causing them to contract, then travels to the AV node and through the ventricles.
TEAS Science Practice Test #3 3
What is the primary function of the large intestine?