sweat glands help regulate body temperature by

ATI TEAS 7

ATI TEAS 7 science review

1. How do sweat glands help regulate body temperature?

A. Producing sebum for lubrication
B. Constricting blood vessels in the skin
C. Releasing a watery fluid that evaporates for cooling
D. Thickening the epidermis for insulation

Correct answer: C

Rationale: Sweat glands play a vital role in regulating body temperature by releasing a watery fluid that evaporates from the skin's surface. This evaporation process helps cool the body down by dissipating heat, which is essential for maintaining a stable internal temperature. Choice A is incorrect because sweat glands do not produce sebum but rather a watery fluid. Choice B is incorrect because sweating itself does not involve the constriction of blood vessels; instead, it promotes heat loss through evaporation. Choice D is incorrect as sweat glands do not thicken the epidermis for insulation but rather facilitate the cooling process through sweat evaporation.

2. Which of the following equations represents a redox reaction?

A. 2H2 + O2 → 2H2O
B. Zn + 2HCl → ZnCl2 + H2
C. 2NaCl → 2Na + Cl2
D. CH4 + 2O2 → CO2 + 2H2O

Correct answer: B

Rationale: A redox reaction involves the transfer of electrons between reactants. In option B, Zn loses electrons to form Zn2+ while H+ gains electrons to form H2. This exchange of electrons demonstrates a redox reaction, making choice B the correct answer. In options A, C, and D, there is no clear transfer of electrons between the reactants, indicating that they are not redox reactions. Option A represents a synthesis reaction, option C represents a decomposition reaction, and option D represents a combustion reaction. These types of reactions do not involve the transfer of electrons between reactants, unlike a redox reaction.

3. What is a gene, and what is the relationship between genes, genotype, and phenotype?

A. A gene is a sequence of amino acids; genes make up proteins; genotype determines phenotype
B. A gene is a portion of DNA; genes determine traits; genotype is the genetic makeup; phenotype is the physical manifestation
C. A gene is a protein; proteins determine traits; genotype is the set of all genes
D. A gene is a lipid; lipids determine traits; phenotype is the physical manifestation

Correct answer: B

Rationale: A gene is a portion of DNA that contains the instructions for a specific trait. Genotype refers to the genetic makeup of an organism, encompassing all its genes. Phenotype, on the other hand, is the observable physical manifestation resulting from the interaction between an organism's genotype and environmental factors. Choice A is incorrect because genes do not consist of amino acids directly; they are sequences of nucleotides. Choice C is incorrect as genes do not determine traits directly but provide the instructions for proteins that may influence traits. Choice D is incorrect as genes are not lipids, and lipids do not determine traits; they are a type of biomolecule with different functions.

4. What is insulin, where is it produced, and what is its function?

A. Produced in the liver, regulates fat storage
B. Produced in the pancreas, regulates blood sugar
C. Produced in the stomach, aids in digestion
D. Produced in the kidneys, controls hydration

Correct answer: B

Rationale: Insulin is a hormone produced in the pancreas. Its primary function is to regulate blood sugar levels by facilitating the uptake of glucose by cells for energy. The other choices are incorrect as insulin is not produced in the liver (Choice A), stomach (Choice C), or kidneys (Choice D), and its function is not related to fat storage, digestion, or hydration. Therefore, the correct answer is B.

5. Which of the following is an example of a salt?

A. Sodium hydroxide (NaOH)
B. Hydrochloric acid (HCl)
C. Sodium chloride (NaCl)
D. Sulfuric acid (H₂SO₄)

Correct answer: C

Rationale: Sodium chloride (NaCl) is an example of a salt. Salts are ionic compounds formed by the reaction of an acid with a base. In this case, sodium chloride is formed by the reaction of sodium hydroxide (a base) with hydrochloric acid (an acid). Sodium hydroxide (NaOH), hydrochloric acid (HCl), and sulfuric acid (H₂SO₄) are not salts because they are not formed by the neutralization reaction of an acid and a base, which is a characteristic of salts.