TEAS 7 science practice questions

Correct Answer: A

Rationale: Proteins are made up of long chains of amino acids, and there are 20 standard amino acids commonly found in proteins. The sequence and arrangement of these amino acids determine the structure and function of a protein. While proteins can vary in size and complexity, the number of amino acids typically ranges from around 10 to 20 in smaller proteins to hundreds or even thousands in larger proteins. Therefore, the range of 10-20 amino acids is the most accurate representation of the number of amino acids that can make up a protein. Choices B, C, and D are incorrect as they provide ranges that are beyond the typical number of amino acids found in proteins and may lead to confusion. The correct answer is A (10-20).

Correct Answer: B

Rationale: - Water (option A) is a polar solvent due to its uneven distribution of charge, with the oxygen atom being partially negative and the hydrogen atoms being partially positive. - Ethanol (option B) is a nonpolar solvent because it has a symmetrical molecular structure that does not result in significant charge separation. - Acetone (option C) is a polar solvent as it contains a carbonyl group that results in a partial negative charge on the oxygen atom. - Hydrochloric acid (option D) is a polar solvent due to the presence of the highly electronegative chlorine atom, which results in a partial negative charge.

Correct Answer: C

Rationale: The Doppler effect is the perceived change in frequency of a wave due to relative motion between the source of the wave and the observer. This phenomenon is commonly observed with sound waves, where the pitch of a sound appears higher as the source moves towards the observer and lower as the source moves away. Option A is incorrect as the Doppler effect primarily applies to sound waves, not light waves. Option B is incorrect because the Doppler effect is not about the change in wave speed due to medium density but rather a change in perceived frequency. Option D is incorrect as it describes wave bending due to different mediums, which is not the primary concept behind the Doppler effect. Therefore, option C accurately describes the Doppler effect and its application to the shift in frequency of sound waves perceived by an observer.

Correct Answer: B

Rationale: In this context, a clone (option B) is a group of organisms that are genetically identical because they are derived from a single ancestor. A population (option A) refers to a group of individuals of the same species living in the same area. Genotype (option C) refers to the genetic makeup of an individual organism. Species (option D) refers to a group of organisms that can interbreed and produce fertile offspring. Therefore, the most appropriate choice for the question is 'Clone,' as it specifically refers to organisms with the same genetic makeup.

Correct Answer: C

Rationale: The correct answer is the prostate gland (Choice C). The prostate gland, located near the bladder, is responsible for producing seminal fluid. This fluid, along with sperm from the testes, makes up semen. The bladder stores urine, the urethra is a tube that carries urine from the bladder out of the body, and the kidney filters waste from the blood to produce urine. The prostate gland's specific function is to secrete a milky, alkaline fluid that mixes with sperm during ejaculation to form semen. This fluid helps nourish and protect the sperm, aiding in their motility and viability. Therefore, the prostate gland plays a crucial role in male reproductive function by contributing to the composition and quality of semen, essential for fertility.