TEAS 7 Science Practice Test

Correct Answer: C

Rationale: The correct answer is C: controlled experiment. In a controlled experiment, the researcher manipulates one or more independent variables to observe the effect on the dependent variable, while controlling for other variables. In this scenario, the researcher is controlling the conditions and variables to study the impact of the manipulated independent variable on the dependent variable. Incorrect choices: A: Field experiment involves conducting research in real-world settings, which may not necessarily involve manipulation of variables. B: Natural experiment involves observing naturally occurring events without any manipulation by the researcher. D: Observational study involves observing and recording data without any intervention or manipulation of variables.

Correct Answer: A

Rationale: The correct answer is A. In a hypertonic solution, the concentration of solutes outside the cell is higher than inside. Water moves out of the cell via osmosis to equalize concentrations, causing the cell to shrink. This is due to the higher osmotic pressure outside the cell. Choices B and C are incorrect because in a hypertonic solution, water moves out of the cell, causing it to shrink, not swell or remain the same size. Choice D is incorrect as pH is not directly affected by osmosis.

Correct Answer: B

Rationale: In anaphase of mitosis, chromatids separate and move to opposite poles of the cell, ensuring each daughter cell receives a complete set of chromosomes. This ensures genetic stability and accurate distribution of genetic material. In metaphase, chromosomes align at the cell's equator but do not separate. Prophase is the initial stage of mitosis where chromosomes condense but do not divide, and telophase is the final stage where chromosomes decondense and nuclear envelopes reform. Therefore, anaphase is the correct phase where chromatids divide into chromosomes and migrate to opposite ends of the cell.

Correct Answer: A

Rationale: The correct answer is A: left atrium. During pulmonary circulation, oxygenated blood returns from the lungs to the heart. This oxygenated blood enters the heart through the pulmonary veins and specifically flows into the left atrium. The left atrium then contracts to push this oxygen-rich blood into the left ventricle, which pumps it out to the rest of the body. Summary: - B: right atrium receives deoxygenated blood from the body, not the lungs. - C: left ventricle receives blood from the left atrium, not directly from the lungs. - D: right ventricle pumps deoxygenated blood to the lungs, not receive blood from the lungs.

Correct Answer: C

Rationale: The correct answer is C, the law of independent assortment. This law states that alleles for different traits segregate independently of each other during gamete formation. This is due to the random alignment of homologous chromosomes during meiosis. The law of segregation (A) describes how alleles of a gene separate during gamete formation. The law of dominance (B) explains that one allele can mask the expression of another in heterozygous individuals. The law of predictive traits (D) is not a recognized Mendelian law and is therefore incorrect. In summary, the law of independent assortment best describes how alleles from different genes segregate independently during gamete formation.