TEAS 7 Science Practice Test

Correct Answer: C

Rationale: The correct answer is C (50 neutrons). Neutrons are calculated by subtracting the atomic number from the mass number. The mass number represents the total number of protons and neutrons in an atom. Since the atomic number (number of protons) is not given, we use the mass number as a total. Therefore, for an atom with a mass number of 50, it must have 50 neutrons. Choice A (38) is incorrect because it does not match the given mass number. Choice B (88) is incorrect as it is not the correct calculation based on the mass number provided. Choice D (126) is incorrect as it is not the correct calculation based on the mass number provided.

Correct Answer: C

Rationale: The correct answer is C (50 neutrons). Neutrons are calculated by subtracting the atomic number from the mass number. The mass number represents the total number of protons and neutrons in an atom. Since the atomic number (number of protons) is not given, we use the mass number as a total. Therefore, for an atom with a mass number of 50, it must have 50 neutrons. Choice A (38) is incorrect because it does not match the given mass number. Choice B (88) is incorrect as it is not the correct calculation based on the mass number provided. Choice D (126) is incorrect as it is not the correct calculation based on the mass number provided.

Correct Answer: D

Rationale: The correct answer is D: insulin production and blood sugar regulation. The liver is not responsible for insulin production; it is produced by the pancreas. The liver does play a role in blood sugar regulation by storing and releasing glucose, but it is not the primary organ for insulin production. The other choices (A, B, C) are functions of the liver: A) nutrient processing involves metabolizing and storing nutrients, B) blood filtration and detoxification involves removing toxins from the blood, and C) cholesterol and lipoprotein production involves synthesizing cholesterol and lipoproteins.

Correct Answer: B

Rationale: The correct answer is B: A dominant allele will always be expressed. This is because dominant alleles mask the expression of recessive alleles in heterozygous individuals. This means that if an individual carries at least one dominant allele for a particular trait, that dominant allele will be expressed phenotypically. In contrast, recessive alleles are only expressed when an individual is homozygous for that allele. Now, let's analyze the other choices: A: All genes adhere to Mendel's law of dominance - This is incorrect as not all genes follow Mendel's law of dominance, especially in cases of incomplete dominance or codominance. C: When two dominant alleles are present, the resulting phenotype will express both traits - This is incorrect as dominance determines which allele is expressed, so only the dominant trait will be expressed in this case. D: There are three or more alleles possible for all genes - This is incorrect as some genes may have multiple alleles, but not all genes have three

Correct Answer: D

Rationale: The correct answer is D because a control group is necessary in experiments to compare results with a group that does not receive the experimental treatment. In this case, if tanks A, B, or C were chosen as the control group, there would be no basis for comparison with a group that did not receive any treatment. Therefore, without a specific control group that does not undergo any experimental manipulation, it is not possible to determine the true impact of the treatment being tested. Tanks A, B, and C cannot serve as the control group in this experiment as they are all part of the experimental setup and are not kept untreated for comparison.