TEAS 7 Science Practice Test

Correct Answer: C

Rationale: The correct answer is C: hypodermis. The hypodermis is the deepest layer of the skin and acts as an energy reserve by storing adipocytes (fat cells) that can be used for energy when needed. Adipocytes in the hypodermis help to insulate the body and provide cushioning. The epidermis (A) is the outermost layer of the skin that provides protection. The dermis (B) is the middle layer that contains blood vessels, nerves, and hair follicles. The stratum basale (D) is the bottom layer of the epidermis where new skin cells are produced. Therefore, the hypodermis is the correct answer as it specifically functions as an energy reserve through storing adipocytes.

Correct Answer: A

Rationale: The correct answer is A because atomic radius generally increases from top to bottom within a group and decreases from left to right across a period on the periodic table. This trend is due to the increasing number of energy levels (shells) as you move down a group, leading to larger atomic radii. Moving from left to right across a period, atomic radius decreases due to increasing effective nuclear charge pulling the electrons closer to the nucleus. Choices B, C, and D are incorrect as they do not accurately describe the trend of atomic radius across the periodic table.

Correct Answer: C

Rationale: The correct answer is C: skin. Skin is the primary physical barrier that the body uses to prevent infection. It acts as a protective barrier, preventing pathogens from entering the body. The outer layer of the skin, known as the epidermis, is made up of tightly packed cells that are difficult for pathogens to penetrate. Additionally, skin produces oils and sweat that contain antimicrobial properties, further protecting against infections. Explanation for why other choices are incorrect: A: Mucus membranes play a role in preventing infections in certain areas like the respiratory and digestive tracts, but they are not the primary physical barrier used by the body. B: Stomach acid is a chemical barrier rather than a physical barrier against infections. D: Urine helps to flush out pathogens from the urinary tract but is not the primary physical barrier used by the body.

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: C

Rationale: The correct answer is C: Antibodies. Adaptive immunity involves the body's ability to recognize and remember specific pathogens, such as viruses or bacteria. Antibodies are proteins produced by the immune system in response to these specific pathogens, providing targeted defense. In contrast, choices A and B (inflammation and fever) are examples of innate immunity, which are non-specific responses to pathogens. Choice D, phagocytosis, is a component of both innate and adaptive immunity, involving the engulfment and destruction of pathogens by immune cells. However, antibodies represent a key feature of adaptive immunity by specifically targeting and neutralizing pathogens.