Science TEAS Practice Test

Correct Answer: C

Rationale: The correct answer is C: The rectum. The genitourinary system consists of organs involved in reproduction and waste elimination. The rectum is part of the digestive system, not the genitourinary system. The kidneys (A), urethra (B), and bladder (D) are all essential components directly involved in the production, storage, and elimination of urine. The rectum plays a role in the elimination of solid waste and is not part of the genitourinary system.

Correct Answer: B

Rationale: The correct answer is B: Secondary structure. Secondary structure refers to the local folding patterns of the polypeptide backbone, mainly involving alpha helices and beta sheets. This level of protein structure is determined by hydrogen bonding between amino acids along the backbone. Primary structure (A) is the linear sequence of amino acids, tertiary structure (C) refers to the overall 3D shape of a protein, and quaternary structure (D) involves the arrangement of multiple protein subunits. In this case, the question specifically asks about the folds and coils of the polypeptide backbone, which align with the characteristics of secondary structure.

Correct Answer: D

Rationale: The correct answer is D: Homeostasis. The endocrine system is responsible for regulating various physiological processes to maintain internal balance, or homeostasis, within the body. Hormones released by endocrine glands help control metabolism, growth, reproduction, and other functions. Choice A (Heartbeat) is controlled by the cardiovascular system, not the endocrine system. Choice B (Respiration) is controlled by the respiratory system. Choice C (Electrolyte and water balance) is regulated by the kidneys and not directly by the endocrine system. Thus, the primary function of the endocrine system is to maintain homeostasis through hormone regulation.

Correct Answer: B

Rationale: The correct answer is B: A gene. A gene is the smallest unit that can encode for a trait because it is a specific sequence of nucleotides in the DNA that provides instructions for a particular trait or function. Genes determine our physical characteristics and traits. A codon (choice A) is a sequence of three nucleotides that code for a specific amino acid in protein synthesis, not a complete trait. A nucleotide (choice C) is the basic building block of DNA, but it is not capable of encoding for a trait on its own. A chromosome (choice D) is made up of DNA and contains multiple genes, so it is not the smallest unit that can encode for a trait.

Correct Answer: D

Rationale: The correct answer is D: Ionic bond. In an ionic bond, electrons are transferred from one atom to another, resulting in the formation of positively and negatively charged ions that are attracted to each other. This transfer of electrons leads to the creation of a strong bond between the atoms. A: Transfer bond is not a recognized term in chemistry. B: Static bond is not a valid type of bond in chemistry. C: Covalent bond involves the sharing of electrons between atoms, not the transfer of electrons like in an ionic bond.