TEAS 7 science study guide free

Correct Answer: B

Rationale: The correct answer is B, the menstrual cycle. The menstrual cycle is the monthly series of changes that occur in the female reproductive system, preparing the body for potential pregnancy. One of the key events in this cycle is the thickening of the uterine lining in anticipation of receiving a fertilized egg. If fertilization does not occur, this thickened lining is shed during menstruation. Choices A, C, and D are incorrect. The ovulation cycle specifically refers to the release of the egg from the ovary, not the entire monthly reproductive cycle. The implantation cycle is the phase when a fertilized egg attaches to the uterine lining, not the overall monthly cycle. The gestation cycle pertains to the period of development from conception to birth, not the cycle preparing for potential pregnancy.

Correct Answer: C

Rationale: A raised hammer represents potential energy as it possesses stored energy due to its position above the ground. When the hammer falls, this potential energy is converted into kinetic energy as it moves. In contrast, options A, B, and D involve objects already in motion, representing kinetic energy. Choice A, a moving car, is in motion and has kinetic energy. Choice B, a spinning top, is also in motion and exhibits kinetic energy. Choice D, a rolling ball, is already moving and thus has kinetic energy. Therefore, only choice C, a raised hammer, is the correct representation of potential energy among the given options.

Correct Answer: B

Rationale: In circular motion at a constant speed, the car has a constant centripetal acceleration (choice A), experiences a force directed towards the center of the circle (choice C), and covers the same distance in equal time intervals along its circular path (choice D). However, the tangential velocity of an object in circular motion at a constant speed changes continuously as it moves around the circle, so it is not constant (choice B). The change in tangential velocity allows the car to maintain its motion in a circular path despite moving at a constant speed. Choice A is incorrect because centripetal acceleration is indeed present to keep the car moving in a circular path. Choice C is incorrect as a force towards the center is required to keep the car in circular motion. Choice D is incorrect because the car covers equal distances in equal time intervals to maintain its circular trajectory.

Correct Answer: D

Rationale: Amino acids are linked together by covalent bonds to form proteins. Specifically, the bond that links amino acids together is called a peptide bond, which is a type of covalent bond. The peptide bond forms between the amino group of one amino acid and the carboxyl group of another amino acid, resulting in the formation of a peptide chain. While hydrogen bonds, ionic bonds, and disulfide bonds are important for protein structure and stability, the primary bond responsible for linking amino acids in a protein chain is the covalent peptide bond. Hydrogen bonds are involved in maintaining the secondary structure of proteins, such as alpha helices and beta sheets. Ionic bonds and disulfide bonds contribute to tertiary and quaternary structures of proteins by stabilizing interactions between different parts of the protein or between different protein subunits, respectively.

Correct Answer: B

Rationale: Vitamin C is essential for collagen production, a key component of connective tissues. Collagen, a crucial protein, provides structure and strength to various body tissues, such as skin, tendons, ligaments, and blood vessels. Vitamin C plays a pivotal role in collagen synthesis by aiding in the hydroxylation of proline and lysine residues, which is essential for stabilizing the collagen structure. A deficiency in vitamin C can lead to impaired collagen production, resulting in conditions like scurvy, characterized by weakened connective tissues. Vitamin A (Choice A) is important for vision and immune function but is not directly involved in collagen production. Vitamin D (Choice C) is essential for calcium absorption and bone health but is not primarily responsible for collagen synthesis. Vitamin E (Choice D) acts as an antioxidant, protecting cells from damage, but it is not a key player in collagen production.