TEAS 7 practice test science

Correct Answer: B

Rationale: The aorta is the correct answer because it is the main artery in the body that carries oxygenated blood away from the heart to the rest of the body. The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. The superior and inferior vena cava are veins that carry deoxygenated blood from the body back to the heart. Therefore, choices A, C, and D are incorrect as they do not carry oxygenated blood away from the heart.

Correct Answer: B

Rationale: The correct answer is B: Hormones. The endocrine system communicates through hormones, which are chemical messengers produced by glands and released into the bloodstream to target specific cells or organs in the body. Enzymes are biological molecules that catalyze biochemical reactions, antibodies are part of the immune system, and neurons are cells that transmit nerve impulses. In this context, enzymes, antibodies, and neurons do not play roles in the endocrine system's communication process, making them incorrect choices.

Correct Answer: B

Rationale: Convergent evolution refers to the process by which different species independently evolve similar traits or characteristics due to similar environmental pressures. In the case of bats and birds, both have evolved wings for flight despite not sharing a recent common ancestor with wings. Bats are mammals, while birds are avians, yet they both have wings adapted for flight, which is a classic example of convergent evolution. A) Humans and chimpanzees share a common ancestor and have not independently evolved similar traits. C) Dolphins and sharks are not closely related, and their similarities are due to adaptations to their aquatic environment rather than convergent evolution. D) Snakes and earthworms belong to different classes (reptiles and annelids, respectively) and do not share recent common ancestors, making their similarities not a result of convergent evolution.

Correct Answer: C

Rationale: A) Mutations in genes can introduce new genetic variations into a population, which can be acted upon by natural selection. B) Differential survival and reproduction based on traits is a key component of natural selection, as individuals with advantageous traits are more likely to survive and pass on their genes to the next generation. C) Inheritance of acquired characteristics, also known as Lamarckism, is not a mechanism of evolution by natural selection. Traits acquired during an individual's lifetime (such as strong muscles from working out) are not passed on to offspring. D) Competition for resources in an environment can drive natural selection by favoring individuals with traits that help them better compete for limited resources. Therefore, the correct answer is C) Inheritance of acquired characteristics (like strong muscles from working out), as it is not a mechanism that can directly cause evolution by natural selection.

Correct Answer: D

Rationale: The correct answer is D, the cell wall. The cell wall is the structure in plant cells that provides rigidity and support. It is a tough, rigid structure located outside the cell membrane. Composed primarily of cellulose, the cell wall offers structural support to the cell, helping it maintain its shape and protect it from damage. The other choices, such as the cell membrane (choice A), Golgi apparatus (choice B), and plastid (choice C) do not provide rigidity and support to plant cells. The cell membrane is a selectively permeable barrier, the Golgi apparatus is involved in processing and packaging proteins, and plastids are organelles responsible for functions like photosynthesis and storage, but they do not provide the structural support that the cell wall does.