TEAS 7 practice test science

Correct Answer: B

Rationale: The main organ responsible for regulating sleep is the hypothalamus. The hypothalamus plays a crucial role in controlling the body's circadian rhythm, which is the internal clock that regulates the sleep-wake cycle. It receives input from the eyes about light and darkness, aiding in determining when it's time to sleep or wake up. Additionally, the hypothalamus regulates the production of melatonin by the pineal gland, a hormone that helps control sleep patterns. While the thalamus relays sensory information to the brain, the pituitary gland is primarily responsible for hormone production and release, and the pineal gland produces melatonin under the control of the hypothalamus. Therefore, the hypothalamus is the correct choice as the main organ involved in sleep regulation.

Correct Answer: A

Rationale: An increase in surface area typically increases the force of friction between two surfaces. This is because with a larger surface area in contact, there are more points of contact between the surfaces, leading to a greater frictional force resisting motion. As a result, the correct answer is that an increase in surface area increases the force of friction between two surfaces. Choice B is incorrect because a greater surface area increases the frictional force. Choice C is incorrect because an increase in surface area results in more contact points and greater friction. Choice D is incorrect as the relationship between surface area and friction is predictable - an increase in surface area generally leads to an increase in frictional force.

Correct Answer: C

Rationale: The primary function of hair on the human body is protection. Hair acts as a barrier to protect the skin from external factors such as sunlight, dust, and other environmental elements. While hair can also provide some insulation by trapping heat near the body and contribute to sensory perception by detecting touch or movements, its main role is to safeguard the skin from potential harm, making protection the most essential function. Vitamin D synthesis is primarily related to the skin's exposure to sunlight and is not a direct function of hair.

Correct Answer: C

Rationale: The functional group present in amines is the amine group, represented as -NH2. Amines are organic compounds characterized by the presence of a nitrogen atom bonded to hydrogen atoms. The amine group distinguishes amines from other types of organic compounds, such as alcohols with the hydroxyl group, ketones with the carbonyl group, and nitro compounds with the nitro group. Therefore, the correct answer is 'C: Amine.'

Correct Answer: D

Rationale: The correct answer is the f orbital. Each f orbital can hold up to 2 electrons. Since there are 5 f orbitals, the total maximum number of electrons that can be accommodated in f orbitals is 10 (2 electrons per orbital x 5 orbitals = 10 electrons). Therefore, the f orbital can hold a maximum of 10 electrons. Choice A, s orbital, is incorrect because it can hold a maximum of 2 electrons. Choice B, p orbital, is incorrect because it can hold a maximum of 6 electrons (3 orbitals x 2 electrons per orbital = 6 electrons). Choice C, d orbital, is incorrect as it can hold a maximum of 10 electrons (5 orbitals x 2 electrons per orbital = 10 electrons), but the question asks for the type of orbital that can hold a maximum of 10 electrons, not the total number of electrons in d orbitals.