in the context of cholesterol levels ldl cholesterol is often referred to as

ATI TEAS 7

TEAS Test 7 science quizlet

1. In the context of cholesterol levels, LDL cholesterol is often referred to as:

A. HDL or "good" cholesterol.
B. LDL or "bad" cholesterol.
C. Total cholesterol, encompassing both LDL and HDL.
D. VLDL, a type of triglyceride transported in the bloodstream.

Correct answer: B

Rationale: LDL cholesterol is often referred to as "bad" cholesterol because high levels of LDL can lead to plaque buildup in the arteries, increasing the risk of heart disease and stroke. LDL cholesterol is considered harmful as it contributes to the formation of plaque in blood vessels, whereas HDL cholesterol helps remove LDL from the arteries. Choice A is incorrect because HDL is known as "good" cholesterol, which helps remove LDL cholesterol from the bloodstream. Choice C is incorrect as it refers to total cholesterol, which includes LDL, HDL, and other lipids. Choice D is incorrect as VLDL is a different type of lipoprotein that carries triglycerides and is not specifically related to LDL cholesterol.

2. How do killer T cells recognize infected cells?

A. The B cells flag the infected cells with amino acids.
B. Tiny bits of the virus's RNA are left around the cell.
C. Macrophages show up to help consume the infected cell.
D. The T cells have receptors that recognize the proteins the virus leaves on the surface of the cell.

Correct answer: D

Rationale: Killer T cells recognize infected cells by detecting viral proteins displayed on the surface of these cells. The T cells possess receptors specifically designed to identify these viral proteins, allowing them to target and eliminate the infected cells. Choice A is incorrect because B cells are not directly involved in the recognition process of infected cells by killer T cells. Choice B is incorrect because tiny bits of the virus's RNA being left around the cell is not how killer T cells primarily recognize infected cells. Choice C is incorrect because while macrophages play a role in immune responses, they do not directly assist in the recognition of infected cells by killer T cells.

3. What does the number of protons in the nucleus of an atom determine?

A. Mass number
B. Atomic number
C. Isotope
D. Valence electron count

Correct answer: B

Rationale: The number of protons in the nucleus of an atom is referred to as the atomic number. This atomic number is crucial as it uniquely identifies an element and determines its position on the periodic table. The mass number, on the other hand, represents the sum of protons and neutrons in an atom's nucleus. Isotopes are variants of elements with the same number of protons but differing numbers of neutrons. Valence electron count pertains to the number of electrons in the outermost energy level of an atom, which influences its chemical behavior.

4. Which of the following functions is NOT performed by the integumentary system, the skin?

A. Protect internal tissues from injury
B. Waterproof the body
C. Help regulate body temperature
D. Return fluid to the blood vessels

Correct answer: D

Rationale: The integumentary system, which includes the skin, performs various functions like protecting internal tissues from injury, waterproofing the body, and helping regulate body temperature. The function of returning fluid to the blood vessels is primarily associated with the lymphatic system, not the integumentary system. The skin contributes to fluid balance by regulating sweating and preventing excessive water loss, but it does not directly return fluid to the blood vessels, making this the correct answer. Choices A, B, and C are functions directly related to the integumentary system and are essential for maintaining the body's overall health and well-being.

5. Which hormone is released by the pituitary gland?

A. Estrogen
B. Luteinizing Hormone
C. Progesterone
D. Testosterone

Correct answer: B

Rationale: The correct answer is B: Luteinizing Hormone. The pituitary gland releases luteinizing hormone, which plays a crucial role in reproductive functions by stimulating ovulation in females and testosterone production in males. Choice A, Estrogen, is incorrect as estrogen is mainly produced by the ovaries. Choice C, Progesterone, is incorrect as progesterone is produced by the corpus luteum in the ovaries and the placenta during pregnancy. Choice D, Testosterone, is incorrect as testosterone is produced primarily in the testes in males and in smaller amounts in the ovaries and adrenal glands in females.