which statement below correctly describes the movement of molecules in the body andor in relation to the external environment

ATI TEAS 7

ATI TEAS 7 Science Practice Test

1. Which statement below correctly describes the movement of molecules in the body and in relation to the external environment?

A. Osmosis is the movement of a solution from an area of low solute concentration to an area of high solute concentration.
B. Diffusion is the process in which oxygen moves from the lungs into the bloodstream.
C. Dissipation is the transport of molecules across a semipermeable membrane from low to high concentration.
D. Reverse osmosis is the movement of molecules in a solution from high concentration to low concentration.

Correct answer: B

Rationale: The correct answer is B. Diffusion is the process where molecules move from an area of higher concentration to an area of lower concentration. In the context of the lungs, oxygen moves from the alveoli in the lungs to the bloodstream through diffusion. Choice A is incorrect as osmosis involves the movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration. Choice C is incorrect because dissipation does not refer to a specific biological process related to molecule movement. Choice D is incorrect as reverse osmosis is a process where solvent moves from an area of high solute concentration to an area of low solute concentration, not the movement of molecules within a solution.

2. Which of the following is the main organ responsible for regulating blood pressure?

A. Heart
B. Kidneys
C. Adrenal glands
D. Pituitary gland

Correct answer: B

Rationale: The kidneys play a crucial role in regulating blood pressure through various mechanisms. One of the key ways the kidneys regulate blood pressure is by controlling the volume of blood in the body. They do this by adjusting the amount of water and sodium excreted in the urine. The renin-angiotensin-aldosterone system, primarily controlled by the kidneys, also plays a significant role in blood pressure regulation. This system helps to maintain blood pressure by regulating blood volume and systemic vascular resistance. While the heart, adrenal glands, and pituitary gland are involved in various aspects of the cardiovascular and endocrine systems, the kidneys are the main organ responsible for regulating blood pressure.

3. What is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division?

A. Centromere
B. Chromatid
C. Chromosome
D. Gene

Correct answer: C

Rationale: A chromosome is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly before cell division. It contains the genetic material and is essential for cell division and replication. The centromere is a specific region of a chromosome that plays a role in cell division. A chromatid is one half of a duplicated chromosome, and a gene is a unit of heredity responsible for specific traits. Therefore, the correct answer is 'Chromosome' as it represents the entire condensed DNA molecule during cell division.

4. Identify the INCORRECT function of the liver.

A. Bile production to aid digestion.
B. Synthesis of blood proteins, such as albumin.
C. Storage of glucose for energy regulation.
D. Filtration of waste products from the blood.

Correct answer: D

Rationale: A) Correct - The liver produces bile, which aids in the digestion and absorption of fats in the small intestine. B) Correct - The liver is responsible for synthesizing blood proteins, including albumin, which helps maintain osmotic pressure in the blood. C) Correct - The liver stores glucose in the form of glycogen and helps regulate blood sugar levels by releasing glucose when needed. D) Incorrect - The liver does not filter waste products from the blood. Instead, the kidneys are responsible for filtering waste products from the blood and excreting them in the form of urine.

5. Which element is essential for the formation of hemoglobin?

A. Calcium
B. Iron
C. Potassium
D. Sodium

Correct answer: B

Rationale: The correct answer is Iron. Iron is essential for the formation of hemoglobin, the protein in red blood cells that binds and transports oxygen throughout the body. Calcium (Choice A), Potassium (Choice C), and Sodium (Choice D) are not directly involved in the formation of hemoglobin and its oxygen-carrying function.