what does the term dilution refer to in a solution

ATI TEAS 7

TEAS Test 7 science

1. What does the term 'dilution' refer to in a solution?

A. Adding more solvent to decrease concentration
B. Adding more solute to increase concentration
C. Reducing the temperature to increase solubility
D. Increasing pressure to increase solubility

Correct answer: A

Rationale: The term 'dilution' in a solution refers to adding more solvent to decrease the concentration of the solution. Dilution involves reducing the concentration of the solute in the solution by increasing the amount of solvent. Choice B is incorrect because adding more solute would increase the concentration, not decrease it. Choices C and D are also incorrect as they relate to factors affecting solubility, not dilution specifically. Therefore, choice A is the correct answer as it accurately defines the process of dilution in a solution.

2. Which of the following is a cluster of capillaries that functions as the main filter of the blood entering the kidney?

A. The Bowman's capsule
B. The Loop of Henle
C. The glomerulus
D. The nephron

Correct answer: C

Rationale: The correct answer is C, the glomerulus. The glomerulus is a cluster of capillaries in the kidney responsible for filtering blood as it enters the nephron. It plays a crucial role in the initial stages of urine formation by filtering waste products and excess substances from the blood. Choice A, the Bowman's capsule, is incorrect as it surrounds the glomerulus and captures the filtrate. Choice B, the Loop of Henle, is incorrect as it is part of the nephron responsible for water reabsorption. Choice D, the nephron, is incorrect as it comprises the functional unit of the kidney and includes the glomerulus, Bowman's capsule, and other structures.

3. Which type of blood vessel carries blood away from the heart?

A. Vein
B. Artery
C. Capillary
D. Venule

Correct answer: B

Rationale: The correct answer is B: Artery. Arteries carry oxygen-rich blood away from the heart to various parts of the body. Veins, on the other hand, carry blood back to the heart. Capillaries are tiny blood vessels where oxygen and nutrients are exchanged with tissues. Venules are small veins that collect blood from capillaries, not from the heart, making them incorrect in this context.

4. Which of the following is NOT a recognized mode of natural selection?

A. Directional selection (favoring one extreme trait value on a spectrum)
B. Disruptive selection (favoring both extreme trait values on a spectrum)
C. Stabilizing selection (favoring the average trait value on a spectrum)
D. Sexual selection (selection based on mate choice that influences reproductive success)

Correct answer: D

Rationale: A) Directional selection is a recognized mode of natural selection where one extreme trait value on a spectrum is favored over others, leading to a shift in the average trait value over time. B) Disruptive selection is a recognized mode of natural selection where both extreme trait values on a spectrum are favored over the average trait value, potentially causing the population to split into distinct groups. C) Stabilizing selection is a recognized mode of natural selection favoring the average trait value on a spectrum over extreme values, resulting in reduced genetic diversity. D) Sexual selection differs from traditional natural selection modes as it involves mate choice and competition for mates, not direct selection pressure on traits affecting survival and reproduction in the environment. Sexual selection can drive the evolution of traits enhancing an individual's attractiveness for mating purposes.

5. What is the primary function of the pyloric sphincter?

A. to regulate the movement of food material from the stomach to the duodenum
B. to neutralize stomach acid
C. to prevent digested food materials and stomach acid from entering the esophagus
D. to begin the process of chemical digestion

Correct answer: A

Rationale: The primary function of the pyloric sphincter is to regulate the flow of partially digested food material (chyme) from the stomach into the small intestine, specifically the duodenum. This control is essential for proper digestion and absorption of nutrients in the small intestine. Choices B, C, and D are incorrect. Choice B is incorrect because neutralizing stomach acid is primarily the function of the stomach lining and antacid mechanisms. Choice C is incorrect because preventing the backflow of digested food materials and stomach acid into the esophagus is mainly the role of the lower esophageal sphincter. Choice D is incorrect because the chemical digestion process primarily starts in the stomach through the action of gastric juices, not the pyloric sphincter.