which part of the brain controls breathing and heart rate

ATI TEAS 7

Practice TEAS Science Test

1. Which part of the brain controls breathing and heart rate?

A. Cerebrum
B. Medulla oblongata
C. Thalamus
D. Cerebellum

Correct answer: B

Rationale: The medulla oblongata is the correct answer because it is responsible for controlling involuntary functions such as breathing and heart rate. The cerebrum (Choice A) is primarily associated with higher brain functions like thinking and voluntary movements, not with regulating basic bodily functions like breathing and heart rate. The thalamus (Choice C) serves as a relay station for sensory information but is not directly involved in controlling breathing and heart rate. The cerebellum (Choice D) plays a role in coordination and balance, not in regulating respiratory and cardiac functions.

2. Which statement is true about the pH of a solution?

A. A solution cannot have a pH less than 0.
B. A solution always has a pH of 7.
C. A solution's pH is not influenced by its chemical composition.
D. A solution with a pH of 14 is considered acidic.

Correct answer: A

Rationale: The pH scale ranges from 0 to 14, with 0 being the most acidic, 7 neutral, and 14 the most basic. A solution with a pH less than 0 would be outside the defined pH range, as 0 is the lower limit. Therefore, a solution cannot have a pH less than 0. Choice B is incorrect because a pH of 7 is considered neutral, not always the pH of a solution. Choice C is incorrect because a solution's pH is influenced by its chemical composition. Choice D is incorrect as a solution with a pH of 14 is considered highly basic, not acidic.

3. When calcium chloride (CaCl2) dissolves in water, it separates into its ions (Ca2+ and Cl-). This is an example of:

A. Chemical change
B. Physical change
C. Precipitation
D. Neutralization

Correct answer: B

Rationale: When calcium chloride dissolves in water, it separates into its ions without forming a new substance, which is characteristic of a physical change. A physical change involves alterations in the substance's physical properties without changing its chemical composition. In this scenario, the chemical formula of calcium chloride remains unchanged, and only its physical state changes by creating ions in the solution. Therefore, the dissolution of calcium chloride in water is an example of a physical change. Choice A, 'Chemical change,' is incorrect because no new substances are formed during the dissolution process. Choice C, 'Precipitation,' is incorrect as precipitation involves the formation of an insoluble solid when two solutions react. Choice D, 'Neutralization,' is incorrect as it refers to a reaction between an acid and a base to form salt and water, which is not the case in the given scenario.

4. What is the correct way to represent 8,600,000,000,000 in scientific notation with two significant figures?

A. 8.6 x 10^12
B. 8.6 x 10^-12
C. 8.6 x 10^11
D. 8.60 x 10^12

Correct answer: A

Rationale: The correct way to represent 8,600,000,000,000 in scientific notation with two significant figures is 8.6 x 10^12. Scientific notation involves expressing a number as a decimal (with one non-zero digit before the decimal point) multiplied by a power of 10. In this case, 8,600,000,000,000 is correctly written as 8.6 x 10^12 to maintain two significant figures and the appropriate magnitude. Choice B (8.6 x 10^-12) is incorrect as it represents a very small number due to the negative exponent. Choice C (8.6 x 10^11) is incorrect as it does not account for the magnitude of the original number. Choice D (8.60 x 10^12) is incorrect because it unnecessarily adds a zero after the decimal point, which is not warranted by the original number's precision.

5. The liver plays a vital role in digestion. What is one of the main functions of the liver in the digestive system?

A. Physical breakdown of food
B. Production of digestive enzymes
C. Storage and processing of nutrients
D. Elimination of waste products

Correct answer: C

Rationale: The correct answer is C: Storage and processing of nutrients. The liver plays a crucial role in processing nutrients absorbed from the small intestine, storing glycogen, vitamins, and minerals, and regulating blood sugar levels by releasing or storing glucose as needed. Choices A, B, and D are incorrect because the physical breakdown of food primarily occurs in the mouth and stomach, the production of digestive enzymes is mainly carried out by the pancreas and small intestine, and the elimination of waste products is primarily managed by the large intestine and kidneys, not the liver.