which statement confirms that the cell membrane is selectively permeable

ATI TEAS 7

ATI TEAS Practice Science Test

1. Which statement confirms that the cell membrane is selectively permeable?

A. Receptors are found on a cell's surface.
B. Cells communicate with each other using cell signals.
C. Environmental changes can cause a cell to expand or shrink.
D. Sodium ions must travel through ion channels to enter the cell.

Correct answer: D

Rationale: The correct answer is D because selective permeability is demonstrated by the fact that specific ions, such as sodium, require ion channels to cross the cell membrane. This process allows the cell to control what substances can enter or exit, highlighting the selective nature of the cell membrane. Choices A, B, and C do not directly relate to the concept of selective permeability of the cell membrane. Receptors on a cell's surface (Choice A) are involved in cell signaling rather than selective permeability. Cell communication through signals (Choice B) and environmental changes affecting cell size (Choice C) are not directly related to the selective permeability of the cell membrane, which specifically refers to the regulation of substances passing through the membrane.

2. Which type of cartilage allows for smooth movement at joints and absorbs shock?

A. Hyaline cartilage
B. Fibrocartilage
C. Elastic cartilage
D. None of the above

Correct answer: B

Rationale: Fibrocartilage is the correct answer. It is found in areas requiring both support and resilience, such as the intervertebral discs and knee joints. Fibrocartilage contains collagen fibers for strength and proteoglycans for resilience, making it suitable for functions that involve smooth movement at joints and shock absorption. Hyaline cartilage, while providing structural support, is not primarily responsible for smooth movement and shock absorption. Elastic cartilage is more flexible and is found in locations like the ear and epiglottis, but it is not known for its shock-absorbing properties. Choosing 'None of the above' disregards the correct option of fibrocartilage, which is specifically designed for the functions described in the question.

3. Which condition is commonly associated with frequent, painful urination?

A. Diabetes
B. Urinary tract infection (UTI)
C. Kidney stones
D. All of the above

Correct answer: D

Rationale: Frequent, painful urination can be indicative of various conditions. Diabetes may cause increased urination due to high blood sugar levels, UTIs can lead to pain and frequent urination, and kidney stones can also result in painful urination. Therefore, all of the options (A, B, and C) are correct in this scenario, making option D, 'All of the above,' the correct answer. Option D encompasses all the conditions commonly associated with frequent, painful urination, making it the most comprehensive and accurate choice.

4. When testing how quickly a rat dies based on the amount of poison it eats, which of the following is the independent variable and which is the dependent variable?

A. How quickly the rat dies is the independent variable; the amount of poison is the dependent variable.
B. The amount of poison is the independent variable; how quickly the rat dies is the dependent variable.
C. Whether the rat eats the poison is the independent variable; how quickly the rat dies is the dependent variable.
D. The cage the rat is kept in is the independent variable; the amount of poison is the dependent variable.

Correct answer: B

Rationale: The correct answer is B. In this experiment, the independent variable is the amount of poison because it is what is being manipulated by the researcher. The dependent variable is how quickly the rat dies, as it is the outcome that is being measured based on the different amounts of poison administered. Choice A is incorrect because the independent variable should be what is being manipulated or changed, which is the amount of poison in this case. Choice C is incorrect because whether the rat eats the poison is not being varied or controlled by the researcher. Choice D is incorrect because the cage the rat is kept in is not relevant to the relationship being studied between the amount of poison and the rat's survival time.

5. Define 'friction' in terms of opposing motion.

A. A force that increases motion
B. A force that accelerates motion
C. A force that opposes motion
D. A force that creates motion

Correct answer: C

Rationale: Friction is a force that opposes motion. When two surfaces are in contact, friction acts in the opposite direction to the motion or the potential motion between the two surfaces. It resists the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Friction hinders or prevents motion rather than promoting it. Choices A, B, and D are incorrect as they suggest that friction increases, accelerates, or creates motion, which is inaccurate. The correct definition of friction is that it opposes motion, making choice C the most appropriate option.