what are the differences between rna and dna

ATI TEAS 7

TEAS 7 science practice

1. What are the differences between RNA and DNA?

A. Both have the same structure and function.
B. RNA is single-stranded, while DNA is double-stranded.
C. RNA contains ribose sugar, while DNA contains deoxyribose sugar.
D. RNA has adenine and guanine, while DNA has thymine and cytosine.

Correct answer: B

Rationale: A) This statement is incorrect. RNA and DNA have different structures and functions. RNA is involved in protein synthesis and other cellular processes, while DNA stores genetic information. B) This statement is correct. RNA is typically single-stranded, while DNA is double-stranded, forming a double helix structure. C) This statement is correct. RNA contains ribose sugar in its backbone, while DNA contains deoxyribose sugar. D) This statement is incorrect. RNA contains adenine, guanine, cytosine, and uracil, while DNA contains adenine, guanine, cytosine, and thymine. Choice B is the correct answer as it accurately describes one of the key differences between RNA and DNA, emphasizing their structural disparity in terms of single-strandedness for RNA and double-strandedness for DNA. Choices A, C, and D contain inaccuracies regarding the structural and compositional distinctions between RNA and DNA, making them incorrect choices.

2. Which property of matter refers to the force of gravity acting on an object?

A. Mass
B. Weight
C. Density
D. Volume

Correct answer: B

Rationale: Weight is the property of matter that refers to the force of gravity acting on an object. Mass is the amount of matter in an object, not affected by gravity. Density is the mass per unit volume of a substance, not directly related to gravity. Volume is the amount of space that an object occupies, not a measure of gravity's force.

3. What is the primary function of the respiratory system?

A. to create sound and speech
B. to take oxygen into the body while removing carbon dioxide
C. to transport nutrients to the cells and tissue of the body
D. to act as a barrier between the body’s organs and outside influences

Correct answer: B

Rationale: The primary function of the respiratory system is to take oxygen into the body through inhalation and remove carbon dioxide through exhalation. Oxygen is essential for cellular respiration and energy production, while carbon dioxide is a waste product that needs to be expelled from the body. This process is vital for the functioning of the body's cells and tissues. Choices A, C, and D are incorrect because sound and speech production, nutrient transport, and acting as a barrier against outside influences are not the primary functions of the respiratory system. While the respiratory system is involved in speech production to some extent, its primary role is in gas exchange for respiration.

4. What type of reaction is represented by the following equation: 2C₆H₁₄ + 19O₂ → 12CO + 14H₂O?

A. Substitution reaction
B. Acid-base reaction
C. Enzyme reaction
D. Combustion reaction

Correct answer: D

Rationale: The given chemical equation represents a combustion reaction. Combustion reactions involve the burning of a hydrocarbon (C₆H₁₄) in the presence of oxygen (O₂) to produce carbon monoxide (CO) and water (H₂O). Combustion reactions typically release heat and light energy. In this case, the reactants are a hydrocarbon and oxygen, resulting in the formation of carbon monoxide and water. Choices A, B, and C are incorrect because the reaction does not involve substitution, acid-base reactions, or enzyme catalysis. Combustion reactions are characterized by the rapid combination of a substance with oxygen, leading to the production of heat and light energy.

5. What is the main factor limiting population growth in K-strategists?

A. Predation
B. Availability of resources
C. Competition
D. Disease

Correct answer: B

Rationale: K-strategists are species with a low reproductive rate that invest more resources in raising fewer offspring. These species typically live in stable environments with limited resources. The main factor limiting population growth in K-strategists is the availability of resources such as food, shelter, and space. When resources are scarce, K-strategists may struggle to find enough to support their population size, leading to reduced reproductive success and population growth. While predation, competition, and disease can also impact population growth, the primary limiting factor for K-strategists is the availability of resources.