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 represents the correct order of airflow in the lungs?

A. Bronchi, trachea, alveoli, bronchioles
B. Alveoli, bronchioles, bronchi, trachea
C. Trachea, bronchi, bronchioles, alveoli
D. Bronchioles, alveoli, trachea, bronchi

Correct answer: C

Rationale: The correct order of airflow in the lungs starts with air entering through the trachea, moving into the bronchi, then proceeding to the bronchioles, and finally reaching the alveoli where gas exchange occurs. Therefore, the correct sequence is Trachea, Bronchi, Bronchioles, Alveoli, making choice C the accurate representation of the airflow in the lungs. Choices A, B, and D are incorrect because they do not follow the anatomical path of airflow in the lungs as air moves from the trachea to the bronchi, then bronchioles, and finally the alveoli for gas exchange.

3. Which muscles play a significant role in the process of forced exhalation by contracting to reduce the thoracic cavity volume?

A. Diaphragm
B. External intercostal muscles
C. Internal intercostal muscles
D. Abdominal muscles

Correct answer: D

Rationale: The abdominal muscles play a significant role in forced exhalation by contracting to reduce the thoracic cavity volume. When these muscles contract, the pressure within the thoracic cavity increases, assisting in the expulsion of air from the lungs. This action helps to compress the abdomen and push the diaphragm upwards, further decreasing the volume of the thoracic cavity and aiding in the exhalation process. The diaphragm (Choice A) is mainly involved in inhalation by contracting and moving downward to increase thoracic cavity volume. External intercostal muscles (Choice B) and internal intercostal muscles (Choice C) are primarily involved in the process of inhalation by expanding the thoracic cavity during normal breathing, rather than forced exhalation.

4. Which organ system is most responsible for maintaining control of body temperature?

A. The skeletal system.
B. The circulatory system.
C. The immune system.
D. The muscular system.

Correct answer: B

Rationale: The circulatory system is the correct answer as it plays a crucial role in maintaining control of body temperature through a process called thermoregulation. Blood vessels near the skin surface dilate to dissipate heat when the body is too warm and constrict to reduce heat loss when it's too cold. Additionally, the circulatory system helps distribute heat produced from metabolic processes throughout the body to keep a stable internal temperature. The skeletal system provides structural support, the immune system defends against pathogens, and the muscular system is responsible for movement, but they are not primarily involved in regulating body temperature.

5. What is the main difference between a telescope and a microscope?

A. Telescopes magnify distant objects, while microscopes magnify small objects.
B. Telescopes use lenses, while microscopes use mirrors.
C. Telescopes collect light, while microscopes emit light.
D. They both magnify objects but serve different purposes.

Correct answer: A

Rationale: The main difference between a telescope and a microscope lies in their primary functions. Telescopes are specifically designed to magnify and observe distant objects like stars, planets, and galaxies, making them essential tools for astronomy. In contrast, microscopes are utilized to magnify and study small objects such as cells, bacteria, and other microscopic organisms in fields like biology and medicine. Therefore, the key distinction is that telescopes focus on magnifying distant objects, while microscopes are tailored for magnifying small objects. Choice B is incorrect because while some microscopes may use mirrors in certain designs, the primary component is typically lenses. Choice C is incorrect as telescopes collect and focus light for observation, while microscopes use light to illuminate and magnify objects. Choice D is incorrect because while both instruments magnify objects, their main purposes and the types of objects they focus on are distinctly different.