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 of the following is the best unit to measure the amount of blood in the human body?

A. Ounces
B. Liters
C. Milliliters
D. Pounds

Correct answer: B

Rationale: Liters are the best unit to measure the amount of blood in the human body because blood volume is typically measured in liters in the medical field. Using liters provides a standardized and accurate measurement of the significant amount of blood in the human body, which is typically around 5-6 liters for an average-sized adult. Other units like ounces, milliliters, and pounds are not commonly used to measure blood volume in clinical settings. Ounces are too small a unit for measuring blood volume, milliliters are less commonly used in this context compared to liters, and pounds are a unit of weight rather than volume.

3. What properties distinguish laser light from typical light sources?

A. Enhanced brightness only
B. Monochromatic nature (single color) and coherence (synchronized waves)
C. Increased velocity
D. Limited visibility to the human eye

Correct answer: B

Rationale: Laser light differs from typical light sources due to its monochromatic nature (single color) and coherence (synchronized waves). This means that laser light consists of a single wavelength and synchronized waves, unlike typical light sources that emit a range of wavelengths and are incoherent. The monochromatic nature of laser light allows it to be of a single color, while coherence ensures that the waves are synchronized. These unique properties of laser light make it valuable for a wide range of applications in fields such as medicine, industry, and research. Choices A, C, and D are incorrect because laser light's distinguishing features are not related to enhanced brightness, increased velocity, or limited visibility to the human eye. Instead, it is the monochromatic nature and coherence that set laser light apart from typical light sources.

4. Which respiratory structure is responsible for the humidification and warming of inhaled air?

A. Trachea
B. Larynx
C. Nasal passages
D. Bronchi

Correct answer: C

Rationale: The nasal passages are responsible for humidifying and warming inhaled air before it reaches the lungs. The mucous membranes in the nasal passages help add moisture to the air and warm it to body temperature. This process is crucial for protecting the lung tissues from potential damage caused by cold and dry air, ensuring optimal conditions for respiration. The trachea (Choice A) is responsible for conducting air to and from the lungs, the larynx (Choice B) is involved in sound production and protecting the airway during swallowing, and the bronchi (Choice D) are the branches of the trachea that further divide to deliver air to the lungs but are not primarily responsible for humidifying and warming inhaled air.

5. Which property of matter remains constant regardless of changes in gravity?

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

Correct answer: A

Rationale: Mass is a measure of the amount of matter in an object and remains constant regardless of changes in gravity. This is because mass is an intrinsic property of an object and does not depend on the gravitational field it is in. Weight, on the other hand, is the force of gravity acting on an object's mass and can vary depending on the strength of gravity. Volume is the amount of space an object occupies, which can change depending on the environment. Density is the mass of an object per unit volume, which can also change with variations in gravity. Therefore, the correct answer is Mass as it remains the same regardless of gravitational changes.