what is a mutation

ATI TEAS 7

TEAS 7 science practice questions

1. What is a mutation?

A. A change in the DNA sequence
B. A type of protein
C. A normal part of the DNA replication process
D. A harmless variation in DNA

Correct answer: A

Rationale: A mutation is defined as a change in the DNA sequence, which can occur due to various factors such as errors during DNA replication, exposure to mutagens (e.g., chemicals, radiation), or spontaneous changes. These alterations can lead to modifications in the genetic information carried by an organism, resulting in effects that can range from harmless variations to causing genetic disorders or diseases. Mutations play a crucial role in genetic diversity and evolution. Choices B, C, and D are incorrect as they do not accurately define what a mutation is. Option B is incorrect because mutations are not a type of protein but rather changes in DNA. Option C is incorrect because while mutations can occur during DNA replication, they are not considered a 'normal' part of the process as they can lead to genetic variations. Option D is incorrect because mutations can have a wide range of effects and are not always harmless variations.

2. Where is the major site for nutrient absorption in the digestive system?

A. Mouth
B. Stomach
C. Small intestine
D. Large intestine

Correct answer: C

Rationale: The small intestine is recognized as the major site for nutrient absorption in the digestive system. It plays a crucial role in the digestion and absorption of nutrients from food. The small intestine's villi and microvilli provide a large surface area specialized for absorbing nutrients like carbohydrates, proteins, fats, vitamins, and minerals. This efficient absorption process is essential for supplying the body with the necessary nutrients for energy production, growth, and overall functioning. The mouth is primarily involved in the initial stages of digestion through mechanical and chemical breakdown of food. The stomach aids in further mechanical and chemical digestion but is not the primary site for nutrient absorption. The large intestine's main function is to absorb water and electrolytes, not nutrients.

3. Which type of waves exhibit both longitudinal and transverse motion?

A. Electromagnetic waves
B. Surface waves
C. Mechanical waves
D. Sound waves

Correct answer: B

Rationale: Surface waves exhibit both longitudinal and transverse motion. These waves travel along the boundary between two different mediums, such as water and air, causing particles to move both parallel (longitudinal) and perpendicular (transverse) to the wave's direction of travel. This unique characteristic distinguishes surface waves from other types of waves, making them the correct answer in this context. Electromagnetic waves, like light and radio waves, are purely transverse in nature, propagating through vacuum or different media through oscillating electric and magnetic fields perpendicular to the direction of wave travel. Mechanical waves, including both transverse (e.g., water waves) and longitudinal (e.g., sound waves in air) waves, do not typically exhibit both types of motion simultaneously, unlike surface waves.

4. How do DNA and RNA function together as part of the human genome?

A. DNA carries genetic information from RNA to the cell cytoplasm.
B. RNA carries genetic information from DNA to the cell cytoplasm.
C. DNA and RNA carry genetic information from the cell nucleus to the cytoplasm.
D. DNA and RNA do not interact within the cell.

Correct answer: B

Rationale: The correct answer is B. RNA acts as a messenger carrying genetic instructions from the DNA in the nucleus to the cytoplasm, where proteins are synthesized. This process is known as transcription and translation, where DNA provides the blueprint for protein synthesis, and RNA delivers this information to the cellular machinery in the cytoplasm. Choice A is incorrect as it inaccurately states that DNA carries genetic information from RNA, which is the opposite of the actual flow of information. Choice C is incorrect as it suggests that both DNA and RNA together carry genetic information from the nucleus to the cytoplasm, which is not accurate. Choice D is incorrect as DNA and RNA do interact within the cell, playing crucial roles in genetic information processing and protein synthesis.

5. Which of the following is a constant?

A. The number of protons in an oxygen atom
B. The temperature at which iron ore will melt
C. The human population size
D. The time the sun rises each day

Correct answer: A

Rationale: The number of protons in an oxygen atom is a constant. This value is determined by the atomic number of the element and does not change regardless of the isotope of oxygen. The number of protons defines the element and remains consistent under normal conditions. Choices B, C, and D are not constants. The temperature at which iron ore will melt can vary depending on factors like pressure, the human population size is constantly changing, and the time the sun rises each day varies with the seasons and location.