TEAS 7 Biology: Master Key Concepts

ATI TEAS 7

Biology

1. What is the difference between DNA and RNA?

A. Both are double-stranded.
B. DNA contains deoxyribose sugar, while RNA contains ribose sugar.
C. RNA contains the nitrogenous base uracil, while DNA contains thymine.
D. Both are identical molecules.

Correct answer: B

Rationale: Rationale: A) Incorrect. DNA is double-stranded, but RNA is typically single-stranded. B) Correct. DNA contains deoxyribose sugar, which lacks an oxygen atom on the 2' carbon of the sugar ring, while RNA contains ribose sugar, which has an additional hydroxyl group on the 2' carbon. C) Incorrect. RNA contains the nitrogenous base uracil, while DNA contains thymine. D) Incorrect. DNA and RNA have distinct structures and functions, so they are not identical molecules.

2. The involuntary "fight-or-flight" response is controlled by the:

A. Sympathetic nervous system
B. Parasympathetic nervous system
C. Enteric nervous system
D. Sensory nervous system

Correct answer: A

Rationale: The correct answer is A: Sympathetic nervous system. The "fight-or-flight" response is an automatic physiological reaction triggered by the sympathetic nervous system in response to a perceived threat or stressor. This system prepares the body for action by increasing heart rate, dilating pupils, and redirecting blood flow to muscles. The parasympathetic nervous system, on the other hand, controls the body's "rest-and-digest" response, promoting relaxation and digestion. The enteric nervous system primarily regulates the gastrointestinal system, while the sensory nervous system is responsible for transmitting sensory information to the brain. Therefore, the sympathetic nervous system is specifically responsible for initiating the fight-or-flight response.

3. The important decision will be made tomorrow. Which word is the comparative form of the adjective "important"?

A. important
B. importantly
C. more important
D. most important

Correct answer: C

Rationale: The comparative form of an adjective compares two things.

4. The involuntary reflex arc that withdraws your hand from a hot object involves the:

A. Central nervous system only
B. Peripheral nervous system only
C. Both CNS and PNS
D. Sensory neurons only

Correct answer: C

Rationale: The correct answer is C: 'Both CNS and PNS'. This is because the reflex arc involves both the central nervous system (CNS) and the peripheral nervous system (PNS). The sensory neurons in the PNS detect the stimulus (hot object), then send signals to the spinal cord in the CNS. The spinal cord processes the information and immediately sends a motor response signal back out through the PNS to move the hand away from the hot object. This rapid and involuntary response demonstrates the coordination between the CNS and PNS in executing the reflex arc.

5. Which division of the peripheral nervous system is responsible for transmitting signals from the central nervous system to skeletal muscles, enabling voluntary muscle movements?

A. Somatic nervous system
B. Autonomic nervous system
C. Sympathetic nervous system
D. Parasympathetic nervous system

Correct answer: a

Rationale: The correct answer is A: Somatic nervous system. The somatic nervous system is responsible for transmitting signals from the central nervous system to skeletal muscles, allowing for voluntary muscle movements. This division controls conscious movements such as walking, talking, and picking up objects. The autonomic nervous system (option B) controls involuntary functions like heart rate and digestion, while the sympathetic (option C) and parasympathetic (option D) nervous systems are subcategories of the autonomic system and regulate the body's responses to stress and relaxation, respectively. Therefore, the somatic nervous system is the correct division responsible for voluntary muscle movements.