Question 1

Which of the following best describes the correct order of muscle structure from smallest to largest?

Accepted Answer

Myofibril → muscle fiber → fascicle → muscle

Question 2

During skeletal muscle contraction, which sarcomere regions change length and why?

Accepted Answer

The I band and H zone shorten because actin and myosin filaments slide past each other.

Question 3

Which of the following best explains why the cross-bridge cycle does NOT occur in a relaxed muscle?

Accepted Answer

Tropomyosin blocks the myosin-binding sites on actin, preventing cross-bridge formation.

Question 4

Which of the following best describes the role of ATP in the cross-bridge cycle?

Accepted Answer

ATP binds to myosin, causing it to detach from actin.

Question 5

A patient is unable to perform rapid, powerful movements but can sustain moderate activity for long periods. Which muscle fiber type is most likely deficient?

Accepted Answer

Fast-glycolytic fibers

Question 6

Which of the following statements about isometric and isotonic contractions is correct?

Accepted Answer

Isometric contractions generate tension without changing muscle length, while isotonic contractions change muscle length.

Question 7

Which of the following best describes the role of the sodium-potassium pump in maintaining the resting membrane potential?

Accepted Answer

It moves 3 Na$$^+$$ ions out and 2 K$$^+$$ ions in, maintaining the negative interior of the cell.

Question 8

Which glial cell is responsible for forming the myelin sheath in the central nervous system?

Accepted Answer

Oligodendrocyte

Question 9

During an action potential, which phase is characterized by the rapid influx of Na$$^+$$ ions?

Accepted Answer

Depolarization

Question 10

A neuron receives two simultaneous stimuli: one causes an EPSP and the other an IPSP. What is the likely result at the postsynaptic membrane?

Accepted Answer

The membrane potential will reflect the sum of both EPSP and IPSP, possibly canceling each other out.

Question 11

Which neurotransmitter is primarily released by postganglionic sympathetic neurons?

Accepted Answer

Norepinephrine

Question 12

Which of the following best describes the difference between white matter and gray matter in the central nervous system?

Accepted Answer

White matter contains myelinated axons, while gray matter contains neuron cell bodies.

Question 13

Which brain region is primarily responsible for regulating heart rate and breathing?

Accepted Answer

Medulla oblongata

Question 14

Which of the following is an example of negative feedback in homeostasis?

Accepted Answer

Shivering to increase body temperature when cold

Question 15

Which of the following best describes facilitated diffusion?

Accepted Answer

Movement of molecules down their concentration gradient via a membrane protein, without energy input

Question 16

Which of the following is true regarding the difference between mitosis and meiosis?

Accepted Answer

Mitosis produces two identical diploid cells, while meiosis produces four genetically unique haploid cells.

Question 17

Which of the following best describes the role of the plasma membrane in a cell?

Accepted Answer

It regulates the movement of substances into and out of the cell.

Question 18

Which of the following is a catabolic reaction?

Accepted Answer

The breakdown of glycogen into glucose molecules

Question 19

Which of the following best explains why action potentials are 'all-or-none' events, yet the nervous system can encode stimulus intensity?

Accepted Answer

Stronger stimuli increase the frequency of action potentials, not their amplitude.

Question 20

Which of the following best describes the adequate stimulus for a sensory receptor?

Accepted Answer

The specific type of energy to which a receptor is most sensitive

ANP Study Guide: Muscle and Nervous System, Homeostasis, Chemistry, and Cell Biology

Study Guide - Practice Questions

Study Guide - Flashcards