Question 1

Which of the following best describes the process of sensory transduction in a sensory receptor?

Accepted Answer

The conversion of stimulus energy into a change in the membrane potential of a sensory receptor.

Question 2

A patient is unable to distinguish between sweet and umami tastes but can still detect sour, salty, and bitter. Which type of receptor is most likely malfunctioning?

Accepted Answer

G protein-coupled receptors (GPCRs)

Question 3

Which of the following statements about the sliding-filament model of muscle contraction is correct?

Accepted Answer

Thin and thick filaments slide past each other, powered by ATP hydrolysis by myosin.

Question 4

Which of the following best explains why mammals have a blind spot in their visual field?

Accepted Answer

The optic disk lacks photoreceptors, so light striking this region is not detected.

Question 5

A runner experiences muscle fatigue after a sprint. Which muscle fiber type is primarily responsible for this fatigue, and why?

Accepted Answer

Glycolytic fibers, because they rely on glycolysis and tire quickly.

Question 6

Which of the following is a function of the Eustachian tube in the mammalian ear?

Accepted Answer

Equalizes pressure between the middle ear and the nasopharynx.

Question 7

Which of the following best describes the role of calcium ions ($$\mathrm{Ca$$^{2+}$$}) in $$skeletal muscle contraction?

Accepted Answer

$$\mathrm{Ca$$^{2+}$$}$$ binds to the troponin complex, exposing myosin-binding sites on actin.

Question 8

Which of the following is true regarding the difference between rods and cones in the human retina?

Accepted Answer

Cones provide color vision and are concentrated in the fovea, while rods are more sensitive to low light.

Question 9

A fish uses its lateral line system to detect water movement. Which type of receptor is primarily involved in this process?

Accepted Answer

Mechanoreceptors

Question 10

Which of the following best explains why capsaicin (from hot peppers) causes a sensation of heat?

Accepted Answer

Capsaicin activates thermoreceptors that also respond to high temperatures by opening calcium channels.

Question 11

Which of the following is a key difference between exoskeletons and endoskeletons?

Accepted Answer

Exoskeletons are external coverings, while endoskeletons are internal structures buried in soft tissue.

Question 12

Which of the following best describes the process of sensory adaptation?

Accepted Answer

A decrease in responsiveness of a sensory receptor to continued stimulation.

Question 13

Which of the following is the correct sequence of events in the signal transduction pathway for muscle contraction?

Accepted Answer

Action potential in motor neuron → release of acetylcholine → depolarization of muscle fiber → release of $$\mathrm{Ca$$^{2+}$$}$$ from sarcoplasmic reticulum → binding of $$\mathrm{Ca$$^{2+}$$} to $$troponin → contraction

Question 14

Which of the following is a property of slow-twitch muscle fibers?

Accepted Answer

They have a high concentration of myoglobin and are adapted for endurance.

Question 15

Which of the following best explains why animals with hydrostatic skeletons are well suited for aquatic environments?

Accepted Answer

Fluid-filled compartments allow for flexible movement and support in water.

Question 16

Which of the following is true about the function of the statocyst in invertebrates?

Accepted Answer

It contains mechanoreceptors that detect the movement of statoliths, providing information about body position relative to gravity.

Question 17

Which of the following best describes the mechanism by which light causes hyperpolarization in vertebrate photoreceptors?

Accepted Answer

Light activates rhodopsin, which leads to the closure of $$\mathrm{Na^+}$$ channels via a G-protein cascade.

Question 18

Which of the following is a unique property of cardiac muscle compared to skeletal muscle?

Accepted Answer

Cardiac muscle cells are electrically connected by intercalated disks and can generate action potentials without neural input.

Question 19

Which of the following best explains why fast-swimming fish have a torpedo-like body shape?

Accepted Answer

To minimize friction and allow efficient movement through water.

Chapter 50: Sensory and Motor Mechanisms – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards