Question 1

Which of the following best describes how steroid hormones typically exert their effects on target cells?

Accepted Answer

They diffuse through the plasma membrane and bind to intracellular receptors, influencing gene expression.

Question 2

A patient has a tumor that causes excessive secretion of parathyroid hormone (PTH). Which of the following is the most likely effect on blood calcium levels, and what feedback mechanism is involved?

Accepted Answer

Blood calcium levels increase, but negative feedback is disrupted by the tumor.

Question 3

Which of the following is an example of negative feedback in hormonal regulation?

Accepted Answer

High blood glucose stimulates insulin release, which lowers blood glucose and inhibits further insulin secretion.

Question 4

Which of the following best describes the difference between asexual and sexual reproduction?

Accepted Answer

Asexual reproduction produces genetically identical offspring, while sexual reproduction increases genetic diversity.

Question 5

During fertilization in animals, which process ensures that only one sperm fertilizes the egg?

Accepted Answer

The cortical reaction modifies the egg membrane to prevent polyspermy.

Question 6

Which hormone is primarily responsible for triggering ovulation in the human female reproductive cycle?

Accepted Answer

Luteinizing hormone (LH)

Question 7

Which of the following correctly describes the sequence of early embryonic development in animals?

Accepted Answer

Cleavage → Gastrulation → Organogenesis

Question 8

A mutation causes a neuron to lack functional voltage-gated sodium channels. What is the most likely effect on the neuron's ability to transmit signals?

Accepted Answer

The neuron will be unable to generate action potentials.

Question 9

Which equation best represents the Nernst equation for calculating the equilibrium potential ($$E_{ion}) $$for a particular ion across a membrane?

Accepted Answer

$$E_{ion} = \frac{RT}{zF} \ln \left( \frac{[ion]_{outside}}{[ion]_{inside}} \right)$$

Question 10

Which brain region is primarily responsible for regulating basic life functions such as breathing and heart rate?

Accepted Answer

Medulla oblongata

Question 11

A patient suffers a stroke that damages the left motor cortex. Which of the following is the most likely result?

Accepted Answer

Impaired voluntary movement on the right side of the body

Question 12

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

Accepted Answer

Conversion of a sensory stimulus into a change in membrane potential

Question 13

Which structure in the vertebrate ear is responsible for detecting rotational movement and maintaining equilibrium?

Accepted Answer

Semicircular canals

Question 14

Which of the following correctly outlines the pathway of visual information from detection to processing in the vertebrate nervous system?

Accepted Answer

Photoreceptors → Optic nerve → Thalamus → Visual cortex

Question 15

Which of the following best explains how muscle contraction is powered at the molecular level?

Accepted Answer

ATP hydrolysis provides energy for myosin heads to move along actin filaments.

Question 16

Which of the following statements best compares the hydrostatic skeleton of an earthworm to the endoskeleton of a human?

Accepted Answer

The hydrostatic skeleton uses fluid-filled compartments for support, while the endoskeleton uses mineralized tissue.

Question 17

Which of the following best describes the role of chemoreceptors in taste and smell?

Accepted Answer

They respond to specific chemical molecules, initiating sensory signals.

Question 18

A scientist observes that blocking the sodium-potassium pump in a neuron leads to a gradual loss of the resting membrane potential. Which equation describes the pump's action?

Accepted Answer

$$3 	ext{Na}^+_{out} / 2 	ext{K}^+_{in}$$ exchanged per ATP hydrolyzed

Question 19

Which of the following scenarios best illustrates the integration of the nervous and endocrine systems in maintaining homeostasis?

Accepted Answer

The hypothalamus detects low body temperature and signals the pituitary to release thyroid-stimulating hormone (TSH).

BIO 123 Exam 3 Study Guide: Hormones, Reproduction, Development, Nervous and Sensory Systems

Study Guide - Practice Questions

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