Book cover for Psychology Openstax

Psychology Openstax

Rosie M. Spielman

ISBN #9781938168352

1st Edition

587 Questions

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123,165 Students Helped

Homework Questions

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Summary
Learning Objectives
Key Concepts
Example Problems
Explanations
Common Mistakes

Summary

Chapter 3 on Biopsychology integrates key principles of human genetics, the nervous system, and the endocrine system to reveal the biological basis of behavior and health. By emphasizing natural selection's role in genetic diversity, detailing the mechanics of neuronal communication through action potentials and synapses, and explaining the long-term regulatory impacts of hormones, the chapter provides a comprehensive understanding of how biological systems interact to influence human behavior.

Learning Objectives

1

Explain the fundamental concepts of human genetics and how natural selection contributes to genetic diversity.

2

Describe the detailed structure and function of the nervous system, including neuronal communication via action potentials and synapses.

3

Understand the role and mechanisms of the endocrine system in regulating physiological processes over longer durations.

4

Integrate the concepts of genetics, neural communication, and hormonal regulation to explain the biological basis of behavior and health.

Key Concepts

CONCEPT

DEFINITION

Human Genetics

The study of genes, genetic variation, and heredity in human beings, including the influence of natural selection on genetic diversity.

Natural Selection

A process by which organisms better adapted to their environment tend to survive and produce more offspring, thereby maintaining and spreading genetic diversity.

Nervous System

A complex network of neurons and supporting cells that regulate bodily functions and enable communication throughout the body via electrical signals.

Neuronal Communication

The process by which neurons transmit signals through action potentials and synaptic transmission, enabling rapid and precise communication.

Action Potential

A fast, transient electrical impulse that travels along the neuron's membrane, initiating the transmission of information.

Synapse

The junction between neurons where neurotransmitters are released to transmit signals from one neuron to another.

Endocrine System

A collection of glands that produce hormones, which regulate long-term physiological processes by releasing chemical signals into the bloodstream.

Example Problems

Example 1

A(n) ________ is a sudden, permanent change in a sequence of DNA. a. allele b. chromosome c. epigenetic d. mutation

Example 2

________ refers to a person’s genetic makeup,while ________ refers to a person’s physical characteristics. a. Phenotype; genotype b. Genotype; phenotype c. DNA; gene d. Gene; DNA

Example 3

________ is the field of study that focuses on genes and their expression. a. Social psychology b. Evolutionary psychology c. Epigenetics d. Behavioral neuroscience

Example 4

Humans have ________ pairs of chromosomes. a. 15 b. 23 c. 46 d. 78

Example 5

The ________ receive(s) incoming signals from other neurons. a. soma b. terminal buttons c. myelin sheath d. dendrites
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Step-by-Step Explanations

QUESTION

How does natural selection contribute to maintaining genetic diversity in human populations?

STEP-BY-STEP ANSWER:

Step 1: Identify genetic variations present within a population.
Step 2: Recognize that natural selection favors traits that enhance survival and reproduction.
Step 3: Understand that individuals with advantageous traits are more likely to reproduce, passing on their genes.
Step 4: Realize that this selective process maintains and promotes genetic diversity over generations.
Final Answer: Natural selection filters genetic variations by favoring traits that provide an adaptive advantage, thus maintaining and even enhancing genetic diversity in human populations.

Natural Selection and Genetic Diversity

QUESTION

What are the sequential steps involved in the generation and propagation of an action potential?

STEP-BY-STEP ANSWER:

Step 1: The neuron is at its resting membrane potential, maintained by ion channels and pumps.
Step 2: A stimulus causes a depolarization of the neuronal membrane.
Step 3: Once the depolarization reaches a threshold, voltage-gated sodium channels open, leading to a rapid influx of Na+ ions.
Step 4: The rising phase results in the peak of the action potential.
Step 5: Voltage-gated potassium channels open, allowing K+ ions to exit the neuron, which initiates repolarization.
Step 6: The membrane potential is restored to its resting state during the hyperpolarization and subsequent return phase.
Final Answer: The generation of an action potential involves a sequence of depolarization, threshold triggering, rapid rising due to Na+ influx, followed by repolarization from K+ efflux, culminating in the restoration of the resting membrane potential.

Action Potential in Neuronal Communication

QUESTION

How do hormones regulate body functions over a longer duration compared to neural signals?

STEP-BY-STEP ANSWER:

Step 1: Endocrine glands synthesize and secrete hormones into the bloodstream.
Step 2: Hormones travel through the circulatory system to reach specific target tissues.
Step 3: Upon reaching target cells, hormones bind to specific receptors, triggering intracellular signaling cascades.
Step 4: These cascades result in long-term changes in cellular activities and metabolism.
Final Answer: Hormones, released by endocrine glands into the bloodstream, bind to receptors in target tissues and trigger prolonged cellular responses, thereby regulating body functions over extended periods.

Hormonal Regulation via the Endocrine System

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Common Mistakes

  • Confusing the rapid signaling of the nervous system with the slower, prolonged effects of the endocrine system.
  • Oversimplifying natural selection and not recognizing its role in maintaining genetic diversity.
  • Misinterpreting the phases of an action potential or the mechanisms underlying synaptic transmission.
  • Failing to integrate the roles of genetics, neural mechanisms, and hormonal regulation into a cohesive understanding of behavior and health.