PSYCH 111: Introduction to Psychology: Week 7: Chapter 3 Quizzes: Biopsychology

The Correct Answer is:

B. A dominant allele will determine the phenotype if inherited from one parent (Bb) or both parents (BB), while a recessive trait appears only when two recessive alleles (bb) are present

A dominant allele expresses its associated phenotype whenever it is present, whether inherited from one parent (heterozygous, Bb) or both parents (homozygous dominant, BB). A recessive trait only appears when the individual has two copies of the recessive allele (homozygous recessive, bb). For example, smooth chin is a recessive trait and will only be displayed when both alleles are recessive (bb).

Why the other options are incorrect:

A. A dominant allele only affects the phenotype if inherited from both parents

This is incorrect because a single dominant allele is enough to express the dominant trait. For example, someone with Bb will still show the dominant phenotype.

C. Recessive alleles are always stronger than dominant alleles and control all physical traits

This is incorrect because dominant alleles override recessive alleles when present. Recessive traits are only expressed when both alleles are recessive.

D. Heterozygous individuals always display a mixture of dominant and recessive traits equally

This is incorrect because heterozygous individuals (Bb) express only the dominant phenotype, not a blend of dominant and recessive traits.

The Correct Answer is:

B. They treat psychiatric symptoms by restoring neurotransmitter balance

Psychotropic medications are drugs used to manage psychiatric symptoms by targeting chemical imbalances in the brain. They work by affecting neurotransmitter activity, either increasing, decreasing, or stabilizing the levels of key chemicals like serotonin, dopamine, and norepinephrine. By restoring this balance, these medications help reduce symptoms of mental health disorders such as depression, anxiety, schizophrenia, and bipolar disorder, improving overall emotional and cognitive functioning.

Why the other options are incorrect:

A. They permanently change brain structure to eliminate mental illnesses

This is incorrect because psychotropic medications do not permanently alter brain structure. Instead, they temporarily modify neurotransmitter activity to manage symptoms. Structural changes in the brain are not their primary goal, and symptoms can return if medication is stopped without proper treatment planning.

C. They cure all psychological disorders by enhancing cognitive processes

This is incorrect because psychotropic medications do not cure all mental health disorders, nor do they primarily enhance cognitive functioning. Instead, they manage symptoms by balancing neurotransmitter activity. Some disorders may require additional interventions like psychotherapy, behavioral therapy, or lifestyle modifications for effective treatment.

D. They replace natural hormones to regulate mood and behavior

This is incorrect because psychotropic medications work on neurotransmitters, not hormones. While hormones affect mood, these medications specifically alter chemical communication in the brain. They do not function like hormonal replacements but instead restore proper neurotransmitter signaling to stabilize emotional and psychological states.

The Correct Answer is:

B. The cerebellum controls balance, coordination, motor skills, and supports procedural memory

The cerebellum, located at the back of the brain, receives information from muscles, joints, tendons, and inner ear structures to maintain balance, coordination, and fine motor skills. It is also closely linked to procedural memory, which involves learning and remembering how to perform tasks, such as riding a bike or playing an instrument. Research on H.M.’s case showed that despite his inability to form new explicit memories, his intact cerebellum allowed him to learn new motor-based tasks.

Why the other options are incorrect:

A. The cerebellum regulates emotional responses and decision-making abilities

This is incorrect because emotional regulation and decision-making are primarily managed by the frontal lobe and the limbic system, not the cerebellum. While the cerebellum coordinates movement, it does not control personality traits or higher-level reasoning.

C. The cerebellum processes language comprehension and auditory information exclusively

This is incorrect because language comprehension is primarily managed by Wernicke’s area in the temporal lobe, and auditory processing also occurs in the temporal lobe. The cerebellum’s primary role is coordinating movement and supporting procedural memory, not interpreting spoken language or sounds.

D. The cerebellum forms explicit memories and stores long-term personal experiences

This is incorrect because explicit memories, such as personal events or factual information, are mainly processed by the hippocampus and associated temporal lobe structures. The cerebellum focuses on procedural memories, which involve motor learning, rather than conscious recollection of experiences.

The Correct Answer is:

B. Because electrical impulses travel along the axon, while neurotransmitters cross the synaptic gap

Neuronal communication is considered an electrochemical event because it involves two interconnected processes. The electrical process begins when an action potential travels along the axon, caused by ion exchange across the neuron’s membrane. When this electrical signal reaches the axon terminal, it triggers the release of neurotransmitters into the synaptic cleft. These neurotransmitters then bind to receptors on the next neuron, allowing the signal to continue. Both electrical and chemical steps are essential for proper communication.

Why the other options are incorrect:

A. Because the brain uses only neurotransmitters to send messages between neurons

This is incorrect because neurotransmitters alone cannot transmit signals without the initial electrical impulse traveling along the axon. The electrical action potential is what triggers the release of neurotransmitters, making both electrical and chemical processes necessary for communication.

C. Because neurons communicate using hormones released into the bloodstream

This is incorrect because hormones are part of the endocrine system and are not the primary method of neuron-to-neuron communication. Hormonal signaling is much slower and affects multiple systems, whereas neurotransmitter-based signaling is rapid, precise, and specifically designed for quick communication between neurons.

D. Because communication in neurons relies entirely on electrical charges without chemical involvement

This is incorrect because although the action potential is electrical, the signal cannot cross the synaptic cleft without neurotransmitters. The chemical process bridges the gap between neurons, making the chemical phase just as vital as the electrical one in maintaining proper signal transmission.

The Correct Answer is:

B. The thyroid gland releases hormones that regulate growth, metabolism, and appetite, and excess thyroxine leads to hyperthyroidism

The thyroid gland, located in the neck, produces hormones like thyroxine (T4) and triiodothyronine (T3) that regulate the body’s growth, metabolism, and appetite. When the thyroid becomes overactive, as in Grave’s disease, it releases excessive amounts of thyroxine. This leads to symptoms such as weight loss, bulging eyes, irritability, nervousness, and increased heart rate. Proper thyroid function is essential for maintaining energy balance and overall metabolic health.

Why the other options are incorrect:

A. The thyroid gland regulates balance and coordination by controlling motor neurons

This is incorrect because balance and coordination are functions of the cerebellum, not the thyroid gland. The thyroid regulates hormone production affecting metabolism and energy levels rather than controlling direct motor movements.

C. The thyroid gland stores neurotransmitters and supports voluntary muscle movements

This is incorrect because neurotransmitter storage and voluntary motor control are functions of the nervous system, specifically the somatic nervous system, not the thyroid. The thyroid’s role is hormonal regulation, not neural signaling.

D. The thyroid gland processes sensory information and interprets visual signals

This is incorrect because sensory and visual processing occur in the parietal lobe and occipital lobe of the brain, not in the thyroid gland. The thyroid primarily regulates metabolic and hormonal functions rather than interpreting environmental stimuli.

The Correct Answer is:

b. myelin sheath

Multiple sclerosis (MS) is a chronic autoimmune disorder in which the immune system attacks the myelin sheath, the protective covering surrounding the axons of neurons. The breakdown of myelin disrupts the efficient transmission of electrical impulses between neurons, leading to slowed or blocked communication within the nervous system. This results in symptoms such as muscle weakness, fatigue, balance problems, vision disturbances, and difficulty with coordination and motor control.

Why the other options are incorrect:

a. soma

This is incorrect because the soma, or cell body, processes information but is not directly affected in multiple sclerosis. While communication problems eventually impact the soma’s ability to integrate signals, the disease primarily targets the myelin covering the axons.

c. synaptic vesicles

This is incorrect because synaptic vesicles store and release neurotransmitters into the synaptic cleft. Multiple sclerosis does not damage vesicles directly but disrupts electrical signaling before neurotransmitter release occurs.

d. dendrites

This is incorrect because dendrites are responsible for receiving incoming signals from other neurons. In MS, dendrites are not the main site of damage. The disease specifically attacks the myelin along the axons, impairing signal transmission rather than blocking dendritic input.

The Correct Answer is:

C. Epigenetics

Epigenetics is the field of study that explores how environmental factors influence gene expression without altering the DNA sequence itself. It examines how experiences, diet, stress, toxins, and other external factors can “switch” genes on or off, leading to differences in traits and behaviors. Epigenetic mechanisms, such as DNA methylation and histone modification, explain how individuals with the same genotype can develop different phenotypes. This field bridges genetics, psychology, and environment in understanding human development and health.

Why the other options are incorrect:

A. Social psychology

This is incorrect because social psychology focuses on how people’s thoughts, behaviors, and emotions are influenced by others and social contexts. It does not study genes or their expression.

B. Evolutionary psychology

This is incorrect because evolutionary psychology studies how behaviors and mental processes evolved over time to enhance survival and reproduction. While related to genetics, it does not focus on gene expression specifically.

D. Behavioral neuroscience

This is incorrect because behavioral neuroscience studies the relationship between the brain, nervous system, and behavior. While it looks at biological processes, it does not primarily examine how environmental factors regulate gene expression like epigenetics does.

The Correct Answer is:

d. substantia nigra

The substantia nigra is located in the midbrain, not the forebrain. It plays a crucial role in producing dopamine, which regulates movement, coordination, and reward pathways. Damage to this area, such as in Parkinson’s disease, leads to motor control issues due to reduced dopamine production. While the forebrain handles higher-order functions like learning, memory, and emotion, the substantia nigra belongs to a different brain region responsible for motor regulation.

Why the other options are incorrect:

a. thalamus

This is incorrect because the thalamus, part of the forebrain, acts as the brain’s sensory relay station, sending sensory information (except smell) to the appropriate cortical regions for processing.

b. hippocampus

This is incorrect because the hippocampus, also part of the forebrain, is essential for forming and storing explicit memories and plays a role in spatial navigation and learning.

c. amygdala

This is incorrect because the amygdala, located in the forebrain, is heavily involved in emotion regulation, especially fear, aggression, and emotional memory formation.

The Correct Answer is:

B. Organisms better suited to their environment are more likely to survive and reproduce, while those poorly suited are less likely to pass on their genes

Darwin’s theory of natural selection explains that organisms with favorable traits that give them an advantage in their environment are more likely to survive, reproduce, and pass those traits to future generations. Over time, this process shapes species by favoring adaptations that improve survival and reproductive success, while traits that do not offer advantages gradually disappear from the population.

Why the other options are incorrect:

A. Organisms evolve based on their individual desires and choices

This is incorrect because evolution is not a conscious process. Organisms cannot intentionally change their traits to survive; natural selection operates through heritable genetic variation, not personal effort.

C. Evolution occurs randomly without any relationship to environmental pressures

This is incorrect because, while genetic mutations can occur randomly, natural selection is not random. The environment determines which traits are advantageous, shaping survival and reproduction outcomes

D. Organisms adapt to their environments by intentionally changing their physical traits during their lifetime

This is incorrect because traits acquired during a single lifetime are not inherited. This idea reflects Lamarck’s theory, not Darwin’s. For example, a giraffe stretching its neck won’t pass the longer neck to its offspring; only genetic variations that provide advantages are naturally selected.