Psychology Chapter: Twin Studies and Genetics

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Questions and Answers

What is one of the main focuses of behavioral genetics?

Genetic mapping of diseases

The study of physical traits only

The interaction of genes and behavior (correct)

The impact of environmental factors only

What is the key concept in evolutionary psychology regarding behavior?

Behavior has adaptive significance linked to natural selection (correct)

Behavior is random and nonsensical

Behavior is solely determined by genetics

Behavior has no impact on reproductive success

In twin studies, what are researchers comparing?

Fraternal twins against non-twin siblings

Identical twins against fraternal twins (correct)

Behavioral tests of twins from different environments

Genetic mapping of twins and singletons

According to the interactionist model proposed by Rose, what do we inherit?

Dispositions that influence potential behavior Signup and view all the answers

Which of the following best describes genetic mapping?

Locating specific genes within the human genome Signup and view all the answers

Which neurotransmitter is primarily associated with regulating mood and arousal?

Norepinephrine Signup and view all the answers

What is the primary role of dopamine in the nervous system?

Voluntary movement Signup and view all the answers

What does an antagonist do in the context of neurotransmitters?

Opposes the action of neurotransmitters Signup and view all the answers

Which of the following neurotransmitters is critical for sleep and wakefulness?

Serotonin Signup and view all the answers

Which neurotransmitter is considered an inhibitor and helps regulate anxiety?

GABA Signup and view all the answers

Which structure connects the two cerebral hemispheres?

Corpus callosum Signup and view all the answers

What type of processing is primarily associated with the left hemisphere?

Verbal processing Signup and view all the answers

What hormone is produced by the pancreas to lower blood sugar levels?

Insulin Signup and view all the answers

What is aphasia?

An impairment in language production and understanding Signup and view all the answers

Which area of the brain is associated with language production?

Broca's area Signup and view all the answers

Which hormone is responsible for salt and carbohydrate metabolism?

Cortisol Signup and view all the answers

How many pairs of chromosomes do humans have?

23 Signup and view all the answers

In split-brain research, what happens when an image is shown to the right visual field?

The subject can verbally identify the object Signup and view all the answers

What is the term for genetic traits that can be either homozygous or heterozygous?

Alleles Signup and view all the answers

What type of processing is the right hemisphere primarily responsible for?

Visual recognition and music. Signup and view all the answers

Which of the following hormones is not secreted by the gonads?

Norepinephrine Signup and view all the answers

What can be a consequence of cutting the corpus callosum?

Inability to transfer sensory information between hemispheres Signup and view all the answers

What type of inheritance involves multiple genes influencing a single trait?

Polygenic inheritance Signup and view all the answers

Which part of the brain is primarily responsible for sensory perception and integration?

Somatosensory cortex Signup and view all the answers

Which of the following statements about the two cerebral hemispheres is true?

They are specialized for different types of processing. Signup and view all the answers

What does a family study primarily investigate in the context of genetics?

Heritability of traits Signup and view all the answers

What is the basic unit of heredity found on chromosomes?

Gene Signup and view all the answers

Who conducted influential split-brain research that earned a Nobel Prize?

Roger Sperry Signup and view all the answers

What is the primary role of the pituitary gland in the endocrine system?

It secretes substances that influence other glands. Signup and view all the answers

Which of the following hormones is secreted by the pituitary gland?

Growth Hormone (GH) Signup and view all the answers

What does negative feedback in the endocrine system accomplish?

It allows the body to maintain hormone levels by stopping secretion at a certain point. Signup and view all the answers

Which lobe of the brain is primarily involved in visual processing?

Occipital lobe Signup and view all the answers

Which of the following functions is NOT associated with the occipital lobe?

Memory processing Signup and view all the answers

What is the primary role of the thyroid gland in the endocrine system?

Regulates metabolic rate. Signup and view all the answers

Which function does NOT relate to spatial awareness?

Prosody in language Signup and view all the answers

Which lobe of the brain is most involved in auditory processing?

Temporal lobe Signup and view all the answers

Study Notes

Twin Studies

Identical twins are monozygotic and share 100% of their genes.
Fraternal twins are dizygotic and share 50% of their genes, similar to siblings born at different times.
Twin studies compare resemblance of identical and fraternal twins to examine relative contributions of genetics and environment to traits.
Adoption studies compare adopted children to their biological and adoptive parents to determine genetic and environmental influences.

Modern Approaches to Nature vs. Nurture Debate

Molecular Genetics: Investigates the biochemical basis of genetic inheritance.
The Human Genome Project (2003): Mapped the entire human genome, identifying the location of specific genes.
Genetic Mapping: Locating specific genes on chromosomes to study their role in various traits.

Behavioral Genetics

The Interactionist Model: Emphasizes that genes and environment interact to influence behavior.
Richard Rose (1995): "We inherit dispositions, not destinies."
Behavioral genetics: Examines how genes influence behavioral traits.

Evolutionary Psychology

Focuses on understanding the evolutionary history of behaviors and their adaptive significance.
Based on Darwin's theory of natural selection – traits that enhance reproductive success are more likely to be passed down.
Adaptions: Behavioral and physical traits that contribute to survival and reproductive success.
Examples: Flight-or-fight response, taste preferences, parental investment, mating strategies.

Alzheimers Disease

Impacts the brain, affecting motor neurons and voluntary muscle control.
Implicated in memory and attention deficits.

Neurotransmitters

Chemical messengers that transmit signals between neurons at synapses.
Lock-and-Key Mechanism: Neurotransmitters bind to specific receptors on the receiving neuron.
Agonist: Mimics the actions of neurotransmitters; example is nicotine.
Antagonist: Opposes the actions of neurotransmitters; example is curare.
Interactions between Neurotransmitter Circuits are critical for brain function.

Monoamines

Norepinephrine (NE): Found in CNS and PNS neurons, modulates mood, arousal, learning, and memory.
Serotonin (5-HT): Involved in sleep-wakefulness cycles, implicated in aggression, eating disorders, and mood regulation.
Dopamine (DA): Essential for voluntary movement and reward systems.

Amino Acids

GABA (gamma-aminobutyric acid) and Glycine: Major inhibitory neurotransmitters, regulating anxiety, seizure expression, and sleep modulation.

The Brain

Cerebrum: Two hemispheres, divided into four lobes, responsible for higher cognitive functions.
Cerebral Hemispheres: Two specialized halves of the brain, connected by the corpus callosum.
Longitudinal Fissure: Divides the two hemispheres.
Left Hemisphere: Dominates verbal processing: language, speech, reading, and writing.
Right Hemisphere: Focuses on nonverbal processing: spatial awareness, musical abilities, visual recognition.

Aphasia

Impairment in language production and understanding, including reading and writing.
Broca's Area: Located in the left frontal lobe, crucial for speech production.
Wernicke's Area: Situated in the left temporal lobe, responsible for language comprehension.

Split-Brain Research

Roger Sperry (1981 Nobel Prize): Conducted research on patients with severed corpus callosums (split-brain patients).
Severed Corpus Callosum: Prevents sensory information from transferring between hemispheres.
Consequences: Limited communication between hemispheres, affecting perception and behavior.
Visual Field Identification: Research showed that each hemisphere specializes in different tasks:
- Right visual field = verbal identification.
- Left visual field = manual identification.
- Object in right hand = verbal identification.
- Object in left hand = nonverbal identification.

Frontal Lobe

Sensory perception and integration: Processes through the somatosensory cortex.
Spatial awareness and navigation.
Visuospatial processing.
Math, logic, and language.

Temporal Lobe

Audition, language, prosody (emotional tone in speech).
Memory, emotional processing.
Object recognition, smell processing.
Facial recognition.

Occipital Lobe

Vision: Processes visual information, including perception, spatial awareness, color recognition, movement detection, and pattern recognition.
Visual attention and focus.

Endocrine System

Hormones: Chemical messengers secreted into the bloodstream, influencing various bodily functions.
Negative Feedback: Mechanism regulating hormone secretion by shutting down production when levels reach a threshold.

Important Endocrine Glands

Pituitary Gland: "Master gland" secreting hormones that influence other glands and bodily functions; examples include growth hormone (GH) and oxytocin.
Thyroid Gland: Controls metabolic rate by secreting T4, T3, and calcitonin hormones.
Adrenal Glands: Regulate salt and carbohydrate metabolism, produce cortisol, aldosterone, epinephrine, and norepinephrine.
Pancreas: Secretes insulin and glucagon to regulate blood sugar metabolism.
Gonads: Secrete sex hormones: testosterone (males), estrogen and progesterone (females).

Genes and Behavior

Behavioral Genetics: Study of how genes influence behavioral traits.
Chromosomes: Strands of DNA carrying genetic information; humans have 23 pairs (except gametes).
Genes: Segments of DNA located on chromosomes, carrying instructions for building proteins and influencing traits.
Dominant vs. Recessive Genes: Determine gene expression and trait expression.
Homozygous vs. Heterozygous: Refer to the pairs of genes, affecting trait expression.
Genotype: Genetic make-up.
Phenotype: Observable characteristics.
Polygenic Inheritance: Traits influenced by multiple genes.

Research Methods in Behavioral Genetics

Family Studies: Examine trait prevalence among family members to assess genetic influences.
Twin Studies: Compare identical and fraternal twins to determine the relative contributions of genes and environment.
Adoption Studies: Compare traits of adopted children to their biological and adoptive parents to disentangle genetic and environmental influences.

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Description

Explore the fascinating world of twin studies and the modern approaches to the nature versus nurture debate. This quiz delves into the differences between identical and fraternal twins, the impact of genetics and environment on traits, and significant contributions from molecular genetics and the Human Genome Project.