Week 1 Tutorial PSY/340 Biological Foundations of Psychology

Genetics and Heritability

Genetics 19th century monk Gregor Mendel developed what became known as Mendelian Genetics Demonstrated that inheritance occurs through genes Genes are aligned along chromosomes and come in pairs A gene is a portion of a chromosome and is composed of deoxyribonucleic acid (DNA) DNA serves as a model for the synthesis of ribonucleic acid (RNA) RNA is a single strand chemical that can serve as a template/ model for the synthesis of proteins Proteins determine the development of the body by: Forming part of the structure of the body Serving as enzymes, biological catalysts that regulate chemical reactions in the body

Genetics Two main types of chromosomal pairs: Homozygous – a person has an identical pair of genes on the 2 chromosomes Heterozygous – a person has an unmatched pair of genes on the two chromosomes Genes are either Dominant or Recessive Dominant – shows a strong effect in either the homozygous or heterozygous Recessive – shows its effect only in the homozygous condition

Genetics Types of Genes: Autosomal genes: all other genes except for sex- linked genes Sex-linked genes: genes located on the sex chromosomes During reproduction: Females contribute an X chromosome Males contribute either an X or a Y chromosome that determines the sex of the child The human Y chromosome has genes for 27 proteins, while the X chromosome has genes for approximately 1500 proteins. The reason why sex-linked genes usually refer to an X-linked gene. Sex-limited genes: genes that are present in both sexes but mainly have an effect on one sex (chest hair, breast size, etc.)

Heredity Heritability refers to how much characteristics depend on genetic differences Researchers have found evidence for heritability in almost every behavior they have tested Heritability of a certain trait is specific to a given population Strong environmental influences may cause genetic influences to have less of an effect

Heredity Research has found that genes do not directly produce behaviors Genes produce proteins that increase the probability that a behavior will develop under certain circumstances Genes can also have an indirect affect Genes can alter your environment by producing behaviors or traits that alter how people in your environment react to you

The Nervous System

The Nervous System Central nervous system (CNS): Control center of the nervous system Peripheral nervous system (PNS): connects the CNS to the rest of the body

The Nervous System Central nervous system (CNS) Includes the brain and the spinal cord Peripheral nervous system (PNS) Somatic nervous system: consists of axons conveying messages from the sense organs to the CNS and from the CNS to the muscles Autonomic nervous system: controls the heart, intestines, and other organs Has some cell bodies within the brain or spinal cord or in clusters along the sides of the spinal cord

The Lobes of the Brain

The Lobes of the Brain Normal text Bullet Sub-bullet

The Occipital Lobe Located at the posterior end of the cerebral cortex Also referred to as the striate cortex or the primary visual cortex Highly responsible for visual input Damage can result in cortical blindness

The Parietal Lobe Contains the primary somatosensory cortex Primary target for touch sensations and information from muscle-stretch receptors and joint receptors Also responsible for processing and integrating information about eye, head and body positions from information sent from muscles and joints

The Temporal Lobe Located on the lateral portion of each hemisphere near the temples Target for auditory information and essential for processing spoken language Also responsible for complex aspects of vision, including movement and some emotional and motivational behaviors Klüver-Bucy syndrome associated with temporal lobe damage

The Frontal Lobe Contains the prefrontal cortex and the precentral gyrus Precentral gyrus: also known as the primary motor cortex; responsible for the control of fine motor movement Prefrontal cortex: the integration center for all sensory information and other areas of the cortex Responsible for higher functions such as abstract thinking and planning Responsible for our ability to remember recent events and information People with damage to the prefrontal cortex exhibit delayed-response task: have to respond to something they see or hear after a delay

Applying What You Know

Match the name on the left with the structure on the right. Instructions Match the name on the left with the structure on the right. Keep trying until you get all answers correct.

Structures of the Brain Practice Medulla Pituitary Gland Amygdala Occipital Lobe Corpus Collosum Cerebellum Temporal Lobe Hypothalamus Hippocampus Cerebrum Frontal Lobe Parietal Lobe Spinal Cord Basal Ganglia Pons Thalamus