Module 1 Part 2: Biological Beginnings
Behavior genetics studies the role of genetic and environmental influences on behaviors. This field seeks to understand how genetics and the environment contribute to individual differences in behavior, including cognitive abilities, personality traits, and mental health conditions. Methods often include twin studies, family studies, and adoption studies to disentangle the influence of heredity and environment.
Chromosomes are structures within cells that contain DNA. Humans have 23 pairs of chromosomes, with one set inherited from each parent. Chromosomes play a crucial role in determining an individual's genetic makeup and can influence developmental processes and potential genetic disorders.
Deoxyribonucleic acid (DNA) is the molecule that carries genetic information in all living organisms. DNA is composed of two strands forming a double helix, with sequences of four types of nucleotides (adenine, thymine, cytosine, and guanine) that encode the genetic instructions for development, functioning, growth, and reproduction.
Meiosis is the process of cell division that results in the production of gametes (sperm and eggs) with half the number of chromosomes of the parent cell. This reduction division ensures that offspring have the same chromosome number as their parents and increases genetic diversity through recombination and independent assortment.
Mitosis is the process of cell division that results in two genetically identical daughter cells from a single parent cell. This process is essential for growth, development, and tissue repair in multicellular organisms.
A genotype is the genetic makeup of an individual organism. It refers to the specific alleles present at a particular gene locus or loci. The genotype, along with environmental factors, determines the phenotype, or observable characteristics, of an organism.
Genes are units of heredity made up of DNA that code for proteins and determine specific traits. Each gene is located at a specific position on a chromosome and can exist in different forms known as alleles. Genes influence both physical and behavioral traits.
Neurons are the basic working units of the brain and nervous system, responsible for receiving, processing, and transmitting information through electrical and chemical signals. Neurons play a critical role in all aspects of behavior and cognitive functioning.
Organogenesis is the process during embryonic development in which the organs are formed. This critical period occurs during the first trimester of pregnancy and involves the differentiation of cells into various tissues and organs.
A phenotype is the observable physical and behavioral characteristics of an organism, resulting from the interaction of its genotype with the environment. Examples include height, eye color, and susceptibility to certain diseases.
A teratogen is any agent that can cause birth defects or developmental abnormalities in a developing embryo or fetus. Teratogens include certain drugs, chemicals, infections, and environmental factors. The effect of a teratogen depends on the timing, dose, and duration of exposure.