Module 1: Introduction to Genetics I
Learning Objectives
- Discuss fundamental concepts of genetics including the structure of DNA, cell replication, mitosis, meiosis, and components of the central dogma
- Learn implications of how genetics as a social determinant of health impacts nursing practice
Tips for navigating the H5P Module
For the best viewing experience, please use Chrome or Firefox browsers.
Click the slides icon to view the list of slides.
Click the play icon, at the bottom of each slide, to start/stop the audio clip. It is set to automatically play for every slide except the first one.
Click the question mark button, on relevant slides, to review the definitions of key terms bolded on the slide.
Glossary
Alleles: Alternative forms of a gene that form from any genetic variation and are found at the same locus or place on a chromosome.
Allosomes: Sex chromosomes. Autosomal Dominant Inheritance (?): A pattern of genetic inheritance in which an individual requires one copy of an altered gene and one normal gene on a pair of autosomal or non-sex-linked chromosomes to exhibit the traits of the genetic disorder. At least one parent of the offspring must possess one copy of the altered gene.
Apoptosis: A form of programmed cell death which helps control growth and development in multicellular organisms.
Autosomal Recessive Inheritance: A pattern of genetic inheritance in which an individual needs two copies of the altered gene to manifest the genetic disorder. The parents of the offspring with an autosomal recessive inheritance must each carry at least one copy of the altered gene.
Autosomes: Any of the non-sex chromosomes in an organism; they contain several different genes, but these genes are not able to determine sex.
Cancer: A disease caused by uncontrolled growth of cells which can spread throughout the body.
Caspases: Caspases are a family of cysteine proteases that are activated during apoptosis and cleave damaged proteins, ultimately leading to cell death.
Cell Cycle: The stages that take place in a cell leading to duplication of its DNA (DNA replication) and division of cytoplasm and organelles to produce new cells.
Central Dogma: The two-step process of transcription and translation which converts gene information into proteins.
Checkpoint: A stage in the eukaryotic cell cycle at which the cell is examined to check for any cell damage, viral infection, or cancerous cell. The checkpoints induce a cell cycle arrest until the defects are repaired. These checkpoints occur near the end of G1, at the G2/M transition, and during metaphase.
Chromosomes: Structures of nucleic acids and proteins found in the nucleus of most living cells, which contain genetic information.
Codon: A sequence of three DNA or RNA nucleotides that are specific to an amino acid or stop signal during protein synthesis.
Congenital Abnormalities: Structural or functional disorders which occur prenatally or at birth; they can be detected later during infancy as well. Some examples include Down syndrome, cleft palate, and spina bifida.
Deletion Variation: A change in DNA sequence due to the removal of a base pair. This may alter the number of amino acids in a protein and its functionality.
Deoxyribonucleic Acid (DNA): The hereditary material in humans and almost all other organisms.
Dominant Alleles: One copy of a dominant allele is sufficient for expression of a trait. Dominant alleles mask recessive alleles.
Frameshift Variation: A change in the DNA sequence due to an insertion or deletion of a base pair. This alters the grouping of bases and changes the code for amino acids which usually creates a non-functional protein.
Gene: The basic unit of heredity, which is passed on from parents to offspring and determines specific traits for individuals.
Genetics: The study of the effects of individual genes and their influence on relatively rare single-gene disorders.
Genome: The entire sequence of our genes or genetic information contained in a cell.
Genomics: The study of all the genes in the genome, including interactions between genes, interactions between genes and environmental factors, and the impact of other psychosocial and cultural factors.
Genotype: The genetic makeup of an individual organism that determines its traits.
Germline Variations: Any alteration that occurs in gametes or germ cells which affects every cell of the body and can be passed onto the offspring.
Hereditary Variation: Genetic alterations that are inherited from parents and present in every cell of an organism. The variations are present in the germ cells (sperm and egg) of the parents and are passed on to their offspring through reproduction.
Homologous Pairs: Sets of chromosomes, one inherited from each parent, that possess the same genes but with different versions, or alleles, of those genes. These pairs go through genetic recombination during meiosis, which contributes to genetic diversity in the offspring.
Insertion Variation: A change in DNA sequence due to the addition of a base pair. This may alter the number of amino acids in a protein and its functionality.
Meiosis: The cell division process of making egg and sperm cells.
Missense Variation: A change in the DNA base sequence that results in a different amino acid than the previous one, altering protein synthesis.
Mitosis: The cell division process of making somatic cells.
Monogenic Inheritance: The inheritance of a specific trait from a parent to their offspring, which is determined by the expression of a single gene or allele rather than by multiple genes.
Nonsense Variation: A change in the DNA base sequence that causes the DNA sequence to change into a stop codon. This signals the cell to stop building the protein, and it results in a shortened protein which may or may not function effectively.
Nucleus: The central organelle of a eukaryotic cell, which usually contains the cell’s DNA.
Oncogenes: Genes that function to allow normal cell growth. When oncogenes are activated, they inhibit cell apoptosis and cause cells to grow out of control which leads to cancer.
Pharmacogenetics: The study of how single gene information or variations among a group of individuals affects drug response.
Pharmacogenomics: The study of pharmacology (the science of drugs) and genomics (the study of genes and their functions) to identify variants that together, will determine variability in drug response.
Phenotype: The observable characteristics of an individual that are determined by the genetic expression of a genotype and the environment.
Recessive Alleles: An allele that leads to expression of a trait only when paired with another recessive allele. It will be masked if a dominant allele is present.
Red Flags: Genetic red flags are features of personal and family medical history which suggest a higher than average chance of the presence of a genetic condition.
Sex Chromosomes: Identified as X and Y chromosomes in humans and most mammals, which determine the sex-linked characteristics of an organism. Females have two X chromosomes in their cells, while males have both X and Y chromosomes in their cells. The combination of these chromosomes gives an organism their different sex characteristics.
Single Gene Inheritance: A pattern of genetic inheritance in which a specific trait is determined by the expression of a single gene pair alone, which consists of two alleles. The offspring inherits one paternal allele, and one maternal allele.
Somatic Cell: Any cell of a living organism other than the reproductive germ cells such as the sperm and egg.
Somatic Variation: Genetic alterations that occur in the cells of an organism’s body often due to environmental factors or random errors in DNA replication. Somatic variations are only present in certain cells, and they do not affect the entire organism. Note that a large portion of an organism’s cells may contain the variation if the alteration occurs early on in development.
Sporadic Cancer: Cancer that occurs in individuals who do not have any family history of cancer or an inherited gene(s) which increases their risk of cancer.
Telomeres: A sequence of repetitive nucleotides at each end of a chromosome. They mainly protect the ends of the chromosomes from weakening or from fusing with other neighboring chromosomes.
Tumor Suppressor Genes: These genes normally function to slow down cell division, repair any DNA impairments, or tell damaged cells to induce apoptosis. When tumor suppressor genes are altered, cells may grow out of control, which can lead to cancer.
Variations: Permanent alterations in the DNA sequence which can be due to environmental factors or changes during the cell division process.
X-linked Inheritance: A pattern of genetic inheritance in which a variation occurs in the sex-linked chromosomes. One altered X chromosome is sufficient to cause the disorder in males since they only have one X chromosome. In females (who have two X chromosomes), the alterations would have to occur in both chromosomes in order for them to inherit the disorder.