DNA Replication and Sequencing

Mitochondrion

Organelle that releases energy from nutrients through two membranes and enzyme-studded inner membrane

Peroxisome

Sac containing enzymes that break down and detoxify various molecules

Vesicle

Membrane-bound sac that temporarily stores or transports substances

Purines

Adenine (A) and Guanine (G) that have two rings

Domains of life

Three basic types: Archaea and bacteria (unicellular prokaryotes) and Eukarya (includes both unicellular and multicellular eukaryotes)

Chromosomes

Consist of DNA and protein, unwound and in a nucleus when a cell is not dividing

Levels of Genetics

Molecular -> cells -> tissues/organs -> individuals -> families -> population

Translation

Process that uses the information in RNA to assemble amino acids into proteins

DNA Components

Phosphate, sugar, and a base (Adenine, Thymine, Cytosine, Guanine)

DNA Replication

Process where a new double helix is formed from the old one using free DNA bases, resulting in two daughter cells with identical copies of the genome

DNA

Molecule that can replicate itself and is accessible to manufacture proteins

Prenatal Development

Embryo (first 8 weeks) - rudiments of all body parts form; Fetus (from 9th week) - structures grow and specialize

Carbohydrate

Provides energy and contributes to cell structure

Protein

Has many diverse functions such as forming the contractile fibers of muscle cells, enabling blood to clot, and forming the bulk of connective tissues

Enzyme

Proteins that facilitate or catalyze biochemical reactions, especially important in metabolism

DNA replication

Process of producing identical DNA molecules from a single original DNA molecule

Gene pool

Genetic populations defined by their collections of alleles

Genome

Complete set of genetic information

Cell

Basic unit of life, contains two genomes

Exome

Part of the genome that encodes proteins

Genomics

Field that compares and analyzes the functions of many genes

Bioethics

Addresses issues and controversies that arise in applied medical technology and using genetic information

Nucleic acids (DNA and RNA)

Most important macromolecules to the study of genetics

Dihybrid cross plot

16 boxes with all possible combinations from both traits

Genes

Instructions to manufacture proteins, which determine inherited traits and are composed of DNA

Cystic Fibrosis

Illustrates how a missing or abnormal protein causes symptoms of an inherited disease (CFTR)

Complex Trait

Determined by one or more genes and environmental factors, the more factors, the harder to predict risk occurrence

Mendelian Trait

Trait caused predominantly by a single gene

Somatic cell

Cell with 23 pairs of chromosomes (22 pairs of autosomes and 1 pair of sex chromosomes)

Transcription

Process that copies the DNA information into RNA in a process called gene expression

Mutation

Change in a gene that can have an effect at the whole person level, can be positive, negative, or neutral

Phenotype

Visible trait, biochemical change, or effect on health that is expressed by alleles

Genotype

Underlying DNA instructions that determine the phenotype

Cell traits

Inherited traits, quirks, and illnesses that arise from the activities of cells

Haploid

Cell with one set of chromosomes (n), found in germ cells (sperm and egg)

Diploid

Cell with two sets of chromosomes (2n), found in somatic cells (body cells)

Lipids

Form the basis of some hormones, form membranes, provide insulation, and store energy

Golgi apparatus

Stacks of membrane-enclosed sacs where sugars are made and linked into starches or joined to lipids or proteins

Endoplasmic reticulum

Site of protein synthesis and folding, lipid synthesis, and membrane network; rough ER has ribosomes, smooth ER doesn't

Nucleus

Porous, double membrane sac containing DNA that separates DNA within the cell

Biological membranes

Composed of a double layer of phospholipids, transport molecules, and keep out toxins and pathogens

Cell Division and Death

New cells form as old ones die, growth, development, etc. require constant rates of Mitosis/cytokinesis for division of DNA, and Apoptosis for precise, genetically programmed cell death

Plasma membrane

Cell-to-cell communication, signal transduction, and cellular adhesion

Cytoskeleton

Serves as the cell's architecture, positioning organelles and providing shape; composed of hollow microtubules, solid microfilaments, and intermediate filaments

Interphase

Resting phase that prepares for cell division, composed of G1, S, and G2 phases; chromosomes are uncondensed and replicated during S phase

IPMAT

Interphase - replication, prophase - spindle assembles, metaphase - chromosomes align, anaphase - centromeres part, telephase - spindle disassembles, and cytokinesis - organelles and macromolecules are distributed between two daughter cells

Control of the Cell Cycle

Groups of interacting proteins function at specific checkpoints, ensuring that chromosomes are correctly replicated and portioned in daughter cells

Telomere

Located at the end of chromosomes, contains TTAGGC sequences, and shortens after each cell division

Necrosis

Death of most or all of the cells in an organ or tissue due to disease, injury, or failure of the blood supply

Hormones and Growth factors

Hormones made in a gland and transported in the bloodstream, growth factors act locally for things like repairing scabs

Apoptosis

Programmed cell death that begins when a death receptor on the plasma membrane receives a signal to die

Stem cell

Divides by mitosis, producing two daughter cells or a stem cell and progenitor cell, which don't have the capacity of self-renewal

Biological sex

Made up of genetics, gonads, hormone levels, and genitals

Human development

First cell forms when a sperm and an oocyte join, reproductive systems have gonads, tubular structures, hormones, and secretions that control reproduction

Stem cell sources

Embryonic stem cells, induced pluripotent stem cells, and adult stem cells

Lysosome

Sac containing digestive enzymes that degrade debris and recycle cell contents

Microbiome

Symbiotic relationship between an individual's genome, diet, lifestyle factors, and the many microbes in the body

Exome sequencing

Process of determining the order of DNA bases in the genome that encode proteins, valuable for identifying extremely rare diseases swiftly

Metagenomics

Field that involves sequencing all of the DNA in a habitat

Ribosome

Scaffold and catalyst for protein synthesis, composed of two associated globular subunits of RNA and protein

The female Reproductive System

Oocytes mature in ovaries, released into uterine tube, and if fertilized, goes to uterus to divide and develop

Meiosis

Consists of two divisions, provides genetic diversity, and produces haploid gametes and diploid somatic cells

Mitosis v meiosis

Mitosis has one division, produces genetically identical daughter cells, and occurs throughout life cycle in somatic cells; Meiosis has two divisions, produces genetically different daughter cells, and is used for sexual reproduction

Gametes

Mature males begin making sperm at puberty and continue throughout life, females begin when they're a fetus and complete only if sperm fertilizes oocyte

Spermatogenesis

Process of sperm production, begins with spermatogonium dividing by mitosis, followed by meiosis 1 and meiosis 2

The Male Reproductive System

Sperm cells made in testes, stored in epididymis, and exit through urethra

Oogenesis

Process of egg cell production, begins with oogonium and involves meiosis 1 and meiosis 2

Fertilization

Union of sperm and oocyte, resulting in the merging of genetic packages and the formation of a zygote

Paternal Age effect

Arises from stem cells in the testes that divide every 16 days, increasing the chances of DNA replication errors and genetic mutations

Cleavage

Period of frequent cell division that occurs after fertilization, resulting in the formation of a blastocyst

Blastocyst

Structure formed from the hollowing out of a ball of cells, consisting of an inner cell mass and an outer trophoblast

Supportive Structures

Structures that support and protect the embryo, such as chorionic villi and the placenta

Embryo formation

Formation of the three primary germ layers (ectoderm, mesoderm, and endoderm) and the development of organs

Multiple Births

Arise early in development, can be dizygotic (fraternal) or monozygotic (identical), and can have different uterine environments

The embryo develops

Organogenesis transforms the three germ layers into distinct organs, and by week 8, all organs have begun to develop

Fetal growth

Growth and development of the fetus, including the development of hair, lashes, nails, vocal cords, and brain cells

Birth defects

Developmental abnormalities that occur during critical periods and can be caused by genetic or environmental factors

Teratogens

Chemical or other agents that cause birth defects, such as cocaine, cigarettes, alcohol, thalidomide, and viral infections

Maturation and aging

Human body becomes functionally less efficient with age, many diseases associated with aging have genetic components

Adult-onset inherited disorders

Single-gene disorders that predominantly affect health in early to middle adulthood

Syndromes that resemble accelerating aging

Single-gene disorders that speed up aging-associated changes, usually caused by the inability of cells to adequately repair DNA

Is longevity inherited?

Gene variants and shared environmental influences contribute to longevity

Monogenetic diseases

Diseases caused by mutations in a single gene, which are rare but affect a significant number of people

Modes of inheritance in single gene diseases

Autosomal dominant and autosomal recessive patterns of inheritance

Mendel's experiments

Experiments on traits in plants that led to the discovery of units of inheritance and how they pass through generations

Monohybrid Cross

Cross-breeding experiment that follows one trait and reveals the inheritance pattern

Characteristics of a Single-Gene Disease

Probability of recurrence, inheritance patterns, and the ability to predict risk

Mendel's laws

Law of segregation and law of independent assortment

Chromatid

Single, very long DNA molecule and associated proteins, forming a half of a replicated chromosome

Lethal Alleles

Alleles that cause death before an individual can reproduce

Multiple Alleles

Multiple possible alleles for a gene, resulting in variations in the phenotype

Epistasis

One gene affects the expression of another gene

Incomplete dominance

Heterozygous phenotype is intermediate between those of the two homozygotes

Codominance

Heterozygous phenotype results from the expression of both alleles

Penetrance and expressivity

Degrees of expression of a single gene, penetrance refers to all-or-none expression, and expressivity refers to the severity or extent of the phenotype

Pleiotropy

One gene controls several functions or has more than one effect

Genetic heterogeneity

Different genes can produce identical phenotypes

Phenocopy

Trait that appears inherited but is caused by the environment

Factors that alter single-gene phenotypic Ratios

Mitochondrial disorders, mitochondrial DNA, and nuclear DNA

Mitochondrial disorders

Diseases caused by mutations in mitochondrial genes, which are inherited maternally