BIO 315 Genetics Exam 1 Hennigan McNeese

• Genetics


  •the branch of biology concerned with the study of heredity and variation•The study of the of the origin, transmission, and expression of genetic information.
• Theory of epigenesis


  Adult organisms develop over time from a fertilized egg
• Theory of preformation

  The fertilized egg contains a complete miniature adult
• The cell theory


  •All organisms are composed of basic structural units called cells •All cells came from a previously existing cell
• The Origin of Species

  1859: Charles Darwin's book explained how various species evolve over time and only those with advantages can survive and reproduce
• Descent with modification

  Existing species arose from other ancestral species
• Natural selection


  The mechanism for evolutionary change
• History of Genetics

  1860s-Darwin's work 1860s- Mendel's work Published. 1900s to 1940s-Chromosome theory of inheritance proposed. Transmission genetics evolved. 1900s-Mendel's work rediscovered, correlated with chromosome behavior in meiosis. 1940s to 1950s-DNA shown to carry genetic information. Watson-Crick model of DNA. 1950s to 1960s-Era of molecular genetics. Gene expression, regulation understood. 1970s to 1980s-Recombinant DNA technology developed. DNA cloning begins. 1990s to present-Genomics begins. Human Genome Project initiated. 2000s-Application of genomics begins.
• Chromosomal Theory of Inheritance

  • Inherited traits are controlled by genes residing on chromosomes transmitted through gametes, maintaining genetic continuity form generation to generation
• What is a chomosome?

  Chromosomes Can Contain Hundreds of Genes; Chromosomes in diploid cells exist in pairs Called homologous chromosomes (X)
• Meiosis

  cell division that produces reproductive cells; Chromosomes are copied and distributed-Resulting cells (gametes) receive only half the number of chromosomes [haploid (n)]
• Mitosis


  cell division that produces reproductive cells; Chromosomes are copied and distributed-The two resulting daughter cells each receive a diploid set (2n)
• Alleles

  Mutations produce these of a gene- The source of genetic variation
• Genotype

  The set of alleles for a given trait
• Phenotype


  Expression of the genotype-Produces an observable trait
• DNA is

  Antiparallel Double-stranded helix, Made of nucleotides
• Monomer is

  Nucleotide consisting of a sugar (deoxyribose) , Bonded to a phosphate, Also bonded to the bases adenine, cytosine, guanine, and thymine
• Nucleotides form A-T and G-C

  Complementary base pairing across the helix
• RNA is

  •It is usually single-stranded • It has uracil (U) in place of thymine (T)•The sugar in RNA nucleotides is ribose instead of deoxyribose
• The Central Dogma

  •DNA → RNA → Protein
• Codons

  •Triplet nucleotides present in mRNA •The genetic code
• Proteins

  -the end product of gene expression-equal to Enzymes-20 different amino acids & Numerous combinations of these 20
• Classical or forward genetics

  Identifying the genes that caused mutant phenotypes
• Reverse genetics


  DNA sequence of a particular gene of interest (GOI) is known, but its function is not
• Gene knockout


  Allows scientists to render genes nonfunctional to investigate the possible role of that gene
• Recombinant DNA technology


  The ability to transfer genes across species
• Genomics


  Studies the structure, function, and evolution of genes and genomes
• Proteomics

  Identifies a set of proteins present in cells under a given set of conditions; Studies their functions and interactions
• Bioinformatics


  Uses hardware and software for processing nucleotide and protein data
• CRISPR-Cas systems

  •CRISPR is an RNA molecule•Recognizes and binds to its corresponding DNA sequence•Cas is a nuclease•An enzyme that cleaves DNA at a specific site in a specific way.•Together a CRISPR-Cas system can be used to target specific DNA sequences (ie. genes) and edit them.
• Modern model organisms

  •Viruses: T phages and lambda phages•Bacteria: Escherichia coli•Yeast: Saccharomyces cerevisiae
• Society is faced with a host of sensitive genetics-related issues like?

  •Prenatal testing•Ownership of genes •Access to/safety of gene therapy
• Plasma Membrane


  •Surrounds all cells•Separates cell from external environment
• Glycocalyx and Cell Wall

  Function: biochemical identity at cell surface
• How is the plasma membrane, glycocalyx or cell wall tied to genetic function?

  Receptor Molecules
• Receptor Molecules

  •are found on the surface of cells•Recognition sites that transfer specific chemical signals across the cell membrane into the cell
• Cytoplasm


  the material or protoplasm within a living cell, excluding the nucleus.
• Cytosol:

  Colloidal material surrounding organelles
• Cytoskeleton


  is made of extensive system of tubules and filaments
• Microtubules:

  Made up of the protein tubulin