ZOL 141 1st Edition Exam 1 Study Guide Lectures 1 11 Lecture 1 January 14 Introduction to Human Genetics and Overview of its history What is Human Genetics Describe the Human Genome Ethical Concerns of Hereditarianism Definition of human genetics The study of inheritance as it occurs in human beings Human Genome o 3 2 billion base pairs o 3 codes for genes the rest is junk o 19 000 genes o we are 99 9 identical to our neighbor Why is Hereditarianism wrong o Most human traits are dependent on many genes and the environment o Everyone has 5 10 hidden deleterious alleles if someone has two of the same they cannot live o How do you decide which traits are desirable o breeding humans is simply unethical Lecture 2 January 16 Genes and Genome Macromolecules What is a trait gene DNA Genome What is a macromolecule Name different kinds Three key properties of DNA What s important about Nucleic acids What is a trait o An observable property of an organism What is a gene o The fundamental unit of heredity o Basic structural and functional unit of genetics What is DNA o Deoxyribonucleic acid o Helical molecule consisting of two strands of nucleotides o Carrier of genetic info What is a Genome o Set of DNA sequences carried by an individual o Biggest genome 132 8 billion bp Macromolecules Large cellular polymers assembled by chemically linking monomers together Include carbohydrates lipids proteins nucleic acids DNA 1 Needs to store genetic info stored in sequence A C G T nucleotides Almost infinite combinations 2 Needs to be self replicating Structure must allow faithful replication 3 Needs to be able to mutate Mutations caused by changing bases Nucleic Acids Bases DNA Adenine Thymine Guanine Cytosine RNA Adenine Uracil Guanine Cytosine Base pairing specific o A T 2 hydrogen bonds o C G 3 hydrogen bonds o Chargaff Rules Purines must pyrimidines A T G C Lecture 3 January 21 DNA Replication What are the leading and lagging strands How are DNA organized in chromosomes What are the DNA replication enzymes Leading lagging leading strand synthesized continually lagging strand synthesized discontinually DNA organization Chromatin DNA and protein components of chromosomes Total length of DNA in one cell 2 meters 6 5 feet Needs to fit into nucleus tight packing Wraps around histones DNA replication enzymes Helicase and DNA polymerase Helicase unzipping enzyme opens up DNA breaks hydrogen bonds DNA polymerase puts in correct nucleotides Lecture 4 January 23 The Cell and its Organelles What is a cell Describe some organelles The Cell Basic Unit of structure and function in ALL organisms o Humans 100 trillion cells Cells differ in their size shape function and life cycle o Giant squid has 39 foot nerve cells o Ostrich egg yolk 3 lbs biggest cell At structural level they are all similar o Cell has different substructures o Organelles cytoplasmic structures that have specialized functions o Function of a cell is under genetic control Organelles o o o o o o Nucleus Nuclear envelope nucleolus chromatin nuclear pore Endoplasmic reticulum rough ribosomes associated protein synthesis occurs and smooth lipids and steroids made Golgi complex Lysosome garbage can unwanted things deposited here Mitochondrion ATP production contains own DNA up to 1000 per cell involved in muscle movement Centrioles important for structure mitosis Lecture 5 January 26 The Cell Cycle Definition of Cell cycle How many stages What is the purpose of Mitosis What are the phases of mitosis Cell cycle Definition sequence from one cell division to the next cell division Three stages 1 Interphase G1 S G2 2 Mitosis produces two genetically identical daughter cells i e nuclear division a Telophase b Anaphase c Metaphase d prophase 3 Cytokinesis cytoplasmic cell division Mitosis Form of cell division that produces two genetically identical cells Chromosomes have already replicated Early prophase two pairs of centrioles nuclear envelope begins to break down nuclear envelope starts to open up Late prophase chromosomes condense even more centrioles migrate to top and bottom of cell Transition to Metaphase no nucleus DNA dispersed throughout cell spindle fibers begin to attach to centrioles with microtubules Metaphase chromosomes line up in middle of cell equator each chromosome connected to centriole Anaphase movement of chromosomes toward different poles each chromatid separated sister chromatids move to opposite poles ensures that two daughter cells are genetically identical Telophase Nucleus begins to form again in each daughter cell still connected Cytokinesis Daughter cells completely divide from each other Mitosis is Essential for Growth Lecture 6 January 28 Review of Mitosis Phases Intro to Meiosis What occurs in each of the four stages of mitosis What does it mean to be diploid vs haploid Mitosis Prophase Chromosomes condense Chromosomes randomly located in nucleus Metaphase Chromosomes align at equator Anaphase Sister chromatids break apart and move to opposite poles of cell Telophase and Cytokinesis Two daughter cells with two chromosomes each stick form Diploid haploid Diploid 2n somatic cells o Somatic normal human cell o 46 chromosomes OR 23 pairs o diploid 2n o two chromosome sets one from mom one from dad o each chromosome is represented twice as a member of homologous pair homologous chromosomes have identical loci one from dad one from mom Haploid n gametes o i e egg or sperm 23 chromosomes no pairs o Haploid n o One chromosome set o Each chromosome represented once o N 2 Lecture 7 January 30 Meiosis 1 and 2 What occurs in Meiosis 1 and 2 What are the phases involved What is the end result of meiosis Meiosis 1 reduces chromosome number to haploid Meiosis 2 separates sister chromatids Meiosis 1 o Prophase 1 metaphase 1 anaphase 1 telophase 1 o Cell Diploid 2n 4 chromosomes Haploid n 2 chromosomes o Prophase 1 start with replicated chromosomes two sister chromatids Similar to mitosis in that nuclear envelope begins to disintegrate Different from mitosis in that chromosomes begin to pair up Crossing over chromosomes physically exchange parts o Metaphase 1 Pair of homologous chromosomes line up at equator o Anaphase 1 Paired homologous chromosomes separate homologous chromosomes pulled to opposite ends of cell o Telophase Cells start to separate o Up until anaphase 1 the cells are diploid four chromosomes with two chromatids each Meiosis 2 o Prophase 2 same as mitosis o Metaphase 2 All chromosomes lined up on one plane o Anaphase 2