BIOB 375 1st EditionExam # 2 Study Guide Lectures: 13-22Lecture 13 (February 18)Cell Divisions- Living organisms are capable of growth and reproduction o Growth In size In numbero Reproduction Asexual reproduction Sexual reproduction In Bacteria:- Growtho Only size- Reproductiono Asexual reproductionIn Eukaryotes:- Growtho In sizeo In number – Through cell division (Mitosis)- Reproductiono Asexual reproduction – Mitosiso Sexual reproduction - MeiosisReproduction of eukaryoteSexual reproduction  MeiosisAsexual reproduction  MitosisSexual reproductionIn plants:- Anthers (male) part- Stigma (female) partSexual reproduction  seedsAsexual reproduction  potatoIn animals:Sexual reproduction  babyAsexual reproduction  cloning Somatic cells – normal cellsGametic cells – reproductive cellsThree fundamental events in cell division:- Growth- Receiving signal for dividing 1. Synthesize enzymes for DNA replication 2. DNA replication 3. Check for the accuracy of DNA replication - Damaged cell will degrade and healthy cell will go on to replicate and complete the cycleagain Lecture 14 (February 20)Three fundamental events in cell division:Copying of genetics material  Replication- In both mitosis and meiosis Equally dividing of genetics material- Mitosis and Meiosis 1&2Dividing of cell* Know which part of cell undertakes a type of cell division? What is the result?Mitosis- Happens in somatic cells: to increase cell number or to replace dead cells- G1SG2 ProphaseMetaphaseAnaphaseMeiosis- Created gametes for sexual reproduction- Meiosis also has interphase G1-S-G2- Meiosis 1  Chromosome number reduce in half, but amount of DNA molecules are thesame as another cell- Meiosis 2  Both chromosome number and DNA molecules reduce in half- Homologs chromosome  chromosomes that have same gene trait from each parent in same location on chromosome (ex. Hair color, or hand size)- Four daughter cells- Prophase 1  events don’t happen in MitosisMajor differences- Cell type- Chromosome number- VariationYou are expected to be able to:- Identify type of cell division and stages of cell divisionWhere are the cells that could be under mitosis?Where are the cells that could be under meiosis?- Stamen and Ovary of a plant- Ovary (Oogonia cell) and Testis (Spermatogonia cell) of a humanImportant:Mitosis- Type of cell  Somatic cells- Mitosis produces genetically identical cells- All the somatic cells of an individual have identical genetic materialMeiosis- Cell typeso Microsporocyteo Magasporocyteo Spermatogoniao Oogonia- Meiosis produces 4 different gametes with half of the chromosome number of the mother cells, enhances genetic variationLecture 15 (February 23)Genetics: is the science to study the mechanisms of heredity and variation in living organisms.Heredity or inheritance: the passing on of characteristics from one generationMitosis- Asexual reproduction- Produces genetically identical cells- Genotype is exactly the same * this concept on examo AABbCc  AABbCcMeiosis- Sexual reproduction- Produces 4 different types of gametes with half of the chromosome number of the mother cell- Enhances genetic variation- Sperm  AB, Ab, aB, ab- Egg  AB, Ab, aB, abAB Ab aB abAB AABB AABb AaBB AaBaAb AABb AAbb AaBb AabbaB AaBB AaBb aaBB aaBbab AaBb Aabb aaBb aabb- Their children could be: AaBb, AABB, AABb, AAbb, AaBB, Aabb, aaBB, aaBb, aabb- They all have a gene from either the father or the motherVariation arises from mutation- Genetic materialo DNA  for most living organismso RNA  for some living organisms- A mutation is defined as an inherited change in genetic information o Changes in the DNA sequence of the living organisms that DNA is the genetic informationo Changes in the RNA sequence of the living organisms that RNA is the genetic material - Mutation is the source of all genetic variationConsequences of mutations- The sustainer of lifeo Ability to adapt to environmental changes- The cause of great sufferingo Most mutations have detrimental effectso Diseases and disorderso Death Causes of mutation- Spontaneous mutations- Induced mutationsErrors during replication- Replication is highly accurate: less than one error in a billion nucleotides - Three processes to ensure the accuracy of replicationo Nucleotide selectiono Proofreadingo Mismatch repair- Causes of replication errorso Tautomeric shif Purine and pyrimidine bases exist in different chemical forms called tautomers. The standard base pairs occur between the common forms. But if a base is in its rare form, other base pairing is possible Common base pairing: A-T, C-G Rare base pairing: C-A, T-GCauses of mutation- Chemical changes in genetic materialso Depurination  In mammalian cell cultureo Deamination- Chemical induced changes in genetic materialso Base analogsSpontaneous mutations are RARENot all changes in DNA change phenotype- Why not?o The nucleotides can change, but the coding for amino acids stays the sameMost of mutations have detrimental effectsPrevent mutations in our DNA as much as possibleInduce mutations when we need them:- Chemicals- RadiationsCategories of mutations- Somatic mutations  not pass through generation- Germ-line mutation  pass through generation o Germ-line tissue = gametic cellsTypes of gene mutations- Base substitutiono One codon changed- Base insertion- Base deletionBase substitution – Cause single nucleotide polymorphism (SNP)- Transitions – more frequent- TransversionsInsertions/Deletions (Indels)- In-frame Indels: insert or delete multiple of three nucleotideso Change a few amino acids- Frameshif Indels: insert or delete non-multiple of three nucleotidesAffects the entire protein sequence afer the IndelLecture 17 (February 27)Chapter 16 - Variations arise from chromosome reassortment II- How to predict variations when two gene loci are taken into consideration Concept of the Principle of Independent Assortment (Mendel’s Second Law)- The law states that alleles at different loci of different chromosomes separate independently of one anotherGenotypes of the gametesMendels Principles (Key Points):- Two alleles at a locus segregate- Dominant is observed when two alleles are different- The separation of two alleles at one locus is independent of the separation of alleles at other loci9 different genotypes (because some repeat from the 16)Ratio is 9:3:3:1Lecture 18 (March 2)Variations arise from chromosome