Dixon Cumulative Final Review Genetics Unit Lecture 1 Intro to Biology Fundamental Properties of Living Organisms Complex Organization Cells tissues organs organ systems etc Emergent properties are due to these arrangements and interactions as complexity increases Metabolism Regulation Involves the release or use of chemical energy to produce work Homeostasis Both external and internal stimuli Uses energy from metabolism to aid in growth development controlled by Response to the Environment Growth and Development genes Reproduction Evolution Sexual vs asexual Occurs over many generations by the reproductive success of organisms with heritable traits favorable in the current environment Relation to Properties in DNA Complex Organization sugar deoxyribose phosphate nitrogenous bases Regulation mistakes maintained by DNA polymerases during replication Reproduction replication Evolution Response to Environment unsuitable traits expressed are eventually suppressed Lecture 2 Mitosis the Cell Cycle Multiple Functions of Cell Division Ex Amoeba divides into two cells creating two new organisms Reproduction Growth development Tissue renewal Interphase accounts for approximately 90 of the cycle For embryonic growth Phases of the Cell Cycle G1 phase cell growth S phase continues to grow as it copies its chromosomes G2 phase grows more as it completes preparations for cell division Stages of Mitosis Mitosis cell division Prophase Chromatin fibers become more condensed Nucleoli disappear Chromosomes appear as two identical sister chromatids two copies of one chromosome jointed together at their centromeres and all along their arms by cohesions Prometaphase microtubules The mitotic spindle begins to form Composed of centrosomes and Centrosomes move away from each other elongate the microtubules Nuclear envelope fragments microtubules invade the area Chromosomes more condensed Each chromatid of the chromosome has a kinetochore specialized protein structure located at the centromeres to which a centrosome attaches Metaphase longest stage Centrosomes are at the opposite poles of the cell Chromosomes line up on the metaphase plate so that the centromeres is in the middle one chromatid is above the line and one is below Anaphase shortest stage Cohesion proteins are cleaved the two sister chromatids are pulled Each daughter chromosome begins moving toward opposite ends of the apart cell kinetochore tubules shorten fragments of the parent cell Two daughter nuclei form in the cell nuclear envelopes arise from the Nucleoli reappear chromosomes become less condensed Division of cytoplasm creates two daughter cells Cleavage furrow in animals pinches the cell in two Cytokinesis Telophase Lecture 10 Sexual Reproduction Chromosomes Exists as Homologous Pairs in Diploids genes controlling the same inherited characters One chromosome consists of sister chromatids Both chromosomes carry Diploid cells are somatic cells everything but gametes When sperm and egg with 23 chromosomes rather than 46 unite the Meiosis Produce Haploid Cells chromosome number remains 46 Otherwise the number would double in each generation 23 46 92 Lecture 11 Meiosis Haploid Cells n sperm eggs Unite to Form a Diploid Cell or Zygote How Meiosis Creates Haploid Cells From Diploid Parent Cells Homologous pairs of chromosomes replicate to form sister chromatids on Homologous chromosomes separate to create two haploid cells MEIOSIS I each chromosome INTERPHASE Specifically not sure if we need to know Prophase I is where crossing over occurs exchange of corresponding DNA segments in NONsister chromatids Metaphase I pairs of homologous pairs line up at metaphase plate Anaphase I Homologs separate Telophase I Cytokinesis two haploid cells with replicated chromosomes each with two sister chromatids one or both chromatids include regions of nonsister DNA The sister chromatids separate to produce FOUR haploid cells with single chromosomes MEIOSIS II Similar stages to Mitosis Because of crossing over the two sister chromatids of each chromosome are NOT genetically identical result genetically variable gametes Lecture 5 Meiosis Variation Through Random Segregation of Chromosomes Independent Assortment Each homologous pair of chromosomes is positioned independently of the The first meiotic division results in each pair sorting its maternal and paternal other pairs during metaphase I homologs into daughter cells independently of every other pair Variation Through Crossing Over Makes sure that each chromosome is not exclusively maternal or paternal in origin Each homolog is paired precisely at the same gene on another homolog Proteins exchange the corresponding segments of the two nonsister chromatids one maternal one paternal to create new combinations of alleles Lecture 12 Mendelian Genetics Law of Segregation Mendel s first law two alleles in a pair separate into different gametes during gamete formation Egg or sperm gets only one of the two alleles present in the somatic cells A or a Law of Independent Assortment Mendel s second law each pair of alleles separate independently of each other pair of alleles during gamete formation Only applies to allele pairs located on different chromosomes Mendelian inheritance will not change allele frequencies Lecture 13 More Mendelian Genetics During meiosis each allele that is separated from the pair is equally likely to end up in the gamete When paired with the other allele from the other parent cell this creates genetic variation Sum Product Rule of Probability Product Rule Finding the probability of two or more independent events occurring TOGETHER Multiply the probability of one event by the probability of the other Sum Rule Two coins landing heads up X probability Finding the probability that one event OR the other occurs Add the two probabilities together Probability of getting a heterozygote B from sperm b from egg is b from sperm B from egg is probability Lecture 14 Still More Mendelian Genetics Patterns of Inheritance with Incomplete Dominance homozygotes Both alleles are expressed to give an intermediate form between the Differs from codominance where BOTH alleles are present not intermediate Can result as long as one parent is dominant in that trait BB BB BB bb Patterns of Inheritance for a Dominant Trait BB Bb Bb Bb Bb bb Patterns of Inheritance for Recessive Trait Cannot have a parent with homozygous dominance parents must be Bb bb or bb bb Lecture 9 10 Human Genetics and Linkage Patterns of
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