Bio Unit 3 PDF

Unit 3: The Cell Cycle: - - The roles of nucleic acids: Two types: - - - The components of Nucelic Acid: - - - There are two families of nitrogenous bases: - - - DNA vs RNA: - - Nucleotide Polymers: - - - - The structure of DNA and RNA molecules:...

Unit 3: The Cell Cycle: - - The roles of nucleic acids: Two types: - - - The components of Nucelic Acid: - - - There are two families of nitrogenous bases: - - - DNA vs RNA: - - Nucleotide Polymers: - - - - The structure of DNA and RNA molecules: - - - - - Somatic cells vs Gamete cells: - - Cell Divison: - - - - - Cell Cycle summary: - - - Phases of Mitosis: Mitosis is conventionally divided into five phases: - - - - - - Phases of the cell cycle: The cell consists of: - - The Mitotic Spindle: - - - - - - - - - - - - Cytokinesis: - - Binary Fission in Bacteria: - - - - Comparison of Asexual and Sexual Reproduction: - - - - Sets of chromosomes in human cells: - - - - - - - - - - - - - - - - - - - The behavior of Chromosome sets in the human life cycle: - - - - - - - The variety of sexual life cycles: - - - The Human Life Cycle: - - Three types of sexual life cycles: - - - Haploid dominant: - - - - Alternation of generations: - - - - - - - - - How meiosis reduces chromosome number: - The stages of Meiosis: Meiosis 1: - - - - - Meiosis 2: - - - - Meiosis 2 is very similar to mitosis. The only real difference is that the cells are haploid at the start The big, important differences between meiosis 2 and mitosis: - Crossing over and synapsis during prophase 1: - - - - Genetic variation produced in sexual life cycles contributes to evolution: - - - Origins of genetic variation among offspring:\ The behavior of chromosomes during meiosis and fertilization is responsible for most of the variation that arises in each generation Three mechanisms contribute to genetic variation: - - - The evolutionary significance of genetic variation within populations: - - Cellular organization of the genetic material: - - - Drawing the deck of genes: - - - Mendel's experimental, Quantitative approach: Mendel probably chose to work with peas because: - - - - - - The law of segregation: - - - - - Mendel's model: - - - - - - - - - - Genetic vocabulary: - - - - - Rules of probability: - - - Inheritance patterns are often more complex than predicted by simple Mendelian genetics: - - **Genetics Glossary:** **Complete dominance: one allele hides the other where present** **Incomplete dominance: heterozygotes are between homozygotes on a spectrum** **Codominance: 2 dominant alleles affect alleles affect phenotype in different ways** **Multiple alleles: more than 2 alleles for a given gene** **Pieiotropy: alleles have more than one phenotype** **Polygenic: more than one gene gives a phenotype** **Epistasis: where one gene affects another\'s action in the generation of a phenotype** Nature and nurture: environmental impact on phenotype: - - By convention: - - - - - Recessively inherited disorders: - - The behavior of recessive alleles: - - - Pedigree: - - - - - - Treatments for genetic diseases: - - Cystic Fibrosis: Sickle-Cell Disease The chromosomal basis of Mendel\'s laws: Mitosis and Meiosis were first described in the late 1800s The chromosome theory of inheritance states: - - The behavior of chromosomes during meiosis can account for Mendel's laws of segregation and independent assortment Morgan's choice of experimental organism: - - - The chromosomal basis of sex: - - - - - - - - - - Inheritance of X-linked Genes: X-linked genes follow specific patterns of inheritance: For a recessive X-linked trait to be expressed: - - Some disorders: - - X inactivation in female mammals: - - - - - Locating genes along chromosomes: - - Sex-linked punnett squares: - - Alterations of chromosome number or structure cause some genetic disorders - - 1. 2. Abnormal chromosome number: - - - - - - - Polyploidy is common in plants but not in animals Spontaneous origin of polyploid individuals plays an important role in the evolution of plants Alterations of chromosome structure:\ Breakage of a chromosome can lead to four types of changes in chromosome structure: - - - - - - Human disorders due to chromosomal alterations: - - - Down syndrome: - - - - Aneuploidy of sex chromosomes: - - - Disorders caused by structurally altered chromosomes: - - - Causes: - - -