Asexual Reproduction Only one parent required Genetically identical offspring created Uses MITOSIS to make clone organisms No gametes used
Types of AsexualReproduction• Budding Used by yeast and hydra• Vegetative Used by plants• Binary Fission Used by bacteria QUESTION: Which type of asexual reproduction is shown to the right???
Sexual Reproduction• Gametes are produced by the process of meiosis – Crossing-Over of Meiosis I ensures genetic variation between offspring – Gametes are HAPLOID cells (N)• Egg and sperm unit to form a zygote – Zygote is the first DIPLOID cell (2N) of a new individual. The zygote becomes a fully-formed individual through mitosis
If a somatic cell has 100chromosomes. . .• Cells undergoing • Cells undergoing MITOSIS will have MEIOSIS will have 50 100 chromosomes chromosomes each each • HAPLOID cells• DIPLOID cells created created
Genetics ReviewGenotypes Phenotypes• Two alleles for an • Physical autosomal trait characteristics• HH – homozygous dominant • Hh and HH create the• Hh – heterozygous same phenotype• Hh – homozygous recessive
Punnett Squares for AutosomalTraits • What percentage of children will have the dominant phenotype? • What percentage of children will have the recessive phenotype?
Sex-Linked Traits• Carried on X- • Boys receive X- chromosome chromosome and its alleles from MOM• Recessive alleles cause disorders like • Use a SPECIAL colorblindness, Punnett Square to hemophilia, and predict baldness
Sex-Linked Punnett Squares• What percent of males inherit the disorder?• What percent of females are carriers for the disorder?
Pedigrees • Study the pedigree to the right. • What kind of trait is shown? Explain. . .
DNA and RNA• DNA is double- • RNA is single- stranded stranded• Base pair rules: • Makes a single-strand – A—T copy off an open DNA – C—G strand• For ATT-CGA: what is • For ATT-CGA: what is the complementary the complementary DNA strand? RNA strand?
Functions• DNA: contains thousands • RNA: of genes written as nucleotide sequences mRNA: carries gene information from nucleus to ribosome• Genetic code determined rRNA (ribosome): site where mRNA instructions are read by DNA nitrogen base tRNA: carries amino acid to sequence ribosomes according to mRNA instructions• Kept in the nucleus of eukaryotic cells
Steps of Protein SynthesisTRANSCRIPTION:• DNA gene opens to attach mRNA nucleotides• mRNA copies DNA gene in the nucleus• DNA closes back up as mRNA exitsTRANSLATION:• mRNA attaches to a ribosome where tRNA brings correct amino acids
Two Important Types ofGene TechnologyGene splicing Genetic Engineering• Genes from an organism • Used to replace undesired are removed and inserted genes of an organism with into another organism better onesExample: inserting human Example: Glow in the dark insulin-producing gene in puppies are created by bacteria to produce insulin inserting the glowing gene quickly and economically from jellyfish into the dog DNA
Gel Electrophoresis• Used to determine relatedness of organisms• Separates DNA bands by size• Shorter segments travel the furthest through the matrix