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Unit 6: Chapters 23, 24, & 25: Genetics Basic Genetics Modern Genetics Understanding our genes and the ways they are passed to the next generation.
A. Basic Genetics _________ = study of heredity understanding of how _______ get ____ from __________, ___________ 1. Traits = characteristics hair color, eye color, widows peak, tongue rolling, ear lobes
2. Gene Chromosome Theory - ____________________ found in the nucleus - Because of ___________ (2 of each chromosome) _______________ called ___________
- Remember that through meiosis each parent only passes on _____________ - Through fertilization the __________ of genes is restored - Organisms can have __________ the _________ of the organism
3. ________________________ When __________________ there is a __________________ on homologous chromosomes. _______________________. As a consequence, _____________ are likely to be produced. 4. _________________________________________________ (nonhomologous chromosomes), they ________________ and, therefore, may be _______________ of each other. (not linked) 5. _____________________________________. The _________________________.
6. Probability and Inheritance a) _______ = genetic make up / ______ of an individual _______ = same alleles (TT or tt) _______ = different alleles (Tt) = Hybrid b) ______ = __________ (Tall or Short) Usually ____________ – sometimes the _______ can affect the phenotype. Can two organisms have the same phenotype but different genotypes?
c) Punnett Square representation of ___________ and the different ___________________ ex: Cross: Homozygous Tall x Homozygous Short 1. Determine the genotypes of the parents 2. Determines the possible gametes of the parents 3. Write the gametes on the outside of the box 4. Combine the parents gametes Remember only 1 gamete from each parents All the offspring are genotype Tt – heterozygous The genotype tells the phenotype – Tt Tall In the heterozygous the recessive allele is hidden
ex: Cross: Heterozygous Tall x Heterozygous Tall What is the genotype ratio? What is the phenotype ratio? Through his knowledge of math and detailed record keeping, with 10, 000 s of pea plants Gregor Mendel always had this ratio in the phenotypes.
B. Human Inheritance a) ________ - a diagram of family relationships that uses symbols to represent people and lines to represent genetic relationships. - easier to visualize relationships within families - Pedigrees are often used to determine the mode of inheritance (dominant, recessive, etc. ) of genetic diseases.
b) Human Genetic Diseases / Disorders 1) ________ recessive allele lack pigment in skin, hair, eyes 2) ________ recessive allele excess mucus in lungs; increases susceptibility to infections; death in childhood unless treated 3) __________ recessive allele accumulation of phenylalanine (amino acid) in tissue body can not break down the amino acid mental retardation if they eat phenylalanine
4) _________ recessive allele higher occurrence (1/100 vs 1/100, 000) in Jewish families of eastern European ancestry lipid accumulation in brain cells, nervous system break down death in early childhood 5) ___________ dominant allele bones fuse and stop growth
6) ___________ codominant allele red blood cells have a crescent shape misshapen hemoglobin can not carry O 2 as well 7) __________ dominant allele extra toes and fingers not always expressed 8) ___________ chromosomal disorder extra 21 st chromosome cause by nondisjunction
C. Modern Genetics 1. ___________ – 1950’s Used Rosalind Franklin’s x-ray pattern of DNA to build its 3 -D structure Double helix with complimentary base pairs a) DNA Structure _________ A = ________ B = ________ C = ________ A–T G–C _____________ From the human to the DNA – PBS Flash
DNA STRUCTURE MOVIE
2. DNA Replication a) Occurs inside the _________ b) DNA molecules __________, then produces ________________________ c) Each original strand serves as a template for the new strand
Original DNA “Unzips” Enzymes fill in nucleotides TAC ATG CGG GCC ACC TGG CGT GCA AGG TCC CAA GTT TAG ATC TAC CGG ACC CGT AGG CAA TAG
Easy Version of DNA Replication Check out this site on your own for a more detailed explantation More Complicated but explains the process really well. http: //207. 4. 198/pub/flash/24/menu. swf
3. Protein Synthesis a) RNA = __________ nucleic acid contains Ribose as the sugar not _____ as in DNA has the base ____ instead of _____ as in DNA Types of RNA ______ = _______ carries gene out of the nucleus r. RNA = ribosomal RNA makes up ribosome ______ = _______ brings in amino acid
b) Transcription 1 st step of protein synthesis; similar to replication _____________ Occurs in the _______ “Unzip” DNA – uses 1 side of DNA as a template RNA polymerase fills in complimentary RNA bases m. RNA detaches from DNA m. RNA leaves nucleus Simple Trasncription Animation Just another Trancription animation
Original. Enzymes fill in RNA nucleotides DNA “Unzips” RNADNA reconnects breaks from DNA TAC CGG ACC CGT AGG CAA TAG ATG AUG GCC TGG UGG GCA TCC UCC GTT GUU ATC AUC The groups of 3 bases on the m. RNA is called a CODON The codon codes for specific amino acids when making a protein
c) Translation 2 nd step of protein synthesis _____________________ occurs in the _______ at the __________________________ Matches the ________________ reads next _____ and brings in next t. RNA with matching anticodon Since _____ is attached to ____ – two amino acids are located next to each other This proximity allows the ________ Makes a _______ Repeats until m. RNA says stop
More than 1 ribosome can attach to the m. RNA at a time Makes multiple peptides Translation Animation
d) Protein Synthesis Overview To see it in some more detail check out the following website on protein synthesis http: //learn. genetics. utah. edu/content/begin/dna/ e) Genes code for peptides generally a protein is the combination of more than 1 peptide Try this website as an interactive for replication and protein synthesis http: //www. pbs. org/wgbh/aso/tryit/dna /shockwave. html
4. Mutations Changes in the DNA sequence Some are good Some are bad Most are neutral Mutations are only passed to the next generation if they occur in gametes Mutations in somatic cells are not passed – acquired characteristics are not passed
a) Gene Mutations changes in a single gene 1) Point Mutations – involve just one nucleotide substitution = change one nucleotide for another ex: TAC GCG ACC CGA becomes TAC GCC ACC CGA the change may or may not change the amino acid
2) Frameshift Mutations insertion or deletion of a single nucleotide changes the codons read by the ribosome usually affects all amino acids after the mutation ex: DNA: TAC CGG ACC CGA m. RNA: AUG GCC UGG GCU Amino A: Met Ala Try Cys Insertion DNA: TAC GCG GAC CCG m. RNA: AUG CGC CUG GGC Amino A: Met Arg Leu Gly A U The order of amino acids changed changes protein (big time)
Ex: delete 1 letter THE FAT CAT ATE THE RAT THE FTC ATA TET HER AT ? ? Completely change everything after the deletion No longer makes sense The same thing happens with the protein The order of the letter (amino acids) determines the structure of the words and sentence (protein) One little mistake can completely change the meaning
b) Chromosomal Mutations changes the structure of a chromosome rearrange the genes on a chromosome 1) ____________ 2) ____________ 3) ____________ 4) ____________ Chromosomal Mutations
c) Mutagenic Agents factors that cause mutations 1) __________ – X-rays _________ radioactive substances, and cosmic rays 2) _______ – formaldehyde, benzene, asbestos fibers _______________
D. DNA Technology ways in which the knowledge of DNA can help benefit society a) _____________ in organisms, mating the organisms, and hoping some of the offspring have the combinations of the traits ex: dogs, cattle, crops selective breeding has been occurring for 1000 s of years
b) _______________; transfer DNA from one organism to another isolate gene _____________________________ place recombinant DNA in a new organism *restriction enzymes = cut DNA at very specific sequences
can be used to make a variety of products
c) ________ making an ________ Remove the nucleus of an egg cell Use the nucleus of a body cell Insert the nucleus into the egg cell Grow the egg cell Identical genetic copy of the body cell organism Click and Clone
d) ____________ making “_________” use restriction enzyme to cut DNA into fragments place DNA into a porous gel electrify gel and DNA fragments move small pieces move the farthest Gel Electrophoresis - Learning Center Gel Electrophoresis Virtual Lab
e) Human Genome Project sequence all human DNA map and locate all the human genes about 3, 000, 000 base pairs in order help to find and cure diseases Gene Therapy find defective gene and replace it with a healthy gene