I.Genetics A. Mendel father of genetics Inheritance traits
carried on chromosomes Genes code for certain traits Alleles same
gene, different trait
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B. Principle of dominance dominant trait will express itself
1.Dominant traits expresses, shows up 2.Recessive traits will only
show up if both recessive alleles are present
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C. Genotype gene, code R = red & r = white 1. Homozygous
dominant 2 dominant alleles (RR = purebred) 2. Homozygous recessive
2 recessive alleles (rr = purebred) 3. Heterozygous one dominant
and one recessive allele (Rr = hybrid) D. Phenotype how genotype
expresses itself, looks like
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C.Punnett square prediction of pairing R = red, r = white
Genotypes all Rr Phenotypes all red RR x rrR Rr Rr Rr r r R = red,
r = white Genotypes 1 RR, 2 Rr, 1 rr Phenotypes 3 red, 1 white Rr x
Rr RR Rr rr R r RrRr Heterozygous(hybrid) cross
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D.Incomplete dominance heterozygous blending of dominant and
recessive trait Genotypes all Rr phenotypes all pink RR x rr 1RR =
red, 2Rr = pink, 1 rr = white 2 pink and 2 white Rr R r RRRr rr R r
RrRr rr Rrrr R r r
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E.Codominance if heterozygous, both traits are expressed Blood
types : antigens A, B, AB, O AB blood - both A and B antigens are
present Positive blood is a separate gene Rh d antigen
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F.Multiple alleles traits expressed on more than two alleles
1.3 or more alleles combinations of alleles genotype AABBCCDD whats
the phenotype 2.Human examples Hair color 3 alleles (9) Eye color 3
alleles (9) Skin color 8 alleles (64)
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G.Polygenic system interaction of multiple genes, determines
phenotype 1.Continuous variation full range of phenotypes
2.Discontinuous variation phenotype fall into a few well separated
categories
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H. Environmental Influence on gene expression 1. sun exposure,
cold example: siamese cat and himalayan darker color on ears, face
and paws
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I. Principle of segregation 1.Gametes separation of alleles
occurs during meiosis 2.Parental purebreds homozygous, dominant or
recessive (RR x RR or rr x rr) P generation = RR x rr 3.First
filial F1 generation, offspring of P generation, hybrids
heterozygous Rr 4.Second filial F2 offspring of hybrid cross,
phenotype ratio 3:1
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J. Independent assortment Dihybrid cross TtGg x TtGg predicted
phenotypes 9:3:3:1 T = tall t = dwarffill this in G = green g =
albino
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Punnett Square for BbEe sire bred to BbEe dam * Dam can
contribute BEbEBebe Sire can contribute BEBBEEBbEEBBEeBbEe
bEBbEEbbEEBbEebbEe BeBBEeBbEeBBeeBbee beBbEebbEeBbeebbee Being
black, sire and dam must both be B-E-; having produced yellow and
chocolate pups, each must also have the b and e alleles, so in each
case the genotype is BbEe. A BbEe parent can contribute the four
combinations of alleles BE, bE, Be, and be to various pups.
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BBEE (1 pup in sixteen or 6.25%) black BbEE (2/16 or 12.5%)
black BBEe (2/16 or 12.5%) black BbEe (4/16 or 25%) black bbEE
(1/16 or 6.25%) chocolate bbEe (2/16 or 12.5%) chocolate BBee (1/16
or 6.25%) yellow Bbee (2/16 or 12.5%) yellow bbee (1/16 or 6.25%)
yellow with brown nose and light eyes
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II. Human genetics A. Karyotyping human chromosomes 1.Autosomal
22 pairs of somatic 2.Sex chromosomes 1 pair XX or XY
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B.Pedigree genetic relationship in families
http://www.zerobio.com/drag_gr11/pedigree/pe digree1.htm
C.Abnormalities different from the norm D.Disease serious disorders
or abnormalities caused by genes
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III. Human genes A. Autosomal recessive inheritance must have
both recessive alleles 1.Albinism aa, cant make melanin 2.Tay-sachs
disease at 6 months develops spot on retina blindness, death
3.Cystic fibrosis most common 1/2500 children 4.Lactose intolerance
dont have lactase 5.Sickle cell anemia red blood cells, sickle
shaped so cant carry O 2 well and get stuck in capillaries
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B.Autosomal dominant inheritance two dominant alleles or
heterozygous 1.Darwin tubercle thickened rim of cartilage in ear
2.Achondroplasia dwarfism 3.Huntingtons disease manifests in 30s or
40s, loss of muscle control, loss of brain tissue 4.Polydactyly 6
fingers or toes
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IV. Sex-linked human inheritance traits carried on the x
chromosome A.Sex linked disorders XX normal female, X - X female
carrier, X - X - afflicted female, X - Y afflicted male, XY normal
male 1.Hemophilia bleeding disorder X - Y or X - X - 2.
Colorblindness red- green blue, X - Y or X - X -
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V. Incorrect chromosome number any number but 46 in humans
(Down syndrome- 47) trisomy on the 21 st chromosome A.Disjunction
abnormalities extra or too few, occurs in meiosis, can also result
in some degree of mental retardation and increased risk of diseases
and defects 1. Turners syndrome: XO 2. Klinefelter syndrome: XXY 3.
Meta or super female: XXX 4. Jacob syndrome: XYY
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VI. Gene Regulation in Eukaryotes Female cat cells inactivate
one of two X chromosomes in every cell (producing a Barr body)
Different patches of skin cells in a cat inactivate different X
chromosomes Patches of fur growing from skin cells may differ in
color if fur genes on X chromosomes differ
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VII. Structural abberrations A.Deletions part of chromosome is
missing, cri-du-chat syndrome #5, leukemia #21 B.Inversions part of
chromosome is reversed C.Translocation part of one chromosome
breaks off and attaches to another chromosome D.Duplications
chromosome replicates genetic material it already has VIII.Genetic
screening Ethical issues insurance
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I.Chemical nature of genes A.Coding capacity genes carry codes
produces traits in the organism B.Transformation A T G C Adenine
Thymine Guanine Cytosine nucleotide code for all traits II.DNA
deoxyribonucleic acid A.Base composition Chargaffs rule A T, T A, G
C, C - G B.Double helix model 1953 by Watson and Crick nucleotides
form rungs of ladder, phosphate and ribose (sides)
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1.Purines 2 carbon ring, adenine and guanine 2.Pyrimidines
single carbon ring, thymine and cytosine 3.Base pairing A T, G C
III.DNA replication A.Template bases need to form a complimentary
strand B.DNA polymerase enzyme which separates the base pairs
separates the DNA molecules IV.Mutations Alteration of the
bases
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I.RNA ribonucleic acid one strand A.Composition C G, A U,
cytosine, guanine, adenine, uracil B.Function carry DNA
instructions to various cell parts C.Protein synthesis code for
amino acid sequences
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D.Messenger RNA mRNA, carries DNA instructions codons E.
Transfer RNA tRNA, translate the code anticodons F. Ribosomal RNA
rRNA, from code puts amino acids together to form proteins G. RNAi-
interference RNA- destroys suspect codes such as viruses
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RNA Intermediaries There are three types of RNA involved in
protein synthesis Messenger RNA (mRNA) carries DNA gene information
to the ribosome Transfer RNA (tRNA) brings amino acids to the
ribosome Ribosomal RNA (rRNA) is part of the structure of
ribosomes
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II.Transcription mRNA carries the code DNA mRNAtRNAamino
acidrRNA C GCG assemble T AUA aspartic acid amino G CGC acids A TAU
make C GCG cysteine the G CGC protein (transcription) (translation)
(codons) anticodons III.Translation tRNA translates the code IV.
Protein synthesis rRNA makes the protein
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I.Genetic engineering A.Recombination in nature 1.Mutations
2.Crossing over 3.Selective breeding B.Plasmids DNA bearing units
(rings) that lie outside of bacterial chromosomes used to
incorporate DNA sequences then clone
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B.Restrictive Fragments 1.Restriction enzymes cut DNA at
specific places looks for recognition sequence 2.Gel
electrophoresis sizing DNA fragments D. DNA sequencing PCR
polymerase chain reaction make millions of copies of DNA
sequence
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II.Gene manipulation patented mice, genes inserted into eggs of
organisms A.Gene insertion edit the code, frost resistance, drought
resistance, BT corn B.Genetic engineering of bacteria insert human
DNA into bacteria, human insulin, HGH C.Cloning make an exact
genetic copy, reproductive cloning = Dolly 1.Recombination DNA
Polly, human DNA for factor IX inserted into sheep donor cell
2.Xenotransplantation transplanting of organs from one species to
another
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From bacteria (E. coli) and fungus, fruits and vegetables to
animals, genetic manipulation is becoming more and more common in
our society. In the US market now, 60-70% of the processed foods
are genetically modified. In 2006, United States GMO crops reached
just shy of 135 million acres, with the total global area exceeding
250 million acres! This is a short list of the genetically modified
food crops that are grown in the US today: Corn Soy bean Sugar cane
Tomatoes Potatoes Sweet peppers Bananas Strawberries Zucchini
Pineapples Cocoa beans Yellow squash
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III.New human genetics human genome project, 20,000genes 30,000
genes, 3 billion base pairs A.Genetic disease 1,112 disease related
genes, 400 base pairs identified B.Genetic testing: ethical issues
C.cloning vs. variety, D.diagnostics vs. treatment IV.Genetically
modified foods Golden rice, bacteria + daffodil genes, makes beta
carotene Vitamin A Bt corn & cotton bacteria produces
insecticide Herbicide resistant soybeans Concerns: allergies,
hybridize V. Stem Cells