Genetics-Part One

1) Mendel's work & beyond

a) pea plants / self pollination / pure / cross pollination

b) Mendel's Conclusions

1) genes occur in pairs

2) one member of a pair may prevent the other member from working- dominant/recessive (Law of Dominance)

3) gametes get one member of each pair (Law of Segregation)

4) each pair of genes separates independently from other pairs (Law of Independent Assortment)

c) vocab- pure / homozygous

hybrid / heterozygous

alleles

genotype / phenotype

d) Punnett Square

f) Incomplete dominance (red/white/pink)

g) Co-dominance (red/white/roan)

h) multiple alleles blood types

i) polygenic traits

j) Crosses with two traits

2) Sex Determination

a) Morgan and fruit flies- Drosophila

b) XX and XY - sex chromosomes / autosomes

c) sex linked genes - color blindness / hemophilia / Duchenne MD / carriers

3)Other Stuff

a) Sex Limited genes

b) Sex influenced genes

c) Holandric genes

d) homeotic genes

e) oncogenes

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Genetics- Part 2

1) Mutations

a) Germ - sex cell- passed on

b) Somatic- body cell- not passed on

c) chromosomes mutations- deletions, inversions, translocations, non-disjunction

d) Non-disjunction - Monosomy / Trisomy / Trisomy-21 (Down's Syndrome) Polyploidy

e) Gene mutations

1) point mutations- one base affected

substitution- one wrong base - one wrong codon- one wrong amino acid-

frame shift- one missing base - messes up all the following codons

g) mutagens

h) mutations/cell division - skin / embryos / bone marrow / cancer cells

2) Genetic Screening-

Pedigree

Tests for Genes

Karyotypes

Pre-natal- Amniocentesis / CVS

Ethnic groups/ family history

carriers marrying

3) Genetic Diseases

PKU

Sickle Cell

Tay-Sachs

Cystic Fibrosis

Huntingtons

Trisomy-21

Turners' Monosomy-X

Kleinfelters

4) Other Stuff

genome

gene pool

Nature/Nurture twin studies

6) Genetic Engineering

a) restriction enzymes- break DNA into pieces at specific places along the molecule

b) PCR- polymerase chain reaction- makes copies of DNA pieces

c) Recombinant DNA- combining DNA from two different cells

produce a transgenic organism

examples- 1) putting human DNA into a bacteria so that the bacteria will make a human protein- insulin-

2) genetically altered foods

3) Gene therapy- CF

d) DNA "fingerprinting"

1) can identify the source of a DNA sample

2) can compare species for evolutionary relationships

3) Process- a- use restrictive enzymes to cut DNA into fragments- fragments sizes vary from person to person

RFLP b- separate these fragments using gel electrophoresis

c- tag these fragments with radioactive elements- expose to film

PCR- copies DNA sample to get enough for RFLP

RFLP = Restriction Fragment Length Polymorphism