SPANGLER SCIENCE

GENETICS

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GENETICS- PPT

GENETICS- NOTES
Terms:

Heredity: the passing of traits (characteristics) from one generation to the next.

Genetics- the study of genes and heredity. How traits are inherited, passed.

Gregor Mendel- The father of genetics. Monk in 1822 studied pea plants to come up with the bases of genetics, that the parents play a roll in the outcome of the offspring.By use of the punnett square could predict the outcome of the offspring.

Genes- made of DNA; found on chromosomes specific traits (characteristics) of an organism.

Alleles- different variations of the gene for a specific trait.
ie: gene for pea plant height, alleles are tall or short.

Dominant- controlling gene; always shows up, covers up the recessive allele.
writen as a capitol letter. ie: T

Recessive- Trait shows only when matched with another recessive allele of the genetic trait, covered up when matched with a dominant allele.
written in lower case letter. ie: t

Homozygous- (purebred) two of the same alleles for a trait.
both genotypes the same; ie: TT or tt

Heterozygous- (hybrid) two different alleles for a trait.
genotype mixed; ie: Tt

Genotype- genetic makeup of an organism.
characteristics written with the alleles; ie TT, tt, or Tt

Phenotype- physical description of an organism.
states characteristic of specific genotype; ie: tall or short

Punnett Square- possible combination of alleles
calculates probability
uses genotypes

Probability- predicted odds, educated guess of the outcomes percentages in different catagories.

TRAITS- characteristics passed from one generation to its offspring

Single gene- traits controlled by a single pair of alleles. 2 options. ie: roll of tongue, widow’s peak

Multiple alleles- traits controlled by many alleles on single gene.
more variations. more than 2 options. ie; blood type, fingerprint blood: AA, Ao, BB, Bo, oo, AB

Codominance- alleles that are both dominant and so join to create the trait. genotype possibilities increased with both alleles. can show both characteristics in phenotype, equal ie: blood type (above)

*Incomplete dominance- intermediate phenotype, blend
ie: color of some flower

Polygenic- more than one gene to decide trait.
different mix of many alleles give variations, wide variety. ie: eye, hair, skin color, height
FF, Ff, ff with GG, Gg, gg = FFGG, FFgG, FFgg,FfGG,FfGg, Ffgg, ffGG, ffGg, ffgg
Mutation- Change. Change on a gene or chromosome to produce a different outcome or product.
Change can be positive, negative or neutral.
Change can occur with the line up of DNA bases to create new protein.
Options of changes are:
1. substitution, replacement; most common.
2. deletion, something taken out, subtracted.
3. insertion, something added into

Environmental factors- factors that effect some traits of individuals. ie: diet, poor nutrition, exercise
medical care, living conditions
environment of where on lives, (air, water, pollutants,weather)

Sex Linked Genes- genes that are associated with the particular sex gene; X or Y. These traits only go to the specific child according to their sex.
The specific gene is on the sex-linked chromosome. These traits are stil dominant or recessive. Though it can be recessive from the mother and shown on the fther because it is the only allele.
ie: color blindness; recessive trait on the X chromosome.

Pedigree- family tree to trace genetic traits.
Usually done in rows across for generations. Male represented as squares. Females represented as circles. Specific traaits shown with shaded shape, carriers have 1/2 shape shaded.

Genetic Disorders- genes go through mutation.
-disruption in DNA.
1. color-blindness: sex-linked X chromosome, recessive
2. sickle-cell anemia: recessive
-rbc-sickle shaped; not enough O2 deliverred, clog vessels
3. hemophilia: recessive X chromosome
rbc-blood doesn't clot reguarly, protein not produced.
4. cystic fibrosis: recessive
-thick mucus in lungs & intestines
-mucus builds up and makes it hard to breathe and slows down digestive enzymes.

Genetic Engineering- Change of DNA.
* can be both positive and negative effects:
+ cure disease, make medicine, produce better food, quantity of food (grains/animals/fruits/vege's, pest resistance
- above can be construed by the one with the knowledge, can be used for bad as well as good. Depends on whose hands the knowledge and power is in.
* designer genes- manipulate individual genes.
transfer genes from one to another.

dnaandhand.jpg

Our genetics decides who we are.

Homozygous D: AA
Heterozygous: Bb
Homozygous R: ee

Genotype = Phenotype
Allele = options of gene/trait

W. T. EICH MIDDLE SCHOOL