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
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.
Homozygous- (purebred) two of the same alleles for a trait.
both genotypes the same; ie: TT or tt
(hybrid) two different alleles for a trait.
genotype mixed; ie: Tt
Genotype- genetic makeup of an organism.
written with the alleles; ie TT, tt, or Tt
Phenotype- physical description of an organism.
of specific genotype; ie: tall or short
Punnett Square- possible combination of alleles
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
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
Change can be positive, negative or neutral.
Change can occur with the line up of DNA bases to create
Options of changes are:
1. substitution, replacement; most common.
2. deletion, something taken out,
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,
2. sickle-cell anemia: recessive
-rbc-sickle shaped; not enough O2 deliverred, clog vessels
recessive X chromosome
rbc-blood doesn't clot reguarly, protein not produced.
4. cystic fibrosis: recessive
mucus in lungs & intestines
-mucus builds up and makes it hard to breathe and slows down digestive enzymes.
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
transfer genes from one to another.