Science


Lesson 2- Genetic Recombination and Gene Linkage


Protein - a large complex polymer essential to all life that provides structure.

Genetic Recombination

Genetic Recombination - a new combination of genes produced by crossing over and independent assortment.

Formula 2” - used to calculate combinations of genes where n is the number of chromosome parts

Genetic Linkage

Genes close together are Linked Chromosomes

During gamete formation, they travel.

Gene linkage results in an exception to Mendes law of assortment.

Chromosome Maps

Genes far apart may produce crossing over.

Chromosome maps can be created with the crossing over data

Depictions of how genes arrange is a Chromosome Map.


Lesson 3- Applied Genetics


Hybrid- organism that is heterozygous for a particular trait.

Selective Breeding

Selected and passed to future generations is Selective breeding.

Methods of Selective breeding:

  • Hybridization- process of creating hybrids.

  • Inbreeding- 2 closely related organism are bred to have desirable traits.

Test Cross

Test Cross- Used to determine the genotype of the hybrid.


Lesson 4- Basic Patterns of Human Inheritance


Genes- segments of DNA that control the production of proteins.

Pedigrees

Recessive traits are expressed only when the individual is homozygous recessive.

A heterozygous indivdual is called a carrier.

Inheritance of disorders in humans can be achieved by the use of a pedigree.

Recessive Genetic Disorders

  • Two unnafected parents may have an affected child.

  • Indicates both parents are heterozygous ( carriers)

  • Half filled square means that both parents are carriers.

Dominant Genetic Disorders

  • Affected parents can pass the gene to their children.

  • Unnafected parents cannot have an affected child.

Inferring Genotypes

  • Pedigrees can be used to infer genotypes from the observations of phenotypes.

  • Knowing physical traits can determine what genes an individual is most likely to have.

Predicting Disorders


Albinism

Cause: The body doesn’t produce enough melanin.

Effects:

No color

Susceptible to UV damage

Vision Problems

Cure: None, protect skin from UV rays

Cystic Fibrosis

Cause: the gene that codes for a membrane protein defective

Effects:

Excessive mucus production

Digestion and Respiratory failure

Cure: None, Daily cleaning of mucus from the lungs, Mucus thinning drugs.

Galactosemia

Cause: absence of the gene that codes for the enzymes that break down galactose.

Effects

Mental disabilites

Enlarged liver

Kidney Failure

Cure:

No cure, Restriction of galactose in the diet.

Tay-Sachs Disease

Cause: absence of necessary enzymes that break down fatty substances.

Effect:

Many fatty deposits in the brain

Mental disabilites

Cure: No cure, Death by age 5

Huntington’s Disease

Cause: a gene affecting neurological stuff

Effects:

Ability to move deteriorates.

Cure: None

Achonodroplasia

Cause: gene that affects bone growth is abnormal

Effects:

Gian arms and legs

Obese

Cure: None