Genetics

Dominant vs Recessive

•If a gene is dominant, then it will express the trait. •If a gene is recessive, it will only express the trait if the dominant gene is not present. •Each body cell should have 2 copies of a gene for every trait- these are called alleles.

Gregor Mendel

•Mendel described how traits were inherited by studying pea plants. •He did this by crossbreeding several plants and observing the results.

Proteins

•Organic molecules that make up much of our bodies EX: hormones, antibodies, cell membrane and ENZYMES •They are made up of amino acids

Genetic Engineering

•Produce crops/animals that are resistant to certain disease or pest •To treat genetically related disorders

RNA

•Single stranded and contains the bases, ATGC •Transcribes the DNA code in the nucleus

Phenotype

•The outward physical appearance is the phenotype EX: The phenotype of the Rr genotype is round. •What is the phenotype of the rr genotype? wrinkled

DNA

•deoxyribonucleic acid •made of small subunits called nucleotides, which consist of phosphate, sugar and one of four bases •what genes are made up of

Selective Breeding

•oldest form in "genetic engineering" •Cross (or breed) organisms with desired characteristics EX: racehorses, crops

Mutation

Any change in the genetic material of an organism

Genotype

A capital letter is given to dominant traits; a lowercase letter to recessive traits. (Ex- Round peas are dominant to wrinkled peas; the genotype could be RR or Rr for round peas, but must be rr for wrinkled peas)

DNA transcribed to RNA

DNA-->C A G G T A C A A T T C G A T RNA-->G U C C A U G U U A A G C U A

Substitution

One or more nucleotide bases is replaced with a different nucleotide •EX: A A G C<-- T T C C

Addition/Insertion

One or more nucleotide is added to the sequence •EX: A A T T C C G A<-- G

Punnett Square

T T t Tt tt t Tt tt

Genes

The passing of genes from generation to generation

Traits

characteristics that each person has. Ex- eye or hair color Traits are determined by genetic instructions, or genes

Human Geome Project

completed in 2003, scientists have identified all of the genes in the human DNA sequence

mRNA

messenger RNA •transcribes (copies) the DNA code in the nucleus and brings it to the ribosome

Mutagens

mutagenic agents •EX: uv rays, Xrays, Viruses

Carcinogens

mutagens that cause cancer

Deletion

one or more nucleotide bases is deleted •EX: A A C C G <-- T T

tRNA

transfer RNA •carries Amino Acids to the ribosome based on the mRNA code Transcribed RNA code: VAL HIS VAL LYS LEU

Pure vs Hybrid

• Two letters that are both uppercase or lowercase represent a pure (Homozygous) organism: EX: RR = Homozygous dominant rr = Homozygous recessive • An uppercase and a lowercase show a hybrid organism (heterozygous) EX: Rr = Heterozygous round

Pedigree Chart

•A diagram that shows the presence or absence of a particular trait in each member of each generation.