User:Atcovi/Science/Genetics


 * See also: User:Atcovi/Science/Genetics/Putting All the Terms Together and User:Atcovi/Science/Genetics/Problems

Genetics: Study of heredity. Hybrid: Offspring of two different breeds (mule). Purebred: Offspring of the same two breeds (Arabian horse).
 * Dominant vs. Recessive
 * Dominant: In a pair of alleles, stronger allele is visible--in capitals.
 * Recessive: Weaker allele, hidden allele, lowercase letter.
 * Genotype vs Phenotype
 * Genotype: Genetic make up of an inidivudal.
 * Phenotype: Physical characteristics that you can see.
 * Homozygous vs. Heterozygous
 * Homozygous: Purebred, both alleles in a pair are the same.
 * Heterozygous: Hybrid, alleles in a pair are different.

Who is Mendel?

 * Where is he from?
 * Czech Republic
 * What did he do?
 * Bred pea plants to study inheritance.
 * Why is his work important?
 * Discovered basic principles of heredity.

Genes and Dominance
Trait: Specific characteristic (ex: seed color or pod color in a pea plant).
 * 1) Gene: Piece of DNA for a specific trait on a chromosome.
 * 2) Allele: Alternate form of a gene with a slight difference in DNA base sequences ($$A$$ vs. $$a$$).
 * 7 traits coded for by a gene that Mendel studied in pea plants
 * 1) Shape
 * 2) Color
 * 3) Coat color
 * 4) Pod shape
 * 5) Pod color
 * 6) Flower position
 * 7) Plant height

Patterns of Heredity

 * Single Allele Traits - Traits that are controlled by a single dominant allele or homozygous recessive alleles.
 * Multiple Alleles - Traits controlled by more than 2 alleles for the same gene.
 * Codominance - Traits which have a heterozygous genotype where both alleles have equal expression.
 * Incomplete Dominance - Traits which have a heterozygous genotype that is intermediate between the dominant and recessive allele.
 * Sex-linked Traits - Traits that appear on the 23rd pair of chromosomes (the chromosome that determines gender) and are normally found in the $$x$$ chromosome.
 * Polygenic Traits - Traits controlled by 2 or more genes.