Genes and Chromosomes I: Mendel and the Gene Flashcards
Mendelian Genetics
When talking about Mendelian Genetics, we are referring to one gene, with a dominant nad recessive allele
Gene
A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA
Genetics
The scientific study of heredity and hereditary variation
Inheritance
The process by which genetic information is passed from parent to offspring
Character
An observable heritable feature
a sort of category of traits
Trait
Any detectable variation in a genetic character (phenotype)
Why were pea plants so successful in Mendel’s experiment?
In pea plants, one characteristic is dependent on one gene.
Alleles
Versions/Flavors of genes
Alternative forms of a gene reside at the same locus on homologous chromosomes
Law of Segregation
The 2 alleles for each character segregate into different gametes
gametes get one of two alleles from the diploid organism producing it
In anaphase I, homologous chromosomes separate, where the two alleles for each gene separate during gamete formation
What is the test cross and what is its purpose?
The test cross is when you cross an organism (parent) with another that is homozygous recessive for a certain trait in order to find the parent’s phenotype.
Law of Independent Assortment
What stage of meiosis does this relate to?
Each pair of alleles segregate independently of other pairs during gamete formation
- Is related to metaphase I when homologous chromosomes line up randomly. Alleles of genes on nonhomologous chromosomes assort indepenently during gamete formation.
Characters are inherited separately and are expressed separately
When does Independent Assortment not hold true?
- When two characters are on different chromosomes
- When two characters are on the same chromosome
When two characters are on the same chromosome
Multiplication Rule
When trying to calculate the probability of a single genetic event, multiply the probabilities of each event
Addition Rule
When trying to calculate the probability of more than one mutually exclusive genetic event, just add their probabilities together
