Lecture 1 - 2 Flashcards
Genes
Come in multiple versions of alleles (Tt vs tt)
What does genotype confer?
Phenotype
What does DNA carry?
Genetic Info
Where are Genes located in?
Chromosomes
How is Genetic Information transferred?
From DNA to RNA to Protein
Gene
A genetic factor (region of DNA) that helps determine a characteristic
Allele
One of two or more alternate forms of a gene
Locus (location)
Specific place on a chromosome occupied by an allele
Genotype
Set of alleles possed by an individual organism
Heterozygote
An individual organism possessing two different alleles at a locus
Homozygote
An individual organism possessing two of the same alleles at a locus
Phenotype or Trait
The appearance or manifestation of a character
What is a dihybrid cross?
Crossing two different types of traits (yellow or round and green or wrinkled)
What ratio does a dihybrid cross always produce?
9:3:3:1
How many gametes do homozygotes produce?
1
How many gametes do heterozygotes produce?
1
What are recessive mutations?
Usually dominated by wild type and require two mutated copies for disease to develop
Null/Amorphic Alleles
A nonfunctional protein is produced OR no protein is produced (enzyme no longer recognize substrate)
Mutation is in the promoter region sports no RNA is produced.
Hypomorphic Alleles
Poorly functioning protein is produced OR reduced amounts of a normally functioning protein is produced
What are Autosomal Dominant Traits
Typically does not skip generations, and one copy of a mutated (changed) gene from one parent can cause the genetic condition.
What are the alleles for an Autosomal Dominant Trait?
bb - Normal
Bb - Affected Heterozygote
BB - Affected Homozygote
Dominant Hypermorphic Alleles
- Negative phenotypic consequences due to the over-production of a normal protein OR
- Negative phenotypic consequences due to the production of a protein with increased activity levels.
Neomorphic Alleles
- Negative phenotypic consequences due to the presence of an altered protein that has a new function.
- Negative phenotypic consequences when the altered protein interferes with the wild type protein (Dominant-negative allele)
For traits that are rare and dominant, why are affected individuals most likely to be heterozygous (Bb) and not BB
The only way to produce BB would be to have two heterozygous individuals mate, which is rare to have two people with the disease mate
