Chapter 5 - Genetics (Unit 2) Flashcards
What are Inheritance Patterns?
- Predictable patterns (transmission of traits)
- Inherited traits -> hereditary traits
What did Gregor Mendel do?
- Studied pea plants + Inheritance patterns
What is Locus?
- location of a gene on a region of a chromosome
What is the P generation?
What is the F1 generation?
What is the F2 generation?
P - parental generation
F1 - First generation + hybrid (PxP)
F2 - Second generation (F1 x F1)
What is Genotype?
- The genetic make-up of an organism
Ex: set of genes/alleles
What is Phenotype?
- Physical expression/appearance that an organism shows (Ex: looks)
What are Hybrids?
- Cross of two diff true breeding organisms
- F1 generation
What are Monohybrids?
- Offspring of parents diff in only one trait/gene
What does Homozygous mean?
- Both alleles are dom or recess
(Ex: BB/bb)
What does Heterozygous mean?
- Alleles are always dom AND recess
- Dom always shows
(Ex: Bb)
What are Alleles?
- exist in genes
- Either dominant or recessive
- Homozygous or Heterozygous
- Each gamete only carries 1 allele for each trait
What is Mendel’s Law of Segregation?
- During gamete formation
- Pair of alleles responsible for each trait separate -> each gamete has one allele for each trait
What is Mendel’s Law of Independent Assortment?
- During gamete formation
- Alleles segregate independently of each other
Ex: One trait is not accompanied by another
(Ex: Blue eyes + Blonde hair)
What is a Dihybrid Cross?
- Involves two separate traits
- Ex: colour and length
Describe Incomplete Dominance
- Mix of traits
- An Inheritance pattern where the phenotype of a heterozygous individual falls in bw both parent’s phenotypes
- Same letter is used (Ex: R & r )
Ex: Snap Dragons
Describe Codominance
- Both traits show separately
- Both alleles are completely expressed at the same time
- Is heterozygous + has its own phenotype
- Different letters are used (Ex: R + W)
Ex: Cattle (Red + White -> Roan)
Ex: Blood type is Codominant
What are Multiple Alleles?
- Many genes have more than 2 alleles
Ex: ABO blood type
Describe Blood Types + Alleles
Four types:
1. A
2. B
3. AB
4. O
I to the pwr of A
I to the pwr of B (Co- dominant)
i is recessive
Describe Blood type A
- Possesses A carbohydrates
- Has Anti-B
Describe Blood type B
- Possesses B carbohydrates
- Has Anti-A
Describe Blood type AB
- Has carbohydrates A + B
- No Anti Bodies
- Universal recipient
Describe Blood type O
- Has NO carbohydrates
- Has Anti - A&B
- Universal Donor
What is a Polygenic Trait?
- Has a range of phenotypes
- Additive effects of multiple genes
(Ex: eye colour/height) - 60 genes -> skin colour
What are Environmental Influencers?
- Diff allele combinations = variety in phenotypes
- Nature (heredity)
- Nurture (environment)
- Influence phenotype
(Ex: humans -> nutrition and sunlight can impact growth)
