Inheritance Flashcards
Making Gametes
when meoisis occurs (making sperm and eggs)
- homologous chromosomes separate
- then chromosomes separated
- some gametes get 1 chromosome(chromatid) : 1 allele
If a parent is homozygous for a gene:
All gametes get the same allele
If a parent is heterozygous for a gene:
half the gametes get one allele and half get the other
Making Babies
Fertilization: union of sperm and egg
- each gamete contributes 1 allele of each gene
- offspring get 2 alleles of each gene
- offspring cna be homozygous or heterozygous depending on which gametes/alleles
Punnett Square
is used to help determine the genotype of offspring or parents
Gregor Mendel
did the foundational work for genetics/inheritance
- worked with pea plants
- -pollen/sperm and eggs
- -self fertilization
- -cross fertilization
- he cross fertilized true breeding plants in an experiment
cross fertilization
transfer pollen from 1 plant to another
self fertilization
the plant uses its own pollen
true breeding
the offspring all come out the same
Test Cross
crossing individuals in question with individuals who are homozygous recessive for that trait
Law of Independent Assortment
alleles of 1 gene distribute to gametes independently of alleles of another gene-on different chromosomes
-Doesn’t work for genes on the same chromosome
Sex linked genes
genes on the X or y chromosome
-males and females have different copies of every gene
Incomplete Dominance
- Homozygous for allele 1 = 1st Phenotype
- Homozygous for allele 2= 2nd Phenotype
- Heterozgous = intermediate Phenotype
- -flower color, hair texture
Codominance
Alleles are codominant when they are both expressed in the heterozygote/ hybrid
- -Homozygous pink= pink flowers
- -Homozygous white= white flowers
- -Heterozygous= flowers that are both pink and white
Multiple Alleles
1 gene: 2 alleles combination on many different alleles results in many different phenotypes
–blood type, hair color (except gingers)
