2b.5 - Medel and Genetic Diagrams Flashcards
What three important conclusions did Mendel reach?
- Characteristics are determined by ‘hereditary units’
- Heredity units are passed on from each parent, one unit from each
- Hereditary units can be dominant or recessive
What are ‘hereditary units’?
Genes
What are alleles?
Different versions of the same gene
What is a homozygous organism?
It has two alleles that are the same for a particular gene
What is a heterozygous organism?
It has two alleles that are different for a particular gene
What is a genotype?
What allele the organisms has
What is a phenotype?
The actual characteristic
What do you write for a genetic diagram? (4)
- Parent’s phenotypes
- Parent’s genotype
- Offspring’s genotype
- Offspring’ phenotype
What type of allele is cystic fibrosis caused by?
A recessive allele
What letter is cystic fibrosis represented by on a genetic diagram?
F
What is the genotype for a person who has cystic fibrosis?
ff
What is the genotype for a person who is a carrier of cystic fibrosis?
Ff
Name a condition caused by a dominant allele
Polydactyly
What is polydactyly?
Where the baby grows extra fingers or toes
What letter represents polydactyly on a genetic diagram?
D
