Mendelian Genetics and Human Pedigrees Flashcards
What are pure breeds?
Homozygous
What is the first cross known as?
F1 generation
What were Mendels proposals of inheritance (using genetic language)?
- In a diploid individualm genes have two alleles, each on a chromosome of a homologous pair
- In the pair one allele is dominate, other recessive
- Two alleles of a single gene separate independently during gamete formation
What is a genotype?
Gentic makeup
What is a phenotype?
Physical expression
What is homozygous?
2 of the same alleles
What is heterozygous?
2 different alleles
What is test cross?
How to tell if the origal generation is a pure breed or not
What do we test against in test cross?
Homologous recessive
What is a dihybrid cross?
Two characteristics with two traits. How two independent characters behave.
What are alleles?
Different versions of genes
What is product law?
Predicts the frequency with which two independent events will occur simultaneously. Combined probabilities.
What do Human Pedigrees show?
Mendelian diseases
How are Human Pedigrees arrange?
- Generations in rows
- Double line = married to someone you’re related to
- Roman numerals to number generations
What are the different symbols in a Human Pedigree?
Males - square. Females - circle.
What was albinism the result of?
Mutation in the enzyme involved in the production of melanin. Autosomnal recessive disorder.
What are the different types of recessive disorders?
X-linked or autosomnal
How common are recessive disorders?
Rare - low frequency
How do you recognise an Autosomnal Recessive Disorder?
Appears in the progeny of unaffected parents. Affected progeny includes both females and males.
What are some examples of Autosomnal Dominat Disorders?
Non-collagenous extracellular matrix protein
Cartilage oligometric matrix protein
Pseudoachondroplasia - dominant allele interfere with growth of long bones
How do you recognise a dominant disorder?
Affected males and females in each generation
Shows affected men and women transmitting the condition to equal proportions
How do you recognise an X-Linked Recessive Disorder?
Mainly in the males - females can be carriers
