Genetic Inheritance Flashcards
What does hereditary mean?
Passing of traits from parent to offspring
What are traits (phenotype) influenced by?
Multiple genes and the environment
What is true breeding?
When the plants self-pollinate, all their offspring are all of the same variety.
What is hybridisation?
Mating of two varieties
What is mono hybrid cross?
A cross between two parents that breed true for different versions of a single trait
What was Mendels first principle?
Inheritance traits are governed by hereditary factors
What was mendels second principle?
The phenotype depends on which version of each allele it inherits.
What was mendels third principle?
Two alleles fro each trait separate during gamete formation and then unite at random at fertilisation
What are the 4 types of genetic diseases?
Single gene defects
Chromosome abnormalities
Multi factorial disorders
Cancers
What are single gene defects?
Caused by changes or mutations that occur in the DNA sequence of a single gene
What are the different mechanisms of inheritance due to single gene defects?
Autosomal dominant (single mutated allele)
Autosomal recessive (both mutated allele)
X linked recessive (present on the X chromosome)
What are the different mutations of single gene defects?
Missense mutations (alter a codon)
Nonsense mutations (change codon to stop codon)
Frameshift mutations (insertion or deletion of a base)
Promoter mutations (affect gene transcription)
What are the two types of chromosomes abnormalities?
Numerical abnormalities (either missing a chromosome or has more than two)
Structural abnormalities (chromosome structure altered)
What can cause multi factorial disorders?
Familial clustering
Additive effects of many genes with environment factors
What are cancers also influenced by?
Environmental and lifestyle factors at a somatic level resulting from mutated or abnormally expressed genes
