Patterns of Inheritance Flashcards
What is a genotype?
Genetic makeup of an organism
What is a phenotype?
The visible characteristics of an organism
What are the physical mutagenic agents?
- X-rays
- Gamma rays
- UV light
What is a random mutation?
A mutation that is not directed by a need on the part of the organism in which they occur
What is a persistent mutation?
A mutation that can be transmitted through many generations without change
What is a deletion mutation in meiosis?
Part of a chromosome containing genes and regulatory sequences is lost
What is an inversion mutation in meiosis?
A section of a chromosome may break off turn 180º and then join again, all genes are still present but some may be too far away from their regulatory nucleotide sequences (transcription factor) to be expressed
What is a translocation mutation in meiosis?
A piece of one chromosome breaks off and attaches to another chromosome, this may interfere with the regulation of genes on the translocated chromosome
What is a duplication mutation?
A piece of a chromosome may be duplicate, this leads to over expression of genes which can be harmful as certain proteins may disrupt metabolism if too many are produced
What is a non-disjunction mutation?
Where a pair of chromosomes fails to separate in anaphase 1 or a pair of chromatids fail to separate in anaphase 2, this leaves one gamete with an extra chromosome and if that gamete is fertilised with a normal gamete then the child will have down syndrome
What is aneuploidy?
Where the chromosome number of a gamete is not an exact multiple of the haploid number for that organism, this is due to chromosomes failing to separate during meiosis
What is polyploidy?
Where a diploid gamete fuses with a haploid gamete or another diploid gamete, the resulting organisms are triploid and tetraploid respectively
