6.2 Patterns of inheritance Flashcards
Define genotype.
Genetic makeup of an organism
Define Phenotype
Visible characteristics of an organism
What is the Phenotype influenced by?
the Genotype and environment.
How can genetic factors cause phenotypic variation?
Through mutations, involves changes to structure of DNA.
Sexual reproduction may also lead to genetic variation.
What are mutagens?
Certain physical and chemical agents that increase the rate of mutation.
What are some mutagens that are physical agents?
X-rays, Gamma rays, UV light
What are some mutagens that are physical agents?
Mustard gas, Nitrous acid, Aromatic amines, Reactive oxygen species.
What are some mutagens that are biological agents?
Some viruses, Food contaminants
What does it mean when mutations that occur during gamete formation are described as persistent and random?
Persistent = they can be transmitted through many generations without change
Random = They are not directed by a need on the part of the organism in which they occur.
When does chromosomal mutations occur?
During Meiosis.
What happens if deletion occurs?
Part of a chromosome that contains genes is lost
What happens if inversion occurs?
A section of chromosomes may break off, turn through 180 degrees and then join again.
-Although still present, some genes may be too far away from their regulatory nucleotide to be expressed
What happens if translocation occurs?
A piece of one chromosome breaks off and then becomes attached to another chromosome.
-May interfere with regulation of genes on the translocated chromosome
