Genetic Variation Flashcards
Outline the four main forms of phenotypic variation.
Morphological - shape/structure of an organism.
Biochemical - chemical structure/composition of an organism.
Physiological - the way individuals carry out metabolic processes/bodily processes.
Behavioural - differences in the way individuals perceive, think and react.
How are mutations the source of novel genetic variation?
Somatic Cells - mutation changes body cells and daughter cells produced from mitosis (cancer).
Gamete Cells - mutation in reproductive cells making traits inheritable through the offspring of a population.
What are the two types of DNA Mutation?
Deletions - deletes a nucleotide; results in a frameshift (can be >1) = garbled message/non-functional - proteins misssing AA.
Insertions - adds a nucleotide; results in frameshift - same result as a deletion.
What are the two causes of a Mutation?
Error in DNA Replication - DNA polymerase will incorporate a non-complementary base into the daughter strand - leads to a mutation.
Radiation - Gamma rays, X-rays, and UV light can interact with compounds in the cell generating; cause chemical damage to DNA.
What are the five types of Chromosome Mutations?
Deletion - loss of part of a chromosome.
Duplication - section of chromosome occurring twice; if part of chromatid breaks off and joins onto the wrong chromatid.
Inversion - breaks in a chromosome, forming back in wrong way; changing the order of genes, disrupt pairing of homologous chromosomes during meiosis.
Translocation - part of a chromosome breaks off and joins to the other (wrong) chromosome.
Non-disjunction - during meiosis a chromosome pair doesn’t separate, one daughter cell has an extra chromosome and the other has one less.
What is a point mutation?
A mutation that affects a single base pair position within a gene.
