Fundamentals of Genetics and Mutations Flashcards
What is the unit of inheritance?
A gene.
Define a locus.
The position of a gene on a chromosome.
Define gametogenesis.
The process in which cells undergo meiosis to form gametes.
How many copies of each gene are carried per gamete?
One copy.
How many copies of each gene are carried per zygote?
Two copies.
What are the phenotypic ratios for independent assortment?
9:3:3:1
Why do plants have so many genes?
They are unable to move so must be able to tolerate a wider range of environmental conditions.
Are males or females hemizygous?
Males - they only have one copy of the X chromosome.
What is crossing-over?
The exchange of genetic information between homologous chromosomes.
What is produced from crossing-over?
A hybrid chromosome and genetic variation.
How do you calculate recombination frequency?
(Number of Recombinant Progeny/Total Number of Progeny) X 100
Define a mutation.
Any heritable change in the DNA sequence.
Define a transition mutation.
Substituting a purine for a purine or a pyrimidine for a pyrimidine.
Define a transversion mutation.
Substituting a purine for a pyrimidine or vice versa.
Define a silent mutation.
A change to the codon that has no effect on the amino acid.
Define a missense mutation.
A change to the codon for a specific amino acid to a different amino acid.
Define a nonsense mutation.
A change to the codon for a specific amino acid to a STOP codon.
Define an INDEL.
Small insertions or deletions of bases.
How can replicating DNA gain or lose single bases?
Via replication slippage.
How can large insertion mutations occur?
Either by transposon mobilisation, virus insertion or retroposition.
Define transposon mobilisation.
PLACEHOLDER
Define virus insertion.
PLACEHOLDER
Define retroposition.
PLACEHOLDER
What mutations have the biggest effects?
Translocation, inversion, duplication and chromosome fusion.
