Flashcards in Session 15: Mutations Deck (18):
What is a mutation?
A change in the DNA sequence
A mutation can arise from what?
DNA replication errors made during cell division
Exposure to ionising radiation
Exposure to chemicals
Infection by viruses
What is the name given to mutations that occur in the eggs or sperm, affect all cells in the body and can be passed on to offspring?
Germ line mutations
What is the name given to a mutation that occurs in a boy cell and is not passed onto offspring
Why do RNA polymerases not need to proofread like DNA polymerases?
The cell will be making multiple copies of the RNA, it is unlikely to make the same mistake again i exactly the same place
RNAs are quickly degraded so the bad copy will be removed
RNAs are not inherited molecules and won't be passed down from generation to generation (Not as consequential)
What is the role of the mitochondria?
To produce energy
Mitochondria DNA can suffer from mutations in the germ line or somatic mutations?
Germ line mutations in the gene can be what three things?
Which gene mutations in the germ line leads to a frame shift?
Insertion and deletion
Germ line mutations in the chromosome can result from what?
What is the chromosome and chromatid number at meiosis I?
Chromatid: 92 (genetic material is doubled)
What is the chromosome and chromatid number at meiosis II?
What is the chromosome and chromatid number at the end of Meiosis?
Can mitosis produce a chromosomal mutation?
Yes, errors may occur during metaphase when the chromosomes align at the metaphase plate
What could happen if there was a mitotic chromosomal mutation in one of the 2 cells at the 2 cells stage or 1 of the 4 cells at the 4 cell stage etc. during early embryogenesis?
Result in a mosaic individual: an individual with two or more populations of cells with different genotypes
What are the possible outcomes if a very early embryo was exposed to radiation?
Increased risk of cancer when born
What features allow a germ cell mutation to be inheritable?
Not be lethal to the gamete
Not impair gamete function
Not be lethal at fertilisation
Allow the production of a viable adult with normal reproductive capacity