Gene Mapping
A homozygous recessive parent crossed with an unknown genotype parent.
What is a testcross?
Accumulation of proteins in the nurse cells surrounding the egg control the development of snail shell coiling.
What is an example of maternal effect?
An amino acid sequence has a stop codon in the middle of the translated region. What will result?
A premature stop in translation-no function protein.
Why is familial down syndrome not always penetrant in all offspring?
Depends on the balance of gametes following meiosis.
Define the difference between genetic mapping and sequencing.
Physical distance vs. actual sequence.
A normal mother and mutant father have mutated babies, but a mutant mother and normal father have normal babies.
What is an example of genomic imprinting.
A mutation occurs in an intron. What will happen?
Probably nothing.
Why are older mothers more prone to having babies with genetic mutations?
Age of proteins associated with DNA segregation in gametes.
An offspring has a mitochondrial disease. Which parent did they inherit this from?
The mother only transmits organelles to offspring.
Name two reasons how a mutation would be affected by position effect.
1. movement to a position next to a regulatory sequence.
2. movement to a heterochromatic region.
Why are polyploids unable to reproduce (think seedless watermelon)?
There is an odd number of chromosome sets so there can't be complete synapsis in meiosis.
How are somatic cell mutations transmitted to daughter cells?
DNA replication
Why can't an allodiploid organism reproduce?
There are no homologous chromosomes to synapse during meiosis.
Cancer, senesence, apoptosis
What is the result of faulty DNA repair mechanisms?