Chapter 8 Chromosomes Mutations Flashcards
How do mutations happen?
non homologous crossover or DNA damaging events
Why is crossing over uneven?
occurs between lines and sines
Are chromosomal deletions more lethal in their homozygous state? Heterozygous?
yes, can be because eit uncovers recessive mutations and imbalances gene products
How can you detect non lethal heterozygous deletions?
deletion loops, no inversion
What are the two types of chromosomal duplications?
Tandem (repeated) or reverse (BCCB)
how can duplication contribute to evolution?
when genes are duplicated, they can take on a new function (neofunctionalization) or retain an old function (subfunctionalization)
What can affect gamete viability?
pericentric (with centromere) paracentric (without centromere)
What are the products of a PERIcentric inversion of a heterozygote?
1 normal
2 deletions w/ duplications
1 inversion
What occurs in a PARAcentric inversion of a heterozygote?
meiosis 1: breakage on one arm meoisis 2: contains deletions
1 normal
2 deletions
1 inversion
what ar the two types of segregation sand their products?
adjacent-1
all inviable
alternate
all viable
Describe robertsonian mutation
reciprocal, 21 and 14 fragment lost
Describe philadelphia syndrome
part of chromosome 22 is transferred to 9, but none of 9 is transferred to 22, reciprocal
Euploids contain…. aneuploids contain…..
mono,di,tri,tertralpoid
mono and trisomic
What is caused by non disjuntions?
aneuploidy
what is polyploidy?
changes number of whole sets of chromosomes
