ch 14

Question 1

what affect can chromosomal rearrangement?

Answer 1

change the structure of the chromosome and can either cause a loss or gain of part of the chromosome that is caused by chromosomal breakage or illegitimate -> can lead to mutations

Question 2

what are illegitmate CO?

Answer 2

regions of repeats on the same chromosome or a separate one that can cause un=/illgitamete CO

Question 3

Chromosomal deletion

Answer 3

Part of the chromosome is missing due to breakage and the parts that are leftover are glued back together.

Question 4

can hemizygotes survive chromosome deletion? why do mutant phenotypes happen

Answer 4

no
Mutant phenotypes can happen because of haploinsufficiency (gene dosage is too low), vulnerability to mutation (only 1 normal if something happens to it then oh well), and loss of dominant allele (recessive may show since the dominant allele was deleted)

Question 5

what is chromosomal inversion?

Answer 5

The sequences are facing in opposite directions where the breakage flips around and reattaches.

Question 6

what are the two types of chromosomal inversion?

Answer 6

peri(includes centromere)/paracentric (excludes centromere)

Question 7

what kind of affect does chromosomal inversions have on the phenotype?

Answer 7

if it is a large enough region it can result in lethality but this only really happens when the inversion is in the middle

Question 8

what are the two types of paracentric fragments?

Answer 8

acentri: (lacks centromere) is lost in the gamete
-dicentric (lacks 2 centromeres and happens during anaphase) - breakage at random points

Question 9

chromosomal duplications

Answer 9

the repeats on homologous chromosomes happen in multiple places causing uneven CO

Question 10

what are the weo types of chromosomal duplications?

Answer 10

-tandem duplication :duplicated regions are next to one another and are on the same chromosome -> this can lead to unequal CO)
-non tandem repeats (duplicated regions that do not lie next to each other on other chromosomes)

Question 11

what kind of effect can chromosomal duplications have on the phenotype?

Answer 11

• does not usually affect the progeny but it can when the trait is senstitive to the increased numbers or if the gene is on the border border of the duplication and has alternative expression because of the new chromosome environment.

Question 12

chromosomal translocation

Answer 12

-The two chromosomes are not homologous at all but have similar repeats
-Two nonhomologous chromosomes interact and so part of one chromosome is transferred to another or both chromosomes swap material

Question 13

Pseudolinkage

Answer 13

genes on either side of the breakpoint behave as if they are linked (genes that are on separate chromosomes act like they are linked)

Question 14

Transposable elements

Answer 14

small DNA segments capable of relocating within the genome, either on the same chromosome or a different one, akin to their dynamic movement. Their mobility frequently disrupts normal gene expression patterns.

Question 15

what are the two ways transposable elements can move around?

Answer 15

-Retrotransposons: transpose by reverse transcription of RNA intermediate
-DNA transposons:move their DNA directly without the requirement of an RNA intermediate

Question 16

what are autonomus and nonautonomus in terms of transposable elements?

Answer 16

-Autosomus: can move themselves
-Nonautosomes: requires help from autonomous elements to mov