Chapter 13 - Chromosomal Aberrations and Transposition

Question 1

What causes the loss of genetic materials?

Answer 1

• Chromosomal deletion
• Missing Chromosome(s)

Question 2

What causes gain of genetics materials?

Answer 2

• Duplication
• Extra chromosome(s)

Question 3

What are the relocation of genetic materials?

Answer 3

• Translation
• Extra Chromosome(s)

Question 4

Euploidy is …

Answer 4

complete haploid sets of chromosome in multiples

Question 5

Meiosis works in eukaryotes with an (even/odd) number of chromosomes because the need to (pair/unpair) with homologs.

Answer 5

• even
• pair

Question 6

Why will 3n, 5n, 7n and etc fail in meiosis?

Answer 6

Because some chromosomes will not pair with a homolog

Question 7

Polyploidy

Answer 7

where organism pass extra haploid sets of chromosomes

Question 8

Autopolyploidy

Answer 8

polyploids with multiple chromosome sets derived from a single taxon.

Question 9

Allopolyploidy

Answer 9

duplication of euploid chromosome set form a combination from different species

Question 10

Aneuploidy

Answer 10

number of chromosomes in a cell differs from the wild type by a portion of haploid set. It is often deleterious and can result in early death of embryos.

Question 11

Monsomic

Answer 11

missing one copy of one chromosome (2n-1)

Question 12

Trisomic

Answer 12

an additional copy of one chromosome (2n+1)

Question 13

Nullisomic

Answer 13

No copies of a particular chromosome (2n-2)

Question 14

Disomic

Answer 14

in haploid organisms, when one of the chromosomes is present twice (n+1)

Question 15

How does aneuploidy occur?

Answer 15

Nondisjuction
- failure if segregation of chromosomes during meiosis (or mitosis)
- More can go wrong during meiosis I

Question 16

Which gender does aneuplodidy occur more in?

Answer 16

Female

Question 17

Unequal crossing over can lead to what?

Answer 17

This can lead to chromosomal rearrangement or aberation.
*It happens during recombinations and misalignment of homologous chromosomes.

Question 18

Paracentric inverison

Answer 18

do not span the centromere

*They may experience phenotype abnormalities if genes were affected on the breakpoint and may be infertile due to complication in meiosis

Question 19

Pericentric inversion

Answer 19

span the centromere

Question 20

Translocation

Answer 20

Chromosomal breakage followed by reattachment of the broken segement to a nonhomologous chromosome

Question 21

The movement of transposons…

Answer 21

• Transposons recognizes inverted repeats and excises the element
• Staggerd cut is made in genomic target site
• Original copy remains only if it is rerpair by recombination pathway and if it’s repaired by non-homologous end joining

Question 22

Retrotranspons

Answer 22

• They can copy and paste themselves into different locations in the genome.
• Consists of LINEs and SINEs