Genes, Chromosomes and Cell Division ✓

Question 1

Chromosome abnormalities

Answer 1

Balanced chromosome rearrangement
Unbalanced chromosome rearrangement
Aneuploidy
Translocation
Specific karyotypes
insertions or deletions

Question 2

Balanced chromosome rearrangement

Answer 2

all the chromosomal material is present

Question 3

Unbalanced chromosomal rearrangment

Answer 3

Extra or missing chromosomal material, usually 1 or 3 copies of a gene
Causes major developmental problems

Question 4

Aneuploidy

Answer 4

whole extra or missing chromosome
X chromosome aneuploidy better tolerated due to x inactivation

Question 5

Translocation

Answer 5

rearrangement of chromosomes
two types, robertsonian or reciprocal

Question 6

robertsonian translocation

Answer 6

two acrocentric chromosomes stuck endo to end
increased risk of trisomy in pregnancy

Question 7

reciprocal translocation

Answer 7

two broken off chromosome pieces of non-homologous chromosomes are exchanged

Question 8

Specific karyotypes

Answer 8

47XY +21
47XY +14
47XY +18
45X
47XXY

Question 9

47XY +21

Answer 9

Down’s Syndrome

Question 10

47XY +14

Answer 10

causes miscarriage

Question 11

47XY +18

Answer 11

Edward’s syndrome

Question 12

45X

Answer 12

Turner syndrome

Question 13

47XXY

Answer 13

Klinefelter syndrome

Question 14

insertions or deletions

Answer 14

missing or duplicated material
microdeletions can also happen

Question 15

microdeletion

Answer 15

too small to be seen on a chromosome using light microscope

Question 16

Somatic Mosaicism

Answer 16

Refers to the occurrence of two genetically distinct populations of cells within an individual, derived from a post-zygotic mutation
may only affect an area of the body

Question 17

Can somatic mosaicism contribute to cancer?

Answer 17

when it changes to a chromosomal abnormality, it could activate an oncogene or delete a tumour suppressor

Question 18

can somatic mosaicism be passed onto childern?

Answer 18

no