L18 - Chromosome mutations

Question 1

Types of chromosomes

Answer 1

Telocentric, Acrocentric, Metacentric, Submetacentric

Question 2

Fluorescence in situ hybridisation

Answer 2

can detect structural abnormalities in the chromosomes

Question 3

Types of chromosomal mutations

Answer 3

Numerical and structural

Question 4

Polyploidy

Answer 4

multiple sets of chromosomes

Question 5

Triploidy

Answer 5

3 chromosomes in all sets (3n)

Question 6

Tetraploidy

Answer 6

4 chromosomes in all sets (4n)

Question 7

Aneuploidy

Answer 7

the condition of having abnormal number of chromosomes

Question 8

Non-disjunction

Answer 8

failure of homologous chromosomes (meiosis 1) or sister chromatids (meiosis 2) to separate at anaphase

Question 9

Nullisomy

Answer 9

• 2n-2
• Loss of one homologous pair of chromosomes
• no viable human examples

Question 10

Monosomy

Answer 10

• 2n-1
• loss of a single chromosome
• one viable human example (turner syndrome) 45, X

Question 11

Trisomy

Answer 11

• 2n+1
• one extra chromosome
• several viable human syndromes

Question 12

Down Syndrome

Answer 12

• trisomy chromosome 21
• Many developmental abnormalities, low IQ
• only autosomal trims to survive to adulthood, but life expectancy low

Question 13

2 Human autosomal trisomies survive to birth

Answer 13

• Patau syndrome: trisomy chromosome 13

- Edwards syndrome: trisomy chromosome 18

Question 14

Inversions of structural chromosomal abnormalities

Answer 14

1) Pericentric: includes centromere

2) Paracentric: one chromosome arm

Question 15

Translocations (change in position of chromosome segments)

Answer 15

A) Interchromosomal

i) Reciprocal - swooping over between 2 chromosomes
ii) non-reciprocal - no swooping, insertion of a region into other chromosome

B) Intrachromosomal
- join itself into the same chromosome but wrong position

Question 16

Synteny

Answer 16

conservation of gene order in different species