Genome Organization

Question 1

Genotype (genome) + environment =

Answer 1

Phenotype

Question 2

Give an example of a tandem repeat (satellite DNA) and tell why it’s important.

Answer 2

Alpha-satellite repeats.

They are located close to the centromere and may be important in chromosomal segregation during cell division.

Question 3

What are the 4 types of Dispersed Repetitive DNAs?

Answer 3

• Alu Family (SINE-short interspersed repetitive elements)
• L1 Family (LINE- Long….)
• Retrotransposition
• Non-allelic homologous recombination (NAHR)

Question 4

How would you classify a 4 nucleotide long repeat?

Answer 4

Microsatellite (STRs- short tandem repeats):

Occur approximately 5x10^4 times per genome

Question 5

How would you classify a 100 nucleotide long repeat?

Answer 5

Mini Satellite (VNTR- variable number of tandem repeats)

Question 6

What is the primary mechanism that causes gene families to arise?

Answer 6

Gene duplication

Rationale: when a gene duplicates it frees up one copy to vary while the other copy continues to carry out a critical function

Question 7

Name 3 gene poor chromosomes. Hint, if these are trisomic, the embryo may survive. Also, name the associated major diseases with each chromosome

Answer 7

13-Puberty (Patau)
18-Election (Edwards)
21-Drinking (Downs)

Question 8

Which species is most likely to exhibit the highest DUF1220 (on 1q21) copy number?

Answer 8

Humans.

This gene has been positively selected for in primates.

Question 9

What are the diseases associated with 1q21 CNV duplications/deletions?

Answer 9

DUPLICATIONS:
Macrocephaly
Autism

DELETIONS:
Schizophrenia
Microcephaly