Module 3 Section 6

Question 1

Define genome

Answer 1

-the complete set of genetic material encoded in a cell or virus
-does NOT include DNA from organelles (ie. mitochondria)
-Human genome =23 chromosomes
22 autosomes, 2 sex

Question 2

Intronic and intergenetic regions

Answer 2

-can contain regulatory sequences (ie. enhancers)

Question 3

The gene unit

Answer 3

• regulatory regions (UTRs, promoters)
• Introns
• Exons

Question 4

functional DNA

Answer 4

• improves an organisms fitness
• the functional components are highly conserved (sequence-wise)
• contains coding and non-coding DNA

Question 5

non-functional DNA

Answer 5

-has no known biological contributions

Question 6

coding DNA

Answer 6

-codes for a specific protein

Question 7

non-coding DNA

Answer 7

does NOT code for a protein

Question 8

What percentage of the genome codes for proteins?

Answer 8

1.5%

Question 9

When considering all components of the gene unit, protein coding genes make up approximately what percentage of the human genome?

Answer 9

approx 33% (1/3)

Question 10

Homolog

Answer 10

• two genes with a demonstrable sequence similarity
• implies evolutionary relationship
• independent of functional relationship

Question 11

Orthologs

Answer 11

• 2 genes in a different species with a clear sequence and functional relationship
• derived from the gene in a common ancestor

Question 12

Paralogs

Answer 12

• related genes within the same species

- ie. gene families

Question 13

Chromosome structure

Answer 13

P-arm
-shorter arm of the chromosome
Q-arm
-longer arm of the chromosome
Centromere

Question 14

Single nucleotide polymorphism (SNPs)

Answer 14

-genomic base pair change that helps distinguish species from each other or one subset of individuals in a population

Question 15

Large genomic rearrangements

Answer 15

-large alterations within the DNA sequence in chromosomes
Inversions:
-inversion of a large segment of DNA
Fusions:
-rearrangement of chromosomal DNA by deletion, duplication, insertion or transposition

Question 16

Human vs. Chimp genome

Answer 16

• SNPs=1%
• approx 5 million short insertions/deletions a few BP each
• approx 40-45million BP difference total, approx 4% total difference between human and chimp genomes

Question 17

Outgroups

Answer 17

• compare SNPs for two different species (ie. Human, chimp)
• determine outgroup that diverged prior to the two species common ancestor (ie. orangutan) by comparing the SNPs from the three species

Question 18

Components that make up a genome

Answer 18

• coding sequences for RNA and protein mlc
• signals for chromatin condensation/chromatin remodelling
• Signals for initiation of replication and chromosomal integrity
• Control signals for on/off, levels of expression
• Start and stop sites for transcription
• Processing signals for primary transcripts
• Control signals for dynamic access at right time and place
• Identifiers for coding sequences that must be coordinately or sequentially expressed