Genetics Today

Question 1

The human genome project

Answer 1

1990-2003
Aims- sequence all 3.3 billion bases, identity all 20500 genes (gene maps), sequencing tools and put info in database, transfer to private sector, ethics (gen info nondiscrimination act) and compare by sequencing others species

Question 2

Results of Human Genome Project

Answer 2

• avg gene is 3000 bases
• 20000-25000 total genes
• <2% code for proteins
• 50% gene functions unknown
• repeated sequences make up 50%
• humans have same protein families as other species but # gene family members greater in humans for dev and immunity
• humans have 3x more proteins b/c splicing

Question 3

Transitions

Answer 3

Change purine for another purine (AG) or pyrimidine for another pyrimidine

Question 4

Transversions

Answer 4

Substitute purine for pyrimidine

Question 5

Missense

Answer 5

Change single AA

Can be conservative (new AA is still basic or neutral) OR non-conservative (new AA is basic while original was neutral and vice versa)

Question 6

Nonsense

Answer 6

Insertion of stop codon - termination of protein synthesis

Question 7

RNA Splicing

Answer 7

Exon skipping (coding mutation)

Exon skipping/intron retention (non coding mutation)

Question 8

Regulatory Mutation

Answer 8

Changes in protein modifications

Question 9

Insertion

Answer 9

Change in reading frame

1 or 2 base pairs

Question 10

Deletion

Answer 10

Loss of function of protein

Question 11

Repeat expansion

Answer 11

Altered structure of protein (coding mutation)

Altered expression (noncoding mutation)

Question 12

Promoter

Answer 12

Transcription is altered –> inc or dec in protein levels

Question 13

SNP

Answer 13

Single nucleotide polymorphism

Single base difference (1 in every 1000/1500 base pairs)

Make up 90% genetic variation

Caused by sub/deletion/insert of 1 base

Question 14

Halpotype

Answer 14

Linear array of consecutive SNPs that define a particular chromosomal region

Question 15

HapMap

Answer 15

Project to develop a map of human variants (chromosomal regions and genes associated w disease and response to drugs)

Mapped 1 million SNPs to find types of variation, where they occur and distribution among races/populations

Ancestry.com uses your individual HapMap

Question 16

1000 Genomes Project

Answer 16

Std for population genetics and genomics research

2008-2015

Identified 99% of SNPs that occur in >1% of population by sequencing 2500 people from 26 populations

Question 17

Typical Human Gene

Answer 17

mRNA is exons w/o introns; exons joined via splicing signals

First exon contains non-coding 5’ UTR (untranslated region) then coding region that starts w/ AUG

Last exon contains 3’ UTR

Question 18

Classification of Genetic Disease

Answer 18

1- monogenic (mendelian- one gene involved)
2- polygenic/multifactorial inheritance (combo of genes)
3- chromosomal (gross changes in chromosome structure itself)