Lec 15 (ancient DNA)

Question 1

What main things are we interested in in population genetics?

Answer 1

1. SNP
2. how many people in a pop have that specific SNP
3. allele frequency
4. frequency change over time = changes are due to the environment

Question 2

What does LP stand for

Answer 2

lactase persistence

Question 3

What are the key definitions used in population genetics

Answer 3

3

1. ancient DNA
2. Gene frequency
3. Allele frequency

Question 4

Define population genetics

Answer 4

it is the study of changes in the genetic composition of a population that occur over time and under evolutionary pressures

Question 5

population genetics extended the principles of ____ and ___

Answer 5

Gregor Mendel and Charles Darwin

Question 6

What does LNP stand for? aka __

Answer 6

Lactase non-persistence

lactose intolerance

Question 7

Population genetics studies the transmission of ___

Answer 7

Population genetics studies the transmission of genetic variation in populations

Question 8

Hypoxia gene in south America provide an adaptation to survive ____

Answer 8

Hypoxia gene in south America provide an adaptation to survive in high altitudes

Question 9

Define population

Answer 9

A group of interbreeding individuals of the same species that inhabit the same space at the same time and share a gene pool

Question 10

Define gene pool

Answer 10

Sum of the alleles carries by all members of a population

Question 11

square = male/female

Answer 11

male

Question 12

What is a SNP?

Answer 12

a Single nucleotide polymorphism

A single nucleotide locus with 2 naturally existing alleles defined by a single base pair substitution

Question 13

SNPs make up around __% of all human genetic variation

Answer 13

90%

Question 14

__ are the most frequenct genetic variant

Answer 14

SNPs

Question 15

What must occur in at least 1% of the population to be considered a ___

Answer 15

SNP

Question 16

In the paper published in 2014, a SNP had been identified. What was this and where?

Answer 16

SNP was a change from a C (cytosine) to a T Thymine) at position -13910.

Question 17

What does it mean to have an autosomal dominant trait?

Answer 17

You only need one copy of the trait to display it

Question 18

Briefly describe the genetics of Lactase persistence

Answer 18

1. autosomal dominant trait
2. enabling life-long digestion of lactose (milk sugar)
3. Ezy = lactase-phlorizin hydrolase (LPH)
4. lactase persists into adult life in some, but not all. people
5. common genetic trait in many European. African and Middle Eastern Populations

Question 19

What does LPH stand for and what is it?

Answer 19

LPH= lactase-phlorizin hydrolase

the enzyme for lactase persistence

Question 20

What is a possible reason as to why LP is a common trait in european, African and Middle Eastern Populatoins

Answer 20

The selection may be due to one of the nutrients or water in fresh milk and/or its calorific value

Question 21

What is the reaction for the breakdown of lactose

Answer 21

Lactose (disaccharide sugar)

Lactose + H2O ==(lactase)==> galactose + glucose

which can then be absorbed by the small intestine

Question 22

In terms of the breakdown of lactose, what occurs in lactose-intolerant individuals?

Answer 22

Lactose is not broken down into the monosaccharides, therefore, there is a build-up of lactose in the gut which results in bloating, abdominal pain and diarrhoea

Question 23

LPH ___ lactose into ____ for ___ in the __

Answer 23

LPH hydrolyses into galactose and glucose for absorption in the small intestine

Question 24

What is the LP in Europe

Answer 24

SNP that changes C to T

Question 25

downstream left/right

Answer 25

right

Question 26

Where is the SNP in relation to the lactase gene

Answer 26

If you have an enzyme that is encoded by a gene, you expect the SNP responsible for causing LP to be in the Lactase gene. However, the SNP is downstream of the lactase gene. The SNP interferes with regulation of the lactase gene.

Question 27

where are the SNPs located? give cytogenetic location

Answer 27

c/some 2 , long arm q, region2, band1, sub-band 3

2q21.3

around 132 SNPs along with region

Question 28

___ prevents down -regulation of lactase activity after weaning

Answer 28

SNP (T-13910)

it affects a binding site of transcription factor

Question 29

the gene that encodes lactase is __

Answer 29

LCT

encodes lactase (LPH)

Question 30

lactase persistence= expect the mutation to be in __

Answer 30

the LCT gene, however, it is further downstream in the gene MCM6 (minichromosome maintenance 6)

The SNPs are in the intron regions of this gene