SNP

Question 1

what is SNP?

Answer 1

single nucleotide polymorphisms - a site in a genome where a single nucleotide is polymorphic among different individuals

Question 2

what does it mean for a single nucleotide to be polymorphic?

Answer 2

it means there is a change in a single nucleotide

Question 3

SNPs are the smallest kind of change that can occur within a given gene

Answer 3

true

Question 4

SNPs are the most common genetic change

Answer 4

true

Question 5

SNPs represent ____ % of all the variation in DNA sequences that occur among different people

Answer 5

90%

Question 6

how many SNPS would occur in a gene that is about 2000-3000 bp in length?

Answer 6

10 polymorphic sites

Question 7

The high frequency of SNPs in genes indicate that polymorphism is the norm for most human genes

Answer 7

true

Question 8

A DNA locus that has two or more sequence variations , each present at the frequency of 1% or more in a population

Answer 8

polymorphism

Question 9

monomorphic

Answer 9

locus is 99% of individuals in a population

Question 10

what is a common frequency in most species for polymorphisms?

Answer 10

1 in 700

Question 11

about how many loci are in humans?

Answer 11

less than 1 million, or around 1 in 3000

Question 12

what are some types of polymorphisms?

Answer 12

SNPs, VNTR, deletions, duplications

Question 13

what is VNTR?

Answer 13

veritable number tandem repeats - includes micro satellites (short tandem sequences - STR) and mini satellites (long sequence repeated)

Question 14

what is the frequency of STR / microsatellites

Answer 14

• repeat is about 1-6 bp long
• the whole tandem repeats is less than a couple bp in length
• found about every 1000 bp in the human genome

Question 15

why do micro satellites tend to be hotspots for mutation?

Answer 15

alterations in the sequences of micro satellites oftentimes escape proofreading of DNA polymerase, so there could easily be a mutation in the number of repeats

Question 16

what is the frequency of mini satellite

Answer 16

• repeat is about 6-80 bo long

- size of the micro satellite is about 1-20 kip

Question 17

why are repetitive sequences useful?

Answer 17

• they are used as molecular markers (especially micro satellites) to map the location of genes
• also useful for studying variation among populations

Question 18

how does VNTR relate to identification?

Answer 18

VNTRs show variations in length and can be found on many chromosomes, where each variation acts as an inherited alleles allowing use for identification

Question 19

what are some uses of VNTR?

Answer 19

genetics, biology research, forensics, fingerprinting

Question 20

when do STRs (short tandem repeats) occur?

Answer 20

when a pattern of two or more nucleotides are repeated and the repeats sequences are next to each other
- pattern ranges from 2-10

Question 21

where in the genome do STRs occur?

Answer 21

usually in non-coding intron region

Question 22

what creates a unique genetic profile?

Answer 22

the number of STR repeats at a given locus

Question 23

what is the prevalent method for determining genetic profiles in forensic cases?

Answer 23

STR

Question 24

what are some applications of VNTR and STR?

Answer 24

• forensics
• 13 specific STR loci as the standard for CODIS in FBI
• mass disasters
• paternity testing
• military DNA dog tag
• convicted felon database
• genetic testing/gene mapping
• bone marrow transplant follow up

Question 25

what are some characteristics of polymorphisms?

Answer 25

- usually not on a coding region of genome - must associate specific fragment with disease or trait - many times linked to a disease but NOT the cause of the trait - problem?

Question 26

Single nucleotide substitution (SNS)

Answer 26

one nucleotides is replaced by another

Question 27

what are some forms of genetic variations?

Answer 27

SNS micro/mini sattelties deletions/insertaions changes in chromosomes number, segmental rearrangements and deletions

Question 28

SNPs appear at least once per ____ average intervals

Answer 28

0.3-1-kb average intervals

Question 29

for it to be an SNP, it must occur in at least ____ % of the population

Answer 29

1%

Question 30

the total number of SNPs is around ___ to ___ million

Answer 30

5-10

Question 31

SNPs occur every ___ to ____ bases in human genome

Answer 31

300-1000 bases

Question 32

two of every three SNPs involve the replacement of ____ with ____

Answer 32

cytosine with thymine

Question 33

SNPs occur in both coding genes and noncoding regions of the genome

Answer 33

true

Question 34

many SNPs have no effect on cell function

Answer 34

true

Question 35

SNPs can still predispose people to disease or influence repose to drugs

Answer 35

true

Question 36

SNP haplotype

Answer 36

A set of closely linked genetic markers present on one chromosome which tend to be inherited together (not easily separable by recombination) - haplotype has the advantage in carrying more information about gents-phenotype

Question 37

SNPs in coding regions may ____ the protein structure made by that coding region

Answer 37

alter

Question 38

DNA Chips Can Detect SNP Genotypes | (Or Haplotypes) Across An Individuals Genome

Answer 38

Millions of DNA sequences are on this chip. Same idea as mapping stars. Pin points/data points, same technology they used.

Question 39

what are the probes in the DNA chip?

Answer 39

tethered nucleic acids with known sequence

Question 40

what are the targets in DNA chip?

Answer 40

free nucleic acid sample whose purpose is being detected, where the labeled nucleic acid that is washed over the chip