CSI Wildlife (Gel Electrophoresis)

Question 1

How is DNA fingerprinting used to study elephants?

Answer 1

The results of the DNA fingerprinting is matched to the suspected elephant’s DNA.

Question 2

How can the information obtained from DNA fingerprinting help save elephants?

Answer 2

Information from DNA fingerprinting reveals the individual elephant and its location, therefore certain measures can be increased in that area in order to reduce ivory poaching.

Question 3

what does str stand for

Answer 3

short tandem repeats,string of nucleotide units that repeats
ex
GATA segment
GATAGATAGATAGATA

Question 4

STRs at specific loci have shared characteristics between individuals and/or alleles. Highlight the characteristic(s) that are
shared.

Answer 4

Made up of nucleotides Flanking sequence unit, i.e., CTA

Question 5

List three sources to obtain elephant DNA for analysis:

Answer 5

Hair roots, saliva, or body tissue

Question 6

Why are flanking sequences important for amplifying STR fragments?

Answer 6

Flanking sequences are essential for amplifying STR fragments because it makes the enzymes initiate the copy process for STR fragments.

Question 7

Scientists typically amplify multiple STR fragments from an individual in a single PCR. Explain how they can do that.

Answer 7

They use PCR to amplify STR fragments by using primers that are complementary to portions of the flanking sequences to make sure that the region in between are also amplified. This all leads to the amplification of multiple STR fragments in one PCR.

Question 8

What is the relationship between the size of a DNA fragment and the distance it migrates in the gel?

Answer 8

The longer a DNA fragment, the farther it is from the end of the gel.

Question 9

how do u know if an elephant is homozygous or heterozygous based on their gel

Answer 9

2 bands would= heterozygous

Question 10

What do the bands represent?

Answer 10

DNA fragments that are versions of short tandem repeats (STR)

Question 11

What is a DNA ladder used for? What are they measured in

Answer 11

• A DNA ladder is used as a reference for determining STR sizes.
• They are measured in base pairs (bp)

Question 12

What is a DNA ladder?

Answer 12

A mixture of dna fragments of known lengths that allows you to work out the length of the bands in genetic fingerprints.

Question 13

What is the flanking sequence?

Answer 13

The extension on either side of a specific gene

Question 14

What does a marker represent?

Answer 14

A gene

Question 15

What is allele frequency?

Answer 15

The number of times an allele occurs in a gene

Question 16

1st step of dna profiling?

Answer 16

collect dna sample, any material containing cells

Question 17

2nd step?

Answer 17

extract dna by chemicals, seperated from other cells components

Question 18

3rd step?

Answer 18

amplify strr fragments
involves pcr (polyamerse chain reaction to make copies of <13 different STR regions,

using primers which flank the region binding on each side of the DNA.
TTTTTTTTTTT primers
⊥⊥⊥⊥⊥⊥⊥ <–template DNA

Question 19

what is pcr

Answer 19

To amplify a segment of DNA using PCR, (1) denaturation of the template into single strands by heat; (2) annealing of primers to each original strand for new strand synthesis; and (3) extension of the new DNA strands from the primers.

Question 20

4th sptep?

Answer 20

determine length of strs

seperated by gel electrophoresis
larger fragments, more str repeats, small fragments, less repeats

Question 21

5th

Answer 21

interpret data
patterns of bands on the electrphohoh gel creates a DNA profile

Question 22

whats gel electrophoresis

Answer 22

is a technique used to separate DNA fragments according to their size.DNA samples are loaded into wells (indentations) at one end of a gel, and an electric current is applied to pull them through the gel. DNA fragments are negatively charged, so they move towards the positive electrode.