Molecular Markers

Question 1

What is measured using molecular markers?

Answer 1

Genetic diversity.

Question 2

What is genetic diversity?

Answer 2

The variety of alleles and genotypes in the study group.

Question 3

What DNA is used for barcoding animals?

Answer 3

mtDNA.

Question 4

What DNA is used for barcoding plants?

Answer 4

cpDNA.

Question 5

What are the 3 steps and conditions of PCR?

Answer 5

1) Denaturation: DNA heated to 95°C and double DNA strand separates.
2) Annealing: DNA cooled to 55°C and primers bind to DNA template.
3) Extension: polymerase adds bases to complementary. 2 identical template copies formed.

Question 6

What are the advantages of using mtDNA in DNA barcoding?

Answer 6

It is easy to amplify and isolate.

Good for evolutionary studies as it evolves around 10X faster than the nuclear genome.

Question 7

What are the disadvantages of using mtDNA in DNA barcoding?

Answer 7

Only informative for maternal dispersal and evolution.
Copies are found in the chromosomes.
Heteroplasmy in different tissues (rare).

Question 8

Define heteroplasmy.

Answer 8

The presence of more than one type of organellar genome (mitochondrial DNA or plastid DNA) within a cell or individual.

Question 9

What are the advantages of using nuclear DNA in DNA barcoding?

Answer 9

Highly variable bands in a barcode.
Many genomic locations assessed at the same time.
No prior knowledge of genome required.

Question 10

What are the disadvantages of using nuclear DNA in DNA barcoding?

Answer 10

Cannot identify individual loci or inheritance type.
Unable to use non-invasive sampling - high quality DNA needed.
Now replaced by PCR-based fingerprinting.