DNA sequence and profiling

Question 1

What is Dna sequencing?

Answer 1

The practice of isolating DNA to identify sequential order of nucleotides present.

Determines the precise order of nucleotides in a dna segment

Provides information about composition and location of different genes in a chromosome

Can be used to determine genetic differences and inheritance patterns within population

Question 2

What is PCR (polymerase chain reaction)?

Answer 2

a technique used to exponentially amplify large numbers of copies of a specific dna sequence

Question 3

What is the process of PCR?

Answer 3

Process:
Denaturation
Dna sample is heated to separate it into 2 single strands at 95 degrees

Annealing
Dna primers attaches to 3’ ends of target sequence (55 degrees)

Elongation
Dna polymerase binds to primer + copies strand of dna (72 degrees) and repeat 30 times

Question 4

What is DNA profiling?

Answer 4

Dna profiling is the analysis of unique patterns of DNA sequences in a genome to identify individuals, this allows a comparison of certain sequences.

Question 5

What is STR?

Answer 5

STR (short tandem repeats)
Genetic marker - sequence of repeating bases eg, ACG CCA CCA TTA CAC TTA
Measures how many repeats there are at a specific position on chromosomes

Question 6

Outline the process of Gel electrophoresis

Answer 6

The process of Gel electrophoresis:

Acquire individual’s dna eg, blood, hair and skin

Dna are cut into fragments using restriction enzyme

Create mixture of different fragments sizes

Replicate fragments using PCR (polymerase chain reaction)

Place dna fragments in electrophoresis gel

Run electrical current through electrophoresis gel