chapter 6 - biotechnology

Question 1

Define DNA sequencing

Answer 1

The process of establishing the nucleotide sequence of a piece of DNA

Question 2

Define genome

Answer 2

All of the genetic material contained in an organism or a cell; includes the chromosomes within the nucleus and the DNA in mitochondria and chloroplasts

Question 3

Define genome mapping

Answer 3

Identifying and recording the relative positions of genes on a chromosome using genetic markers, linkage mapping and physical mapping

Question 4

Define DNA profiling

Answer 4

A process that is able to identify natural variations that exist within individual genomes using STRs, VNTRs, PCR and gel electrophoresis

Question 5

Define DNA profile

Question 6

Explain how DNA profiling identifies the unique genetic makeup of individuals

Answer 6

Within the non-coding regions of an individual’s genome, there exists satellite DNA (long stretches of DNA made up of STR’s and VNTR’s). Individuals are likely to have different numbers of STR’S and VNTR’s at a given satellite DNA locus, meaning they will generate unique DNA profiles.

Question 7

What is the purpose of PCR

Answer 7

PCR is a cyclic method used to rapidly replicate relatively small amounts of DNA into extremely large amounts

Question 8

What is the purpose of gel electrophoresis

Answer 8

A technique that separates large molecules (either fragments of DNA or proteins) according to their size and charge, for visualisation and identification purposes.

Question 9

What is the purpose of DNA transformation

Answer 9

DNA transformation allows bacteria to take in DNA fragments from their environment and incorporate them into their own genome

Question 10

What is the purpose of gene cloning using plasmids

Answer 10

Allows for the replication of larger segments of DNA and permits the analysis of any gene (and its associated proteins)

Question 11

Explain how restriction enzymes work

Answer 11

Restriction enzymes splice the two strands of DNA at a recognition site to form sticky (overhanging string of nucleotides, specific to various restriction enzymes) ends or blunt (no overhang, clean cut and non-specific) ends

Question 12

Explain how ligation works

Answer 12

DNA ligases performs ligation by rejoining the phosphate bonds that make up the sugar phosphate backbone between the separated portions of DNA, then nitrogenous bases anneal weak hydrogen bonds