Biotechnology

Question 1

Define biotechnology.

Answer 1

Application of biological knowledge to the production of organisms (or products) useful to mankind

Question 2

What is recombinant DNA?

Answer 2

rDNA molecules are DNA molecules formed by laboratory methods of genetic recombination

Question 3

What is a nuclease?

Answer 3

Restriction enzyme that cleaves DNA at or near specific recognition sites

Question 4

Differentiate between endonuclease and exonuclease

Answer 4

Endonuclease (within) - break nucleic acid strands within interior of molecule

Exonuclease (outer) - break strands at ends of molecule

Question 5

What are sticky ends?

Answer 5

fragments of unpaired DNA bases formed when particular base sequences are cut asymmetrically

Question 6

What is DNA ligation?

Answer 6

DNA ligase is an enzyme which can connect 2 strands of DNA together by forming bond between phosphate group of one strand and deoxyribose group of another

Question 7

What occurs during homologous recombination?

Answer 7

Nucleotide sequences exchanged between 2 similar or identical molecules of double-stranded or single-stranded nucleic acids, used to repair harmful breaks, produces new combinations of DNA sequences during meiosis (new combinations represent genetic variation)

Question 8

What occurs during non-homologous end joining?

Answer 8

repairs double-strand breaks in DNA

Because there is no “donor template”, it is subject to many errors regarding insertions and deletions

Question 9

Describe reverse transcription.

Answer 9

goes from mRNA to DNA
Prokaryotes have no introns (non-coding DNA), therefore eukaryotes need introns to be removed from DNA so mRNA can produce functional proteins

Question 10

Draw a diagram to represent reverse transcription.

Answer 10

mature mRNA (no introns) ——-> DNA version of mRNA——-> complementary DNA strand (no introns)——> plasmid (circular sections of DNA (prokaryotes))

1st arrow - reverse transcriptase
2nd arrow - DNA polymerase

Question 11

What is the purpose of polymerase chain reaction (PCR)?

Answer 11

to amplify a specific region of genome (usually single gene)

Question 12

How is PCR conducted?

Answer 12

Rapid heating and cooling, in presence of DNA primers (short, single, strand nucleotides)

Question 13

What are applications of PCR?

Answer 13

making recombinant DNA
forensic identification and paternity testing
diagnosing disease
determining whether particular gene is expressed in specific tissues/ under specific conditions
quantifying DNA or RNA in sample

Question 14

What does gel electrophoresis do?

Answer 14

Duplicates of DNA from PCR are used to identify differences in organisms/individuals

Question 15

Describe steps of gel electrophoresis.

Answer 15

1. Cut DNA samples with same restriction enzyme
2. Load samples onto gel sheet
3. Pass current of electricity through gel. Small pieces of DNA more faster and further than longer pieces.
4. Results show “restriction fragment length polymorphism” and can be visualised under UV light

Question 16

What is the purpose of DNA sequencing?

Answer 16

To determine precise sequence of individual nucleotides of an organism/person

Question 17

Why is DNA sequencing important?

Answer 17

Genes need to be known before genetic engineering. It is also inly possible to make recombinant DNA once the genes are known. This knowledge is gained through DNA sequencing.

Question 18

What are bioinformatics?

Answer 18

studies that use computers and programs to assist with collecting, classifying, storing and analysing biochemical/biological information