Manipulating Genomes

Question 1

What is DNA sequencing?

Answer 1

Determines the exact order of nucleotides within a DNA molecules

Question 2

What is Sanger sequencing?

Answer 2

A method involving radioactive labelling of bases and gel electrophoresis

Question 3

What role do computers play in DNA sequencing, and what is next generation sequencing?

Answer 3

• Computers are able to reassemble genomes by comparing and overlapping DNA fragments
• Next gen sequencing involves all automated, high throughput DNA sequencing technologies
• This automation can help to speed up sequencing projects and reduce costs

Question 4

Define bioinformatics and - computational biology

Answer 4

• Bioinformatics - developing software and computational tools for collecting, storing, and analysing biological data
• Computational bio - uses this data to build theoretical models of biological systems, which can be used to predict what will happen in different circumstances

Question 5

How are bioinformatics databases useful in evolutionary biology?

Answer 5

• Researchers can find similarities between new DNA sequences and those already in databases
• This indicates common ancestry and allows scientists to build evolutionary trees with greater accuracy

Question 6

What is genomics?

Answer 6

The study of genomes, using DNA sequencing and computational biology to analyse data like base pairs in DNA, protein structures, and gene regulation

Question 7

How does genomics help in managing infectious disease?

Answer 7

Pathogen genome sequencing and analysis helps to -
- identify sources of infection
- identify antibiotic resistant strains
- aid in drug and vaccine development
- monitor outbreaks and plan treatments more effectively

Question 8

What is proteomics?

Answer 8

• The study of an organism’s entire set of proteins produced by the genome (the proteome), including their structure and function

Question 9

What is synthetic biology, and what are some of its potential benefits?

Answer 9

• Involves designing and constructing new biological systems or redesigning existing ones
• Can be used to synthesise functional genes to replace faulty ones as treatments for genetic disorders
• And using biological systems and microorganisms to produce drugs efficiently and cheaply

Question 10

What are variable number tandem repeats and short tandem repeats?

Answer 10

• VNTR’s (aka minisatellites) are unique sequences of non coding DNA/introns that vary between individuals
• STR’s (aka microsatellites) are repeated sequences of nucleotides that are smaller than VNTR’s
• Both of them can be used in DNA profiling/fingerprinting as their length and location are heritable and fairly unique to individuals

Question 11

What is PCR and the basic components required for it?

Answer 11

Method for amplifying DNA fragments rapidly and efficiently
Requires -
- DNA fragment to act as a template
- Primers
- DNA polymerase (taq polymerase)
- Free nucleotides
- A thermocycler

Question 12

What are primers?

Answer 12

Short nucleotide sequences that bind to complementary DNA strands, initiating replication

Question 13

What is the purpose of the buffer solution used in electrophoresis?

Answer 13

Provides a constant, suitable pH

Question 14

Other than DNA, what other molecules can be used in electrophoresis, and what are the uses of this?

Answer 14

• RNA and proteins can also be separated using electrophoresis
• To identify proteins in samples like urine or blood, aiding in disease diagnosis

Question 15

What technique is used after gel electrophoresis to better visualise the separated DNA strands?

Answer 15

Southern blotting transfers single-stranded DNA to a membrane for analysis

Question 16

What are restriction endonucleases?

Answer 16

Enzymes derived from bacteria that cut DNA into fragments at specific restriction sites

Question 17

What are sticky ends in DNA?

Answer 17

• Short, overhanging sequences of unpaired bases at the end of a DNA fragment cut by restriction enzymes
• They are used to insert genes into vectors

Question 18

What is the role of DNA ligase in forming recombinant DNA?

Answer 18

• Forms phosphodiester bonds between sugar and phosphate groups on the two strands of DNA
• This joins the sticky ends of the isolated DNA fragment to the sticky ends of the DNA in the plasmid vector

Question 19

What is electroporation?

Answer 19

• A method of transformation during which an electrical current makes bacterial membranes porous
• This allows the plasmids to move into bacterial cells

Question 20

What are some concerns regarding genetically engineered pathogens?

Answer 20

• Risk of accidental infections and disease outbreaks
• Risk of engineered pathogens reverting to their harmful form

Question 21

What is pharming?

Answer 21

The production of human medicines by introducing human genes into animals

Question 21

What are the concerns with patenting and technology transfer in GM crops?

Answer 21

Can restrict access for farmers in developing countries due to legal and cost barriers

Question 22

What is somatic cell gene therapy?

Answer 22

• Replaces mutant alleles with healthy alleles in affected somatic (body) cells to treat diseases
• Somatic cells have a limited lifespan and are replaced by stem cells with the original faulty allele

Question 23

What is germ line cell gene therapy?

Answer 23

• Involves inserting a healthy allele into germ cells or embryos to prevent genetic diseases from birth