biotech quiz 1

Artificial selection

Humans breed for traits, such as in dogs or corn.

Genetic engineering

Direct DNA change, examples include insulin in E. coli and Golden Rice.

Key difference between artificial selection and genetic engineering

Artificial selection is slow and uses existing traits, while genetic engineering is fast, precise, and can add new genes.

Downside of artificial selection

Can lead to inbreeding and decreased genetic diversity.

Downside of genetic engineering

May result in off-target effects, ethical concerns, and ecological risks.

Dogs vs insulin: which method?

Dogs are produced by artificial selection; insulin is produced by genetic engineering.

Ancient biotechnology: fermentation

Biotechnology methods such as fermentation for producing bread, beer, and yogurt.

Ancient crop/animal biotechnology

Involves selective breeding and domestication.

Ancient plant technique

Grafting fruit trees to combine desirable traits.

Four fields of biotechnology

Medical, agricultural, industrial, and environmental.

Medical biotechnology example

Insulin, vaccines, and gene therapy.

Agricultural biotechnology example

Bt corn and herbicide-tolerant soy.

Industrial biotechnology example

Enzymes, antibiotics, and biofuels.

Environmental biotechnology example

Bioremediation for situations like oil spills and wastewater management.

Restriction enzyme

A bacterial protein that cuts DNA at specific sites.

Recognition site for restriction enzymes

A short DNA sequence that is often a palindrome, such as GAATTC.

Sticky vs blunt ends in DNA

Sticky ends have overhangs that make joining easier, while blunt ends have flat cuts that are harder to join.

EcoRI cutting site

Cuts DNA at GAATTC, producing sticky ends.

Type of restriction enzyme commonly used in labs

Type II enzymes are used because of their predictable cut sites.

DNA ligase

An enzyme that 'glues' DNA together and seals its backbone.

Lab ligase and its energy source

T4 ligase uses ATP as its energy source.

How to improve ligation efficiency

Use sticky ends, higher DNA concentrations, and perform overnight reactions at low temperatures.

Plasmid

A small circular DNA molecule that replicates independently.

Why plasmids are useful

For gene cloning, protein production, and as delivery vectors.

Selectable marker in plasmids

Allows certain cells to survive, such as ampicillin resistance.

MCS/polylinker

A cluster of restriction sites that facilitates easy DNA insertion.

Cloning vector vs expression vector

Cloning vectors are used to store DNA, while expression vectors are used to produce proteins.

Copy number of plasmids

Refers to the number of plasmid copies per cell; a high copy number means lots of DNA, while a low copy number is more stable.

Steps of the cloning workflow

Cut DNA, ligate into a plasmid, transform into bacteria, select, and screen.

Blue-white screening

A method where blue indicates no insert and white indicates the presence of an insert.

Methods to confirm a clone

PCR, restriction enzyme digestion, and sequencing.

Why dephosphorylate a vector

To prevent self-ligation and ensure the insert is included.