Biotechnology Bio exam 4

What is recombinant DNA?

Process of splicing together DNA from different organisms,
to obtain many copies of a DNA segment for
research

  What is a plasmid?

circular bacterial DNA

How are plasmids important in recombinant DNA?

They serve as vectors to introduce foreign DNA into bacterial cells

What is transformation in general?

The successful uptake of foreign DNA

What are some examples of transformation?

• E. coli has been transformed with human
  gene for insulin and is now the source of
  human insulin for diabetics

• E. coli has been transformed with human
  gene for interferon is now the source of
  interferon used to treat some viral
  infections, like Hepatitis C.

 What is antibiotic resistance in bacteria?

A condition where bacteria evolve to survive exposure to antibiotics, often due to genetic changes

How can it spread between bacteria?

This can be spread by transformation via
plasmids or through conjugation and transduction.

What happens in transformation?

Bacteria picks up pieces of DNA or
plasmids from the environment, and
incorporate this into their genome

What happens in transduction?

Genes are
transferred accidentally by a
bacteriophage (a virus that
attacks bacteria)

What happens in conjugation?

• A plasmid is passed through a sex pilus

• F+ cell transfers a copy of the plasmid
  with a gene for making a sex pilus to an
  F- cell; both are F+ when finished

What associates with conjugation?

Bacterial sex

Where is conjugation common?

Common in the Gram negative gut
bacteria

Sex pilus -

used by bacteria during conjugation to transfer genetic material

Bacteriophage -

a virus that infects and replicates within bacteria

What is a genome?

The total DNA in a cell

Where are most of our genes found?

Most of our genes are found in the nucleus of eukaryotic cells

Where else do we have genes?

mitochondria and chloroplasts

How about plants? 

Plants have genes in their nuclei, chloroplasts, and mitochondria.

Bacteria?

Bacteria have genes in their nucleoid region

What is happening in electrophoresis?

Electrophoresis is a technique used to separate charged particles, such as DNA or proteins, by applying an electric field

What kind of charge is on DNA?  Proteins? in electrophoresis

DNA is negative

Proteins are positive or negative depending on their amino acid composition

What pole do they move toward? 

positive pole

Why do some molecules move faster than others?

Smaller parts move faster through the gel

Be able to list four different things that DNA Fingerprinting is used for

• Analyzing evidence found at crime scenes

• Identifying mass disaster victims

• Clarifying parental disputes

• Identifying human cancer cells

 What organism did Stuart work with?

• Carrot (plant cells)

 What organism did Gurdon work with?

• Frog (animal cells)

What did both of them demonstrate?

They demonstrated that differentiated cells can be reprogrammed to become pluripotent stem cells

  What two kinds of cells did Wilmut use to clone sheep?

Adult sheep cell & an un-nucleated egg

How did he get the cells to fuse?

He used an electric current to induce fusion

  Some of the lambs did not always live long.  Explain why using telomeres in your discussion

if the cloned lambs' donor cells had shorter telomeres, it could lead to premature aging and health issues, causing them to not live long

 What are stem cells in general?

Undifferentiated cells that can divide to
produce any differentiated cells within an
organism

Totipotent stem cells -

• from zygote

• can develop to all
  body cell types and placenta

Pluripotent stem cells -

• from embryonic & adult

• give rise to many, but not all, cell types

What’s a zygote?

A zygote is the first cell formed when a sperm and egg fuse during fertilization

What is apoptosis?

programmed cell death

Give an example of apoptosis in humans.

• hand forms as a webbed structure then
  fingers separate as cells between them die

 Proto-oncogenes -

normal genes which
mutate to become oncogenes

Oncogenes -

cancer-causing genes that
cause cells to grow and divide
uncontrollably

Tumor suppressor genes

growth inhibiting
factors that block cell division, providing
normal controlled cell growth

List some mutagens that may trigger cancer

• Dietary fat

• Benzopyrene

• Nitrosamines

Hyperplasia -

an increase in the number of cells within a tissue or organ

Anaplasia -

a condition where cells lose their differentiation and organization

Metastasis -

the spread of cancer cells from the original tumor to distant parts of the body

Initiator - EX:

cause mutations / cancerous
cells to form

EX:
• Benzopyrenes, Nitrosamines

Promoter - EX:

cause cancerous cells to
grow

EX:
• Dietary fats, especially saturated fats

Antipromoter - EX:

protect against cancerous
cells from forming
EX:
• Lycopenes, Anthocyanins, Cruciferous
Vegetables

 List four things that you could eat that would may help protect you from developing cancer

• Fruits

• Vegetables

• whole grains

• legumes

 Why are high amounts of a fat in the diet bad for cancer?

promoting obesity, which is a major risk factor for many cancers