Bio Technology Unit Test

Some ways we can use DNA

• Identify individuals 

  • Criminals

  • Family Members

• Alter the DNA code of organisms

  • Crops

  • Humans

  • Bacteria 

• Create medicines

Genetic Engineering

is the process of modifying an organism's DNA to introduce new, desirable traits.

The steps in which scientists can make changes to DNA

• Extract DNA from cells

• Cut DNA into smaller pieces 

• Make unlimited copies of DNA

• Analyze identify the sequence of bases in a DNA molecule

What are used to cut specific sequences of DNA?

Restriction Enzymes

What do Restriction Enzymes do?

Recognize specific sequences called palindromes to cut

Sticky End Cut

A cut through the sugar phosphate backbone and through the hydrogen bonds. It creates a tail or  a complementary overhangs. The overhangs can be paired with their compliments

Blunt End Cut

A cut through the sugar phosphate backbone only

Polymerase Chain Reactions

Technique that allows biologists to make copies of DNA.

Uses for PCR

• Small Amounts of DNA can be multiplied, allowing more tests to be done.

• Can be performed with a Thermal Cycler

• Used in crime labs

Thermal Cycler

Machine that can cycle between temperatures

Steps of PCR

1. Denaturing

2. Annealing

3. Extending

Denaturing in PCR

DNA is heated to 94℃ to unwind the DNA

Annealing in PCR

DNA is then cooled to 55 ℃ to allow the DNA primers to bind to the unwound DNA

Extending in PCR

DNA is then heated to 74℃ so the Polymerase can create the new strands of DNA

What is the original method of Gel Electrophoresis?

Restriction enzymes recognize and make cuts within a specific palindromic sequence or restriction site.

What are DNA fragments poured into in Gel Electrophoresis?

Wells on a gel

What is applied to the gel during Gel Electrophoresis?

An electric charge

DNA has a ________ charge

negative

Because of it’s charge, DNA will travel from _ to _ in Gel Electrophoresis

- to +

The _______ the DNA fragment, the ______ and _______ it will move across the gel

smaller, faster, and farther

Short Tandem Repeat Analysis

A method used to compare allele repeats at specific locations in DNA between two or more samples.

TRUE OR FALSE: Repeats code for a specific trait

FALSE

TRUE OR FALSE: Repeats in the DNA are unique to each person

TRUE

What does STR use to produce many copies of specific STR sequences

PCR

Why is PCR helpful for STR?

It makes it easier to identify the STR sequence

What show the specific location of repeats in STR?

Gel Bands

Is cutting necessary in STR?

No

Do identical twins have the same DNA fingerprint?

Yes

What does DNA fingerprinting do?

It analyzes sections of DNA that vary widely between individuals

Where can DNA samples can be obtained from?

Blood and hair strands with tissue at the base

What did squashing the strawberry do in the strawberry lab?

Broke open the cell walls and got to the DNA

What did using an extraction buffer in the strawberry lab do?

Helped break down the cell walls and nucleus to release the DNA into the solution

What did pouring the mixture through filter paper do in the strawberry lab?

It filtered out the bits that were not wanted, like the broken up cell wall

What did adding cold rubbing alcohol do in the strawberry lab?

It made sure the DNA didn’t dissolve in the water

What did the clumped up and extracted DNA look like?

Clouds or cotton/wool

How does a restriction enzyme help simplify the job of a scientist?

Instead of analyzing long strands of DNA, specific sections of DNA can be cut into smaller pieces

What is a recognition sequence?

A specific 6 letter sequence that only the restriction enzyme that is next to it will cut

Where do the names for restriction enzymes come from?

Where the restriction enzyme is originally from

Polyploidy

Having more than 2 sets of homologous chromosomes (you should know what those are by now)

Each different restriction enzyme as it’s own ___________ ____

Restriction Site

DNA Palindrome

A sequence in which the “top” strand read from the 5’ end of DNA to the 3’ end is the same as the “bottom” strand read from the 5’ end of DNA to the 3’ end

When scientists study a DNA molecule, one of the first things they do is to…

figure out where many restriction sites are

After finding out where restriction sites are, scientists…

then create a restriction map, showing the location of cleavage sites for many different enzymes. 

Knowledge of different restriction sites helped genetic researchers create…

Recombinant DNA

Recombinant DNA

DNA made by recombining fragments of DNA from different sources

What industries have been influenced by the creation of recombinant bacteria?

Medicine and Agriculture

In medicine, Recombinant DNA is used to…

Produce various hormones such as growth hormones and insulin

In agriculture, Recombinant DNA is used to

Prevent frost damage in some plants and help to convert atmospheric nitrogen to nitrates, a natural fertilizer used by plants

Why are DNA fingerprints unique and diverse (for non-twins)

DNA code is universal for all living things and that there are differences between individuals within that code

Gel Electrophoresis Tools

• electrophoresis chamber & power supply

• 1% agarose gel 

• 5 DNA samples 

• micropipettes and tips

How is Recombinant DNA created?

Using restriction enzymes, desired DNA is cut out of one organism’s genome and into incorporated the DNA of another organism that has been cut by the same restriction enzyme

Transgenic Cells

Cells that take in Recombinant DNA

Recombination in Bacteria

The SAME restriction enzyme is used to cut the selected Human DNA and the DNA in the bacterial cell

Plasmid

Circular DNA of bacteria

Recombination

The combination of two pieces of DNA

Transgenic Organisms are also called…

Chimeras

Bacteria is used to produce…

Insulin, Growth Hormones, and Clotting Factors

Transgenic Plants

Used to prolong the life of plants, increase size, protect against disease or promote growth in changing environmental conditions

Transgenic Animals

Animals that can be used to create environmentally friendly livestock or treat food allergies or produce more food

Examples of Transgenic Animals

Enviropigs and GalSafe Pigs

Enviropigs

Genetically engineered pig that produces feces and urine containing 65% less phosphorus than standard porkers (not yet approved by the FDA)

GalSafe Pigs

First in history to be approved for both food and therapeutics.  

Eukaryotic Transformation

• When a recombinant DNA is introduced outside of the cell, the cell can absorb the DNA.

• If there is a similar sequence, the recombinant DNA can “knock out” a gene from the host cell and replace that gene.

Gene Therapy

When an absent or faulty gene is a replaced by a normal gene

What happens after gene therapy?

Once the gene is replaced, the organism can start producing the right protein

Gene therapy IS OR IS NOT a permanent fix?

IS NOT

Why are virus particles modified in gene therapy?

So that they cannot cause disease

Why are virus particles used in gene therapy?

For their ability to infect cells

What happens after the host is infected by the virus in gene therapy?

The virus carries the gene into cells to correct genetic defects

Cloning

Genetic identical copy of a host organism.

What is the first step of cloning?

A donor diploid  body cell is taken from the cloning specimen

What is the second step of cloning?

An egg cell is taken from an adult female organism

What is the third step of cloning?

The nucleus from the egg cell is removed.

What is the fourth step of cloning?

The two cells are fused together through an electric shock to form a fused cell

What is the 5th step of cloning?

The embryo is placed in the uterus of a foster mother.

Benefits of cloning

Can revive extinct animals, can be used to grow organs

Why do some people disagree with reviving extinct animals with cloning?

Some people believe the clones may have genetic defects

Cloning being used to grow organs is…

highly controversial and relates to Bioethics

The Human Genome Project

• Research groups analyze the DNA sequence, looking for genes that provide clues to the basic properties of life.

• Biotechnology companies are looking for information that may help develop new drugs and treatments for diseases.

What does CRISPR stand for?

Clustered Regularly Interspaced Short Palindromic Repeats

What do CRISPR genes do?

They help completely replace an undesired sequence

CAS 9

focuses / targets on faulty DNA and attaches a guide RNA to replace the undesired protein

CAS 3

destroys sections of faulty DNA

Sherlock

focuses / targets faulty RNA and viral information

Selective Breeding

• The processes of allowing organism with desired characteristics to reproduce.

•  Takes advantage of the natural variation in nature

Hybridization in Animals

• Crossing two different species together and passing the best of both traits.

• Offspring is infertile (unable to reproduce)

Examples of Hybridization in plants

Cotton Candy Grapes and Pineberries

Inbreeding

• Continual breeding of individuals with similar characteristics.

• Can cause genetic disorders if individuals carry rare recessive genes

Examples of Inbreeding

The Fugates, Habsburg Jaw, White Tigers

The Fugates

Inbred family that were known to be carriers of methemoglobinemia causing their skin to be blue

Habsburg Jaw

A royal family possessed this trait due to inbreeding and recessive genes where the lower jaw outgrows the upper jaw resulting in an extended chin and a crossbite

White Tigers

Are the result of a natural variation in tigers due to a recessive gene

White Tigers often have problems such as…

Crossed eyes,  heart abnormalities, abnormal cranial structures and ‘Bulldog faces’

What cuts are made to the plasmid and human DNA

Sticky End Cuts

Somatic Nuclear Transfer

Uses somatic body cells, makes an exact copy of the organism, and transfers the nucleus from a somatic cell to an egg cell

Artificial Embryo Twinning

Method of cloning that mimics nature and uses a surrogate mother

Somatic Nuclear Transfer and Artificial Embryo Twinning both…

have fertilization occur

An egg cell is HAPLOID or DIPLOID?

HAPLOID

Why is the nucleus removed in cloning?

So the nucleus of the organism that is cloned can be inserted

What is is called when the nucleus is removed from the egg?

Ennucleation