Emerging Concepts and Biotechnology

Question 1

Biotechnology

Answer 1

The maniuplation of organisms or their components to make useful products

Question 2

What are the main techniques of biotechnology?

Answer 2

DNA sequencing, gene cloning, PCR amplification, gene editing

Question 3

Recombinant DNA

Answer 3

Nucleotide sequences from two different sources, are combined in vitro into the same DNA molecule

Question 4

Plasmid

Why is this used as a cloning vector?

Answer 4

Small circular DNA molecules that replicate separately from the bacterial chromosome

Plasmids are:
- readily obtained
- easily manipulated
- easily introduced into bacterial cells
- rapidly multiplied once in bacteria

Question 5

How is a gene cloned?

Answer 5

1. Gene of interest inserted into plasmid
2. Plasmid put into bacterial cell
3. Host cell grown in culture to form a clone of cells containing the “cloned” gene of interest
4. Research based on copies of gene or protein harvested

Question 6

How do we cut out genes to clone them?

Answer 6

Bacteria have evolved their immune system and produced an enzyme known as a restriction enzyme.

Restriction enzymes cut DNA molecules at restriction sites. The most useful restriction enzymes cut DNA in a staggered way, producing sticky ends.

Question 7

How are the sticky ends sealed?

Answer 7

DNA ligase seals them

Question 8

What is Cas9?

Answer 8

Cas9 is a RNA-guided DNA endonuclease that can be used to direct precise cutting of DNA sequences.

Question 9

How is the Crispr-Cas9 system used in genome editing?

Answer 9

1. Cas9 protein and guide RNA bind to each other
2. The complementary sequence of the guide RNA binds to the target gene
3. Cas9 protein cuts the DNA on both strands
4. The broken strands are repaired

Question 10

How was Dolly the sheep cloned?

Answer 10

1. A mammary cell was taken from one sheep
2. The nucleus was removed from the egg cell from the ovary of another sheep
3. The mammary cell was fused with the empty egg cell and then grown in culture
4. The early embryo was implanted in the uterus of a third sheep
5. Out came DOLLY, the clone of the mammary cell donor

Question 11

Stem cell

Embryonic vs. adult

Answer 11

A relatively unspecialized cell that can reproduce itself indefinitely and differentiate into specialized cells of one or more type.

Embryonic stem cells can differentiate into all cell types. Adult stem cells are limited.

Question 12

How is an Induced Pluripotent stem cell made?

Answer 12

If you have a fibroblast/myoblast, you can turn it into a useful stem cell. You just have to introduce four transcription factors (stem cell master regulatory genes).
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