Bio Chp 15

Using technology to control biological processes as means of meeting societal needs


Includes a wide range of procedures for modifying living organisms according to human purpose

(examples: domestication of animals, cultivation of plants)

• Transgenic biotechnology
• reproductive cloning
• forensic biotechnology
• stem cells

Organism whose genome has stably incorporated one or more genes from another organism

• EXAMPLE: "golden rice"
• different from regular rice not only in color but in dietary means. contains beta-keratin whichs helps with Vitamin A

• HGH normally secreted by pituary gland
• abnormal growth as a result of faulty gland

• BEFORE: extracted HGH from dead people
• NOW: made in transgenic bacteria with human HGH gene incorporated

• Recognize a particular DNA sequence and cut whereever they encounter it.
• -Each enzyme has its own recognition sequence
• -derived from bacteria

• Resulting from DNA fragments that have protruding ends
• -allows complentary strand to "stick" to the DNA

Production of medicines and vaccines

Examples: human insulin & cancer-fighting compounds

Variety of transgenic organisms (not just bacteria. example: goats milk)

• planted in abunce in the US
• -mostly soybean, cotton and corn

• Main Reasons:
• insect resistance
• herbicide resistance
• MORE REASONS:
• Disease resistant
• Cold tolerant
• Drought/sallinity tolerant
• more nutrious
• pharmaceutical-producing
• phtoremediators

EXAMPLE: transgenic corn contains gene from the bacteria Bacillus Thuringiensis which incodes for a toxin that kills insect pests

• Unintended harm to other organisms
• (ex: monach butterflies)

Reducing pesticide effectiveness

• Gene transfer to non-target species
• (ex: weeds)

Risk of creating new allergen

Unkown effects of human health

Patenting issues

Encourages use of pollutants on field crops

• a genetically identical copy of a biological entity
• -Genes, cells, organisms

intended to produce adult mammals of a defined genotype

• EXAMPLE:
• Dolly the sheep; was an exact genetic replica of another sheep

Cloning mammals by fusing a somatic ('non-sex') cell with an "enucleated" egg cell

Nucleus removed

Take nucleus from a body cell and put it into an egg cell whose genetic material has been removed.

• No known human cloning has taken place
• scientiest have done SCNT to produce a human embryo for stem cell research purposes

• What would a human clone look like?
• A genetic replica: same DNA sequence
• Similar to identical twins
• -only with an age difference

• DNA can be used to identify ...
• -identities of criminals, biological fathers, disaster victims

• Before:
• Thumbprints were main way to identify people

• Now:
• only need a tiny speck of body tissue

• a technique for quickly producing many copies of a DNA segment.
• -"DNA Amplification"

• Requires:
• DNA sample, collection of nucleotides, DNA polymerase, primers

Human Genomes have lots of short DNA sequences that are repeated from 3-50 times

STR: short tandem repeat

• EXAMPLE:
• TCAT

• Different people have different # of repeats
• -Person 1: TCAT TCAT TCAT
• -Person 2: TCAT TCAT TCAT TCAT TCAT

**Very unlikely that 2 unrelated people will have same number of repeats even at one location in the genome**

look at STR's at 13 different locations

• Most body cells have undergone commitment
• -cell's role is completely determined

• Cells in early embryo that have yet to have undfergone commitment
• -can give rise to various cell types
• -relatively small number of cells with similar capability in adult body
• -both are considered stem cells

• Produce more cells of their own type
• and produce at least one time of specialized

• embryonic blastocyst
• -a source of stem cells

embryonic stem cells (ESCs) that can give rise to all of the different cell types in the human body

• found in small numbers in various body tissues
• different from ESCs because not as flexible, normally found in body tissue

• Researchers originally had to destroy the embryos the cells are part of...
• -can be viewed as destruction of human life
• Bush limited the funding of research for embryo research
• --funding increased by private sources.

• can make ESCs without the need to use embryos
• derived from ordinary cells of children or adults
• --insert 4 genes into cells to induce stem cells

cells derived from ESCs and then introduced into a human body may set off immune system and attack


-can be avoided if individuals produce their own stem cells

CLONING TO PRODUCE HUMAN EMBRYOIC STEM CELLS THAT CAN BE USED TO TREAT DISEASE AND INJURY

a standard cell from an adult body used as the donor-DNA cell in the SCNT cloning process


result allows embryo to divide to the blastocyst stage.

then can be used to help repair body of the individual who provide the donor-DNA cell