Applications of Reproduction and Genetics - Finished

Question 1

What is the definition of a clone?

Answer 1

Genetically identical individuals from a single parent.

Question 2

Give an example of natural cloning in plants

Answer 2

Asexual reproduction - Spider plants/ Strawberries (runners)
Daffodils (Bulbs)

Question 3

Give an example of natural cloning in animals

Answer 3

Identical twins. Blastocyst splits forming two identical smaller blastocysts

Question 4

Give examples of how reproduction is used in industry

Answer 4

Embryo Splitting (Cattle) 
Sperm from the prize bull and an egg from the prize cow make a zygote which produces an embryo made up of undifferentiated cells. The embryo is split to make more identical embryos which are then implanted into lower quality cows. The calves will be good quality calves because their genes are from the prize animals

Question 5

What was Dolly the Sheep?

Answer 5

A cloned sheep

Question 6

What was dolly the sheep cloned from?

Answer 6

Megan - A sheep who was genetically modified to produce HGH - Megan was cloned to ame sure that the HGH producing gene was passed onto her offspring

Question 7

How do you clone?

Answer 7

Nuclear transplantation-
Take a body cell from the sheep that you want to clone and an egg cell from another healthy sheep. Take the nucleus out of the egg cell and place the nucleus from the body cell in its place.
Trigger the division of the cells with chemical and electrical stimulation
If it works it should form an embryo which is then implanted into a third sheep.

Question 8

What is one disadvantage of Nuclear Transplantation?

Answer 8

Doesn’t reset the “biological / Chromosomal clock” to 0

Animal has a shorter lifespan because it’s chromosomes are old.

Question 9

What are stem cells?

Answer 9

Undifferentiated/unspecialised cells capable of dividing and specialising into any specialised cells

Question 10

Embryonic stem cells are the best source of stem cells because they can be specialised. Give an advantage and disadvantage.

Answer 10

Advantage - potential to become any human cell type

Disadvantage - End of a potential life

Question 11

In what diseases are stem cells used for treatment?

Answer 11

Alzheimer’s - regrow brain tissue
Parkinson’s
Diabetes - Into pancreas to grow tissue that makes insulin

Question 12

Why do we use adult stem cells?

Answer 12

To overcome the problem of controversy surrounding embryonic stem cells
Means there is not loss of potential life.

Question 13

Give and advantage and disadvantage of the use of adult stem cells

Answer 13

Advantage - No issue of tissue rejection (assuming the stem cells come from the same person)
Disadvantage - Cells are only part specialised

Question 14

What is micropropogation?

Answer 14

cloning of plants

Question 15

What does Totipotent mean?

Answer 15

Potential to become any other plant cell type

Question 16

What plant cells are NOT totipotent?

Answer 16

Xylem and Phloem

Question 17

What is micropropogation used for?

Answer 17

It is used to culture lots of agriculturally/horticulturally important plants - Bananas

Question 18

What is the plant equivalent of a stem cell?

Answer 18

Meristematic tissue
(Meristem - Growing point of a plant)

Question 19

What is a callus?

Answer 19

Undifferentiated cell mass

Question 20

What does micropropogation involve?

Answer 20

1- Cut a growing point of a plant
2- Place meristem onto agar (o2 h2o and nutrients)
3- Callus can be split to get more pieces and grow more calluses
4- Calluses grow in a medium containing plant hormones. Callus tissues differentiate growing into roots and leaves - NOW CALLED AN EXPLANT
5- Then grows until can be planted into the ground

Question 21

Give some advantages of micropropogation

Answer 21

• Genetic stability as produced by mitosis, guaranteed to be the same
• HUGE PRODUCTION RATE - Small space required so you can produce 10,000’s of clones
• Quick process

Question 22

Give some disadvantages of micropropagation?

Answer 22

• Genetically identical - All susceptible to same diseases or change in conditions
• Microbial contamination

Question 23

What does transgenic mean?

Answer 23

Transferal of genes/DNA from one species to another

Question 24

Give examples of GM plants

Answer 24

GM soya - resistant to herbicide
Tomato - “Flavrsavr” contains fish DNA - transcribed into mRNA - sequences block a naturally occurring mRNA that produces ripening enzyme
Banana’s - Vaccines
crops - Natural insecticides - cotton

Question 25

What is a marker gene?

Answer 25

Used to show that a plant has taken up genes - Plants - Herbicide resistance gene - Bacteria - Glow in the dark gene

Question 26

How is a gene transferred into another plant?

Answer 26

- Identify gene to be transferred - cut the gene out using restriction enzymes (from viruses) - use agrobacterium bacteria to insert gene into plasmids (crown gall forming gene - tumour gene) - Expose a plant callus to agrobacterium - insert its plasmids into plant tissue - inserts the DNA

Question 27

What are the advantages of GM crops?

Answer 27

Insert beneficial genes - Improved storage, Health benefits, reduced use of agrochemicals (no bioaccumulation) Increased yields/ economical value

Question 28

What are the disadvantages of GM crops?

Answer 28

Passes genes onto related species (pollen) Long term health risks Negative effect on wildlife? (Bees)

Question 29

What is the Human Genome Project?

Answer 29

Project to identify all of the DNA/alleles/genes in an individual sequence the DNA

Question 30

Who was involved in the HGP?

Answer 30

Governments | Drug Companies - wanted to identify Parkinson's, Alzheimer's and Diabetes genes and make treatments -> ££££

Question 31

What is Somatic Cell Therapy?

Answer 31

Gene therapy , used to treat Cystic Fibrosis

Question 32

What is cystic fibrosis?

Answer 32

caused by recessive gene which causes thick mucus in the lungs which block airways and cause bacterial build up. In cystic fibrosis the transport protein pumps that pump salt into the lngs doesn't work meaning water does not diffuse into the lung and thin the mucus.

Question 33

How is cystic fibrosis treated by somatic cell therapy?

Answer 33

Breathe in the dominant normal allele, wrapped in liposome - can cross cell membrane.

Question 34

What is a problem with somatic cell therapy?

Answer 34

Only treats certain organs

Question 35

What is the advantage of using germ-line therapy/ germinal cell therapy?

Answer 35

treats the embryonic stage - very few cells - easier to treat?

Question 36

What is genetic engineering used for?

Answer 36

bacteria producing HUMAN insulin

Question 37

How does a restriction enzyme work?

Answer 37

Cuts after a specific sequence of bases AATT. Leaves sticky ends. Gene and the sticky ends are inserted into the plasmid using DNA ligase and the Sticky ends join with the plasmid.

Question 38

How is an insulin gene identified/made?

Answer 38

Use mRNA complimentary to the DNA sequence mRNA converted to (single strand of DNA) by reverse transcription (enzyme - reverse transcriptase - viral enzyme) Single strand of DNA converted to 2 strands of DNA (DNA molecule) (enzyme - DNa polymerase) Insulin gene! Insert into plasmid ONLY GOOD IF YOU NEED ONE GENE OR ONE POLYPEPTIDE