Stem cells and genetic manipualtion

Question 1

Zygote

Answer 1

A single cell produced by a fusion of egg and sperm.

Question 2

The inner cells in the embryo…

Answer 2

are the stem cells.

Question 3

Bone marrow

Answer 3

A good source of adult stem cells, however, they can develop to a limited range of types. Used to grow tracheas.

Question 4

Stem cells can be used…

Answer 4

To treat previously incurable conditions. Scientists may be able to grow nerve cells to cure paralysis or grow whole new organs.

Question 5

Problems with stem cells

Answer 5

• many of these cells come from aborted embryos
• violation of human rights, since embryo did not give a permission
• it may cause cancer
• making stem cells is very slow and expensive
• unable to cure genetic diseases

Question 6

Another source of stem cells

Answer 6

• Umbilical cord blood

- amniotic fluid

Question 7

Therapeutic cloning

Answer 7

Involves using the nuclei form the cells of an adult to produce a cloned embryo for themselves. This would provide a source of perfectly matched embryonic stem cells, that would not be rejected by the patient’s body.

Question 8

Tissue culture

Answer 8

Tissue removed from a tip of the plant. Placed on a medium with growth hormones. Hundreds of clones can be made, which are called callus.

Question 9

Embryo transplants

Answer 9

An embryo is created, then split many times into the early stages to form a cloned embryos. Cloned embryos are inserted to mother.

Question 10

Adult cell cloning

Answer 10

A complete set of chromosomes (nucleus) is inserted into an enucleated egg. Electric shock is then stimulated to the egg as a catalyst. This causes the egg cell to divide and starts embryo development.

Question 11

Cuttings

Answer 11

Cuttings are taken with a bud on. Kept them in moist conditions until ready to plant.

Question 12

Adult cell cloning benefits

Answer 12

• help to save animals from extinction
• bring back died species
• genetically engineered cows can produce useful proteins in the milk

Question 13

Adult cell cloning disadvantages

Answer 13

• people fear that it could lead to cloning human babies

- cloning reduces variation in a population, making the population more vulnerable to spread of diseases

Question 14

Genetic engineering

Answer 14

Genes can be transferred to the cells of animals and plant in the early stages of their development so they develop desired characteristics.

Question 15

Enzymes are used to…

Answer 15

isolate and cut out the required gene.

Question 16

The gene is then inserted into…

Answer 16

a vector using more enzymes.

Question 17

Vector

Answer 17

Usually bacterial plasmid or virus. Carries the new gene to another organism.

Question 18

The vector is then used to insert…

Answer 18

The gene into required cells, which may be bacterial, animal, fungal or plant cells.

Question 19

Genetically modified crops

Answer 19

Crops that had their genes modified by genetic engineering techniques.

Question 20

Advantages of GM crops

Answer 20

• increase yields
• modified to make their own pesticides, so they are resistant to attack by insect
• more resistant to herbicides, farmers can spray and kill weeds more effectively

Question 21

Benefits of genetic engineering

Answer 21

• improved growth rates of plants and animals
• increased yield of crops
• crops can be designed to grow in extreme conditions
• crops can be modified to make their own pesticides
• more resistant to herbicides

Question 22

Disadvantages of genetic engineering

Answer 22

• long-term effects are not clear
• effect of GM on human health is not clear
• genes from GM crops can spread to wildlife, affecting the ecosystem and wildlife flowers
• people might want to manipulate genes of children in the future