Chapter 6 - Variation, Reproduction And New Technolgy

Question 1

What does asexual reproduction mean

Answer 1

It does not involve the fusion of gametes. All of the genetic information comes from one parent. All of the offspring are genetically identical to the parent so there is little variety

Question 2

What is sexual reproduction

Answer 2

Involves the fusion of gametes. There is a mixing of genetic information so the offspring show variation

Question 3

Why can offspring produced by sexual reproduction not be identical

Answer 3

They have a combination of two sets of genes

Question 4

How can plant be cloned

Answer 4

By taking cuttings and growing them

Question 5

How does tissue culture work

Answer 5

Taking small groups of cells from part of a plant and growing them under special conditions.

Question 6

What is a gene

Answer 6

A section of DNA

Question 7

What can tissue culture be used for

Answer 7

Reproducing large numbers of a rare or top quality plant

Question 8

How does embryo transplants works

Answer 8

An embryo with unspecialised cells is split into smaller groups of cells. Each group of genetically identical cells is transplanted and allowed to develop in a host animal

Question 9

What is the process of adult cell cloning

Answer 9

The nucleus of an adult cell e.g. Skin cell, replaces the nucleus of an egg cell. First the nucleus is removed from an unfertilised egg cell. The nucleus is removed from the skin cell and placed inside the empty egg cell. The new cell is given an electric shock which causes it to start to divide. Once the embryo has developed into a ball of cells it is inserted into the womb of a host mother. Embryo is identical to adult skin cell

Question 10

What are the advantages of adult cell cloning

Answer 10

• Development of cloned animals which have been genetically engineered to produce valuable proteins in their milk. These have uses in medicine
• Cloning can save animals from extinction

Question 11

What are the disadvantages of adult cell cloning

Answer 11

• Concerns about the ethics of cloning
• Cloning limits the variation in a population (limits the gene pool). This can be a problem for natural selection if the environment changes
• Concerns about using the technique to clone humans in the future

Question 12

What does genetic engineering mean

Answer 12

Changing the genetic make up of an organism

Question 13

How is a gene placed in the chromosomes of another organism

Answer 13

The gene is cut out of the chromosome of an organism using an enzyme. The gene is then placed in the chromosome of another organism

Question 14

Why may genes be placed in an organism of the same species

Answer 14

To give it a desired characteristic

Question 15

Why is the gene to produce insulin in humans placed in bacteria

Answer 15

So that the bacteria can produce large quantities of insulin to treat diabetes

Question 16

How are GM crops like

Answer 16

They may be insect or herbicide resistant and usually have increased yields

Question 17

What are the advantages of cloning

Answer 17

• Cloning cattle can produce herds of cattle with useful characteristics
• Adult cell cloning may be used to make copies of the best animals e.g. Race horses

Question 18

What are the advantages of genetic engineering

Answer 18

• If a person has a faulty gene they may have a genetic disorder. If the correct gene can be transferred to the person they could be cured
• Several medical drugs have been produced by genetic engineering, such as insulin and antibiotics
• GM crops include ones which are resistant to herbicides or insects

Question 19

What are the disadvantages of genetic engineering

Answer 19

• GM crops have a bigger yield, but farmers have to buy new GM seed every year because the crops are infertile
• Some people are concerned about accidentally introducing genes into wild flower populations
• Insects which are not pests may be affected by GM crops
• Many people worry about the effect of eating GM crops on human health
• Many people argue about whether or not cloning and genetic engineering are ethical. What will be the long term effects?