Cloning, Genetic Engineering and Evolution

Question 1

How can you clone a plant?

Answer 1

1. CUTTINGS - you can take a cutting from a healthy plant and then plant the cutting in suitable nutrient rish soil which will produce a genetically identical copy of the parent plant.

This is QUICK and CHEAP to do.

2. TISSUE CULTURE - This is where a few PLANT CELLS are put in a GROWTH MEDIUM with HOROMES, and they grow into NEW PLANTs - CLONES of the PARENT.

This is QUICK, requires LITTLE SPACE and can be done ALL YEAR ROUND.

Question 2

How do you clone animals using EMBRYO TRANSPLANTS?

Answer 2

Farmers do this.

1. Get a PRIZE BULL and take some of his sperm cells (but don’t tell him as he may get upset!!).
2. Get a PRIZE COW and then take some of her eggs.
3. You then get the sperm and artifically fertilise an egg (in other words this is done in a laboratory).
4. The fertisled egg then develops into an EMBRYO that develops many times (to form CLONES) before any cells become SPECIALISED.
5. These CLONED EMBRYOS can then be implanted into lots of other cows (yep you heard me into cows who are not the biological mother!!!) where they grow into identical baby cows (called calves) etc.

Question 3

How do you clone an adult animal?

Answer 3

Yep, science fiction is here folks - you can now clone a real live animal!

1. Get an unfertilsed egg cell and remove its genetic material (ie its nucleus).
2. You then have an empty cell and you insert a complete set of chromosomes from an adult body cell (eg skin cell) into the empty egg.
3. The egg cell is then stimulated by an ELECTRIC SHOCK - this makes it start to divide just like a normal embryo.
4. When an embryo is a ball ofc ells, its implaned into an adult female (the SURRIGATE MOTHER) not biological mother - and the embryo grows into an identical copy (clone) of the original adult body cell.
5. This was how Dolly the Sheep was created.

Question 4

What are the negative issues surrounding cloning?

Answer 4

1. Cloning gets you lots of “ideal” offsrping but it also gets you a “REDUCED GENE POOL” - ie there are fewer different ALLELES in a population.
2. If a population are all closely RELATED and a new disease appears then it could wipe out the population as there will be no ALLELE in the population giving RESISTANCE to the disease.
3. Also having people with identical or very closely related genes could result in genetic disorders etc.
4. There is also the ethical issue over whether a human should be cloned. Many countries ban this but in certain middle east countries it is legal. What rights would a clone have if they are produced and grow up in a lab?
5. Any attempt to create a human clone could result after many usuccessful attempts (it took over 60 attempts with Dolly the Sheep) - this could mean humans being born with physical and genetic disorders which are only obviosu after they are born.
6. Cloned animals could be more unhealthy - Dolly had lung condition and early arthritis - although experts not certain this was asa result of the cloning.

Question 5

What are the positive issues surrounding Cloning?

Answer 5

1. Cloning could lead to a btter understanding of the development of the EMBRYO and AGEING and AGE-RELATED DISORDERS.
2. Cloning could be used to preserve ENDANGERED SPECIES.

Question 6

How can change the characteristics of a gene?

Answer 6

By using enzymes you can put a good gene into another organism’s chromosome.

Question 7

How does genetic engineering work?

Answer 7

You can CUT out a useful gene from one organism’s chromosome using enzymes which are also used to CUT the other oganism’s chromosome.

You then insert the useful gene into the chromosome.

Question 8

Give an example of how genetic engineering works in practice

Answer 8

Scientists can create insulin genes or human growth hormone via the use of bacteria which produces them.

Question 9

Can genes be transferred into animals or plants?

Answer 9

Yes.

You can transfer useful genes into animals at the VERY EARLY STAGE of their development (just after FERTILISATION).

Scientists can produce GENETICALLY MODIFIED CROPS that are resistant to viruses and insects

SHEEP have been genetically modifed so that their milk produces drugs taht can treat human diseases.

PHARMING is a made up word which combines farming with pharmaceutical techniques such as the examples above relating to SHEEP and GENTICALLY MODIFIED CROPS.

Scientists are trying to deal with genetic disorders such as cystic fibrosis (caused by faulty genes) by inserting WORKING GENES - this is caused GENE THERAPY.

Question 10

What are the issues of concern regarding genetic engineering?

Answer 10

Genetic engineering is an exciting new area in science which has potential for solving many problems.

However, there are worries about the long term effects of genetic engineering.

Question 11

What are the good things about GM Crops?

Answer 11

1. GM Crops increase the yied of crops meaning more food.
2. GM Crops could be engineered to contain extra nutrients which is especially important in developing nations.
3. GM Crops are being grown elsewhere in the world without any problems.

Question 12

Wht are the concerns about GM Crops?

Answer 12

1. Some say that GM Crops will affect the number of weeds and flowers (thereby affecting the number of insects) that live in and around the crops reducing farmland BIODIVERSITY
2. Some people are concerned about the safety of GM Crops and people are worried they may develop allergies to the food.
3. The BIGGEST CONCERN is that transplanted genes may get out into the natural environment - for example the HERBICIDE RESISTANCE gene may be picked up by the weeds, creating a new SUPERWEED variety.

Question 13

What is the theory of evolution?

Answer 13

More than 3 billion years ago, life on EARTH BEGAN AS SIMPLE ORGANISMS FROM WHICH ALL THE MORE COMPLEX ORGANISMS EVOLVED.

Question 14

What are the three classifications of evolution?

Answer 14

Plants - make their own food and are fixed in the ground.

Animals - move around and can’t make their on food

Microrganisms - different to plants and animals and are single celled.

Question 15

What is meant by EVOLUTIONARY RELATIONSHIPS?

Answer 15

This explains how all living things are related to each other.

Question 16

What is meant by ECOLOGICAL RELATIONSHIP?

Answer 16

This explains how all living things inetract with each other.

Question 17

Explain EVOULUTIONARY RELATIONSHIP.

Answer 17

Species with similar characteristics often have similar genes because they share a RECENT COMMON ANCESTOR so they are CLOSELY RELATED.

Ocassionally gentically different species may look similar because they’re both adapted to living in the same habitat. However they’re not CLOSELY RELATED and have evolved from different ancestors eg sharks and dolphins.

Question 18

What is the EVOLUTIONARY TREE?

Answer 18

This shows common ancestors and relationships between organisms.

Question 19

Applying ECOLOGICAL RELATIONSHIP - what can you say about similarities and differences?

Answer 19

If we see organisms in the same environment with SIMILAR CHARACTERISTICS (but not genetically) such as sharks and dolphins) it suggests they might be in competition.

Differences between organisms in the same environment (dolphins swim in small groups but herring swim in large groups) can show preditor - prey relationships

Question 20

Explain Dawrwin’s theory of NATURAL SELECTION

Answer 20

1. Individuals within a species show variation because of the differences in their genes.
2. Individuals with characteristics that make them better adapted to the environment have a better chance of survival and so are more likely to breed successfully.
3. So the genes that are responsible for the useful characteristics are more likely to be passed on to the next generation.

Example - rabbits have big ears and small ears. Rabbits with big ears are better at hearing out for predictors so the rabbits with small rabbits are more likely to end up as fox food. Big eared rabbits will be higher number and breed more thereby producing rabbits with big ears.

Question 21

How can mutations affect evolution?

Answer 21

1. A mutation is a change in an organism’s DNA.
2. Most of the time mutations have no effect but ocasionally they can be beneficial by prodcuing useful characteristics.
3. This characteristic may give the organism a better chance of surviving and reproducing.
4. If so, the benefical mutation is more likely to be passed on to future generations by natural selection.
5. Over time, the benficial mutation will accumulate in a population eg some species of bacteria have become resistant to antibiotics due to a mutation.

Question 22

Why didn’t people accept Darwin’s theory at the time?

Answer 22

1. It went against religious beliefs (no God as the creator).
2. Darwin couldn’t eplain how these useful characteristics appeared or were passed on as genes and gene mutation were not known at the time.
3. There was little evidence or other studies at the time so scientists didn’t have evidence

Question 23

Explain Lamarck’s theory

Answer 23

Lamarck argued that if a characteristic was used a lot by an organism then it would become MORE DEVELOPED during its lifetime (rabbit using its legs to run a lot would deveop longer legs).

Lamarck belived that these acquired characteristics would be passed on to the next generation.

Question 24

Explain how scientists can develop different hypotheses from similar observations

Answer 24

Scientists can develop different hypothese because they have different beliefs (eg religion) or they are influenced by different people or they just think differently.

When a hypothese is devloped it is important to look at all the evidnec that supports or disproves the theory