Natural Selection and Genetic modification

Question 1

What is Genetic engineering?

Answer 1

The process of modifying the genome of an organism by introducing a gene from another organism, in order to give a desired characteristic.

Question 2

What can be used to cut up or join DNA pieces together?

Answer 2

Enzymes

Question 3

What are Restriction enzymes used for?

Answer 3

Recognise specific sequences of DNA and cut the DNA at these points - the pieces of DNA are left with sticky ends where they have been cut.

Question 4

What are Ligase enzymes used for?

Answer 4

Used to join two pieces of DNA together at their sticky ends.

Question 5

What are 2 different bits of DNA stuck together known as?

Answer 5

Recombinant DNA

Question 6

What is a Vector?

Answer 6

Something used to transfer DNA into a cell.

Question 7

What are Plasmids?

Answer 7

Small, circular molecules of DNA that can be transferred between bacteria.

Question 8

What do Viruses do?

Answer 8

Insert DNA into organisms they infect.

Question 9

How has genetic engineering played a role in the treatment of diabetes?

Answer 9

Bacterial cells have been genetically engineered to produce human insulin to treat diabetes.

Question 10

Give 2 drawbacks of genetic engineering.

Answer 10

If the crops breed with wild plants, they could spread the new genes into the wild and affect the wild population’s gene pool.

There is a small risk that genetically modified food could negatively affect our health.

Question 11

What do we call crops that have been genetically engineered?

Answer 11

Genetically modified (GM) crops.

Question 12

Describe the steps of genetic engineering (genetic modification).

Answer 12

1) Isolate the desired gene from human DNA using restriction enzymes, forming sticky ends.

2) Use the same restriction enzymes to cut open a bacterial plasmid, forming complementary sticky ends.

3) Insert the desired gene into the plasmid using the enzyme DNA ligase to form a recombinant plasmid.

4) Insert the recombinant plasmid into the host bacteria.

5) Let the bacteria divide and produce the desired protein.

Question 13

Which 2 enzymes are used during the process of genetic engineering?

Answer 13

DNA ligase and Restriction enzymes

Question 14

Give 3 traits that can be altered by genetic engineering in crops.

Answer 14

Increased yield (e.g. larger fruit).
Increased quality (e.g. better taste).
Resistance to disease.
Resistance to insects.
Resistance to herbicides.
Resistance to droughts.

Question 15

How is Genetic engineering useful in medicine?

Answer 15

Researchers have managed to produce human genes that produce useful proteins into sheep’s and cows.

Question 16

What is selective breeding?

Answer 16

When humans artificially select the plants or animals that are going to breed so that the genes for particular characteristics remain in the population.

Question 17

Why are organisms selectively bred?

Answer 17

To develop features that are useful or attractive.

Question 18

Describe the basic process involved in selective breeding.

Answer 18

From your existing stock select the ones which have the characteristics you’re after.
Breed them with each other.
Select the best of the offspring, and breed them together.
Continue this process over several generations, and the desirable trait gets stronger and stronger. Eventually, all the offspring will have the characteristic.

Question 19

Give 3 examples of traits that might be selectively bred for in plants.

Answer 19

Colour of flowers.
Drought resistance.
Improved yield of fruits, grains, and vegetables.

Question 20

Give 2 examples of traits that might be selectively bred for in animals.

Answer 20

Improved yield of meat or milk.
Desirable size, fur colour, level of aggression.

Question 21

What effect does selective breeding usually have on variation within a population?

Answer 21

Selective breeding normally decreases the variation within a population.

Question 22

What is Inbreeding?

Answer 22

Inbreeding is the process of mating together closely related individuals.

Question 23

What are 3 Drawbacks of inbreeding?

Answer 23

Reduces the size of the gene pool.
Rare inherited diseases are more likely to be expressed.
The population as a whole will be more at risk of disease.

Question 24

What can random mutations in a bacterias DNA create?

Answer 24

New alleles, which can change the bacterias characteristics.

Question 25

When bacteria evolve to become able to survive exposure to antibiotics, we say that they have developed:

Answer 25

Antibiotic resistance.

Question 26

How can we reduce the rise and spread of antibiotic resistance?

Answer 26

We should decrease the use of antibiotics. And doctors should not prescribe antibiotics for mild bacterial infections.

Question 27

Why is the spread of antibiotic resistance a problem?

Answer 27

If more bacteria are resistant to antibiotics, we won’t be able to treat those infections this means more people will die of bacterial infections.

Question 28

What do evidence from Fossils suggest?

Answer 28

That humans and chimpanzees evolved from a common ancestor that existed around 6 million years ago.

Question 29

What are Hominids?

Answer 29

What humans beings and their ancestors are known as.

Question 30

What is ‘Ardi’?

Answer 30

A Fossil hominid 4.4 million years old.
Fossil of the species Ardipithecus radius.

Question 31

What are the features of ‘Ardi’?

Answer 31

She had an ape-like big toe to grasp branches.
Had long arms and short legs and her brain size was about the same as a chimpanzee’s.

Question 32

What is ‘Lucy’?

Answer 32

A Fossil hominid 3.2 million years old.
Fossil of the species Australopithecus afarensis.

Question 33

What are the features of ‘Lucy’?

Answer 33

Had arched feet, more adapted to walking than climbing, no ape-like big toe.
Size of her arms and legs was between what you would expect to find in apes and humans.
Her brain was slightly larger than Ardis but similar in size to a chimps brain.

Question 34

What is ‘Turkana boy’?

Answer 34

A 1.6 million year old fossil skeleton of the species Homo Erectus. Discovered by Richard Leakey.

Question 35

What are the features of ‘Turkana boy’?

Answer 35

His short arms and long legs are much more like a human than an ape, and his brain size was much larger than Lucy’s.

Question 36

How can you tell that the different Homo species continued to evolve?

Answer 36

They started using stone tools and these gradually became more complex.

Question 37

What type of tools did Homo Habilis (2.5-1.5 million years ago) species make?

Answer 37

Simple stone tools called pebble tools by hitting rocks together to make sharp flakes. these could be used to scrape mat from bones or crack bones open.

Question 38

What type of tools did Homo Erectus (2-0.3 million years ago) species make?

Answer 38

Sculpted rocks into shapes to produce more complex tools like simple hand-axes. These could be used to hunt, dig, chop and scrape meat from bones.

Question 39

What type of tools did Homo Neanderthalensis (300,000-25,000 years ago) species make?

Answer 39

More complex tools. Evidence of flint tools, pointed tools and wooden spears.

Question 40

What type of tools did Homo sapiens (200,000 years ago-present) make?

Answer 40

Flint tools widely used. Pointed tools including arrowheads, fish hooks and needles appeared around 50,000 years ago.

Question 41

Using Genetic Analysis, what did Woese find?

Answer 41

Some members of the Prokaryote kingdom were not as closely related as first thought.

Question 42

What are the Three domain system?

Answer 42

Archaea, Bacteria and Eukarya.

Question 43

Describe Archaea.

Answer 43

Organisms look similar to bacteria but are actually quite different. Different genetic sequences. First found in extreme places such as hot springs and salt lakes.

Question 44

Describe Bacteria domain.

Answer 44

Contains true bacteria. Almost everywhere.

Question 45

Describe Eukarya.

Answer 45

Includes a broad range of organisms including fungi, plants, animals and protists.