B6 Selective Breeding and Darwin and Wallace

Question 1

What is selective breeding?

Answer 1

Mating the best organisms to get good offspring

Question 2

Why do humans use selective breeding?

Answer 2

To develop new varieties of organisms with beneficial characteristics such as maximum yield, good health, speed, fertility, temperament

Question 3

Why is selective breeding important for food security?

Answer 3

Selective breeding means that a maximum yield can be achieved for meat, milk, grain etc.

Question 4

What qualities can organisms be bred to have?

Answer 4

Speed, fertility, temperament, good mothering skills, good health, disease resistance.

Question 5

What is the basic process of selective breeding?

Answer 5

1 parent organisms with the best qualities are selected.
2 they’re bred with each other
3 the best offspring are selected and bred
4 this process is repeated over several generations to develop the desired traits.

Question 6

What is selective breeding also known as?

Answer 6

Artificial selection

Question 7

What does selective breeding do to the gene pool? And why?

Answer 7

It reduces the gene pool, as the farmer keeps breeding from the best animals or plants, which are all closely related.

Question 8

What is inbreeding?

Answer 8

When farmers breed from animals or plants that are closely related and reduce the gene pool

Question 9

What is the problem with inbreeding?

Answer 9

It can cause health problems, because there’s more chance of an organism developing harmful genetic disorders when the gene pool is limited.

Question 10

Why there be serious problems if a new disease appears in a population with not much variation?

Answer 10

All the stock are closely related to each other, so if one of them is going to be killed by a new disease, the others are also likely to succumb to it.

Question 11

How did selective breeding help Darwin come up with his theory of evolution by natural selection?

Answer 11

He noticed that the selective breeding of plants and animals created different varieties of species and that these new varieties were sometimes very differs from the original version they had descended from.

Question 12

A farmer who grows green beans lives in an area that experiences a lot of drought. Explain how he could use selective breeding to improve the chances of his bean plants surviving droughts. (3 marks)

Answer 12

He should choose the bean plants that are best at surviving the drought (1 mark) and breed them with each other (1mark). He should then continue this process over several generations.

Question 13

What is Charles Darwin famous for?

Answer 13

Coming up with the theory of evolution by natural selection.

Question 14

How did Darwin come up with his theory?

Answer 14

Made observations
Collected evidence
Looked at the work of other scientists to check and improve his explanations
Shared his theory with the scientific community

Question 15

What did Darwin spend 5 years doing?

Answer 15

A voyage around the world studying plants and animals as well as fossils.

Question 16

What did he make observations about?

Answer 16

Similarities and differences between fossils and living organisms, a sell as between organisms on different islands.

Question 17

What did Darwin notice about the variation in members of the same species?

Answer 17

He noticed variations and that those with characteristics most suited to their environment were more likely to survive.

He also noticed that characteristics could be passed on to offspring.

Question 18

What did Darwin do on his return to England to test his theory?

Answer 18

He carried out selective breeding experiments to show how selection of particular characteristics could lead to the development of new varieties of an organism.

Question 19

Who was Alfred Wallace?

Answer 19

A scientist working at the same time as Darwin, who also made observations about organisms and came up with the idea of natural selection, independently of Darwin.

Question 20

What did Wallace propose about populations of the same species who become isolated?

Answer 20

That evolution by natural selection might lead to the development of new species if populations of the same species become isolated from each other and live in different ecosystems.

Question 21

Wallace and Darwin published their papers on evolution together and acknowledged each other’s work. Why is Darwin better known than Wallace?

Answer 21

Darwin’s book ‘The Origin of the Species’ made scientists pay attention to the theory and this is why he is better remembered.

Question 22

What has happened as scientist have discovered more about DNA, to Darwin’s theory?

Answer 22

The evidence has become stronger.

We now know that mutations cause genetic variants which can be inherited and cause variation in a population.

Question 23

What areas of biology and society have been affected by the acceptance of the theory of evolution by natural selection?

Answer 23

Classification
Antibiotic resistance
Conservation

Question 24

How has the acceptance of the theory of evolution by natural selection affected classification?

Answer 24

We now classify organisms based on how closely related they are.

Question 25

What does classify mean?

Answer 25

Arrange into groups based on how closely related organisms are.

Question 26

How has the acceptance of the theory of evolution by natural selection affected antibiotic resistance?

Answer 26

We now understand the importance of finishing the course of drugs to prevent resistant bacteria spreading.

We now know that we need to constantly develop new antibiotics to fight newly evolved resistant bacteria.

Question 27

How has the acceptance of the theory of evolution by natural selection affected conservation?

Answer 27

We one understand the importance of genetic variation and how it helps populations adapt to changing environments.

Question 28

Why is the theory of evolution often misunderstood?

Answer 28

Many people are not aware of the evidence for it.

Some people simply don’t believe in it, often due to religious beliefs.

Question 29

Describe two observations made by Darwin that helped him to develop his theory of evolution. (2 marks )

Answer 29

The similarities and differences between fossils and living organisms (1 mark)

The similarities and differences between organisms living on different islands (1 mark)

The way in which selective breeding can produce new varieties of an organism (1 mark)

(Any two of the above)