4.4 Explaining Change- Variation & Evolution

Question 1

What can cause variation in an individual?

Answer 1

a combination of these

Question 2

What is a mutation?

Answer 2

Change in DNA

Question 3

What is a problem of selective breeding?

Answer 3

Inbreeding can occur

Question 4

What is it called if two populations of one species become isolated geographically and evolve in different ways to suit different conditions?

Answer 4

Speciation

Question 5

What is the definition of a species?

Answer 5

Organisms that can breed together to produce fertile offspring

Question 6

Which is the correct order for classifying species?

Answer 6

Kingdom, Phyllum ,Class ,Order, Family, Genus, Species

Question 7

Which of the following is not evidence for evolution?

Answer 7

Natural selection

Question 8

Which two things does the binomial system use to name organisms?

Answer 8

Genus and species

Question 9

Why is genetic engineering better than selective breeding?

Answer 9

Faster

Question 10

Why does sexual reproduction produce a large amount of variation within a species?

Answer 10

Random mixing of genes from both parents

Question 11

What is a mutation?

Answer 11

Changes in DNA

Question 12

When can mutations be beneficial?

Answer 12

If the organism is more likely to survive because of the mutation

Question 13

What is a variant?

Answer 13

Organisms that differ due to genetic mutations

Question 14

Why would a mutation result in a possible change of phenotype?

Answer 14

If it occurs in DNA which is part of a gene

Question 15

Explain why most mutations are not harmful.

Answer 15

They occur in parts of DNA that do not have a function

Question 16

How common are mutations that affect phenotype?

Answer 16

Rare

Question 17

How do mutations lead to a change in the phenotype?

Answer 17

Changes the sequence of amino acids and therefore the protein

Question 18

How long ago did simple life forms first develop?

Answer 18

Over 3 billion years ago

Question 19

What is meant by natural selection?

Answer 19

Variation in a species allowed some individuals to survive better than others

Question 20

What evidence did Darwin use to suggest the theory of natural selection?

Answer 20

Differences in finches on the different Galapagos Islands, due to different food sources on each island

Question 21

How do Darwin’s finches provide evidence for natural selection?

Answer 21

The finches were similar to, but not the same as, those on the mainland. They had changed over time

Question 22

What is a species?

Answer 22

A group of organisms that can breed to produce fertile offspring

Question 23

A mule is a cross between a horse and a donkey. Horses have 64 chromosomes, donkeys 62. Suggest why mules are infertile?

Answer 23

They have 63 chromosomes, which cannot be halved to produce gametes

Question 24

What term describes when populations of organisms become new species?

Answer 24

Speciation

Question 25

Suggest what could happen if a species cannot evolve?

Answer 25

It will go extinct

Question 26

What are fossils?

Answer 26

Remains of dead organisms

Question 27

Amber is fossilised tree resin. It is sometimes found containing preserved organisms. Why haven’t these decayed?

Answer 27

Lack of oxygen

Question 28

Which part of an organism does mineral replacement most commonly happen to?

Answer 28

Bones and teeth

Question 29

What is the evidence that tells us some organisms have changed very little over time?

Answer 29

There are fossils that look very similar to the organism as it is today

Question 30

What is extinction?

Answer 30

When there are no more individuals of a species left alive

Question 31

Why do we have few fossils of early life forms?

Answer 31

They were microbes or soft-bodied

Question 32

How are relative ages of fossil species worked out?

Answer 32

By working out the age of the rock they are found in

Question 33

Describe how antibiotic resistance develops.

Answer 33

A mutation causes the bacteria to be resistant to antibiotics, this bacteria survive and reproduce, passing on resistance

Question 34

Suggest some other characteristics that sheep may be bred for apart from meat.

Answer 34

Wool, milk

Question 35

Describe the technique of selective breeding.

Answer 35

Select organisms with desired characteristics, bred them together and repeat over many generations

Question 36

Suggest two characteristics that a cattle farmer might want to develop.

Answer 36

Meat, milk production

Question 37

Suggest 3 characteristics that crop plants could be bred for.

Answer 37

Increased yield, flavour, disease resistance

Question 38

What could happen to a crop made up of one variety if the environment changed?

Answer 38

Could be wiped out

Question 39

What are the disadvantages of selective breeding?

Answer 39

May reduce genetic fitness of individuals

Question 40

What is inbreeding?

Answer 40

Production of offspring from mating individuals that are closely related genetically

Question 41

How is a useful gene isolated from an organism’s genome?

Answer 41

Cutting it out using enzymes

Question 42

How do scientists transfer an isolated gene into a target cell?

Answer 42

Using a vector

Question 43

Give an example of a vector used in genetic engineering.

Answer 43

Virus or bacterial plasmid

Question 44

What is a vector?

Answer 44

Something used to transfer genes

Question 45

Why do bacteria make effective vectors?

Answer 45

They contain small loops of DNA which can be transferred to other cells

Question 46

Give one useful substance that bacteria have been genetically modified to produce.

Answer 46

Insulin

Question 47

Give two reasons for genetic modification of plant crops.

Answer 47

Increased yield, increased vitamin content

Question 48

Give one benefit and one risk of GM crops.

Answer 48

Benefits – feeding the hungry, treating diseases Risks – cross-pollination, resistant insects

Question 49

What process is the gradual change in the inherited characteristics of a population over time?

Answer 49

Evolution

Question 50

What is the classification system called where names are made up of genus + species?

Answer 50

The binomial system

Question 51

How is selective breeding different from genetic engineering?

Answer 51

Selective breeding - process of breeding plants and animals with certain, desirable genetic features. Genetic engineering - transplanting genes for a desired characteristic into an organism