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Unit 4 - Natural Selection And Genetic Modification Flashcards

1
Q

What is evolution

A

To gradual change in characteristics of a species over time

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2
Q

Why do you fossils is not show smooth changes over time

A

Because not all have been discovered

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3
Q

What is the name of the most complete set of fossils

A

Ardi

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4
Q

What species is Ardi from

A

Ardipithecus ramidus

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5
Q

Give three characteristics of Ardi

A

About 1.2 m tall, very long arms, may have been able to walk right

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6
Q

What species is Lucy

A

Australopithecus afarensis

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7
Q

What is the species name for modern humans

A

Homo sapiens

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8
Q

What species did Homo sapiens evolve from

A

Homo neanderthalensis

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9
Q

How can scientists work out the ages of stone tools

A

Using the different layers of rock. The stone tool is about the same age as the layer of rock

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10
Q

What could the oldest stone tools be used for

A

Skinning an animal or cutting up meat

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11
Q

Which two scientists came up with the idea of evolution

A

Charles Darwin and Alfred Russell Wallace

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12
Q

What does genetic variation mean

A

When the characteristics of individuals vary

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13
Q

What is environmental change

A

When conditions in an area change. For example, the lack of resaws such as food

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14
Q

What is natural selection

A

Sometimes the variations of some individuals make them better at coping with changes and are more likely to survive

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15
Q

How does evolution happen

A

If the environmental conditions remain changed, natural selection occurs over and over again, and a new species evolve with all the individuals having the better adapted variations

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16
Q

Given examples of how a species could have evolved

A

The environment could be getting cold so for some animals who may have been hairier would have survived against the cold. These animals would have bred and overtime the animals became hairier and hairier forming a new species

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17
Q

What was warfarin used for

A

Poison rats

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18
Q

How did the rats become resistant to warfarin

A

Due to genetic variation they had always been rats that were resistant. As the poison killed the non-resistant, the only ones left to breed were resistant

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19
Q

Give two examples where species had become resistant to poisons

A

Rats to warfarin and bacteria to antibiotics

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20
Q

How can stopping an antibiotic early develop a species resistant to the antibiotic

A

Some bacteria would be more resistant to the antibiotic. When the antibiotic course is started, the less resistant bacteria are killed. If the course is finished early, the more resistant bacteria would still be alive and would also breed. This creates a new population of bacteria that are resistant to the antibiotic

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21
Q

Why did scientists used to think that the Earth species could not evolve

A

They thought that God had created all of species and their characteristics could not change

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22
Q

How did Darwin begin to think about evolution

A

He noticed differences between mockingbirds on different islands and wondered whether a species could change form if it moved into a different area

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23
Q

What explanation did Darwin have for evolution

A

Organisms normally produce more of offspring than what could survive. Only the individuals best suited to the surroundings would survive and reproduce to pass on their characteristics

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24
Q

What organisms had Wallace studied

A

The tiger beatles, he noticed that in Indonesia they were different colours depending on where they live to camouflage them. Natural selection allowed him to explain it

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25
What is a pentadactyl limb
A limb with five fingers
26
What does the pentadactyl limb suggest
There was evolution from a common ancestor and not that all bones were designed for specific purposes independently of one another
27
What is classification
Dividing organisms into groups based on what they look like
28
What the 5 kingdoms
Animals, plants, fungi, protists and prokaryotes
29
What does the last group contain of classification
One type of organism
30
How did Lennaeus give each organism binomial name
Using the two last groups, genus and species
31
Why might there be problems using characteristics for classification
Some organisms have evolved similar characteristics but are not closely related
32
How did modern scientist alter the classification system
They made it so that the smaller groups contained organisms that have evolved from recent common ancestors
33
What is Archaea?
A group found in the prokaryote kingdom where the organisms are single celled that have no nuclei
34
What is the three domain system of classification
This was created by call roads and all organisms should be divided into archaea bacteria, eukarya.
35
How can you tell how closely related organisms are
The more DNA two organisms have in common, the more recently they evolved from a common ancestor so the more closely related they are
36
What is natural selection
When by chance, some individuals inherit characteristics that allows them to survive better than others in a certain area
37
What is artificial selection
When humans choose organisms because they have useful characteristics, such as sheep with thick wool
38
What is selective breeding
When people bred organisms that have useful characteristics to humans. This results in offsprings that inherit the characteristics so by repeating this process, you would eventually get organisms with the most useful characteristics
39
What is selective breeding used today for
To produce new breeds of animals and new varieties of plants species
40
Give two examples of how people have used selective breeding
When farmers selectively bred wild wheat plants. When people selectively bred hairier sheep
41
Give five reasons why plants and animals are often selectively bred
Disease resistance, yield (quantity), coping with certain environmental conditions, fast growth, flavour
42
What is genetic engineering
Changing the DNA of an organism, it’s genome, often by inserting genes from another which creates genetically modified organisms
43
Give a positive and negative of genetic engineering compared to selective breeding
Positive: much faster Negative: much more expensive
44
Give an example of a GMO and why it is useful to humans
Golden rice which has two jeans inserted into it Gino, one from a daffodil and one from a bacteria. It makes the rice produce beta-carotene in its grains. This makes vitamin A to stop the cause of blindness
45
Why are GMO is used today
Resistant to disease causing organisms In goats and sheep, to produce proteins in their milk that can treat human diseases GM pigs with human like organs to use in organ transplants Salmon that grow much faster
46
What is tissue culture
The growing of cells all tissues in a liquid containing nutrients or on a solid medium
47
What is a callus
A clump of undifferentiated cells
48
What is tissue culture used for
To produce new plants of very rare species which are at risk of extinction To produce new individuals of plant species that may be difficult to grow from seed To produce clones of GM plants
49
Why are some undifferentiated cells in a callus treated
To make them differentiate, to become specialised
50
Give the steps of tissue culture
A piece of plant in placed in bleach solution to sterilise it Only a few cells are cut off and placed on sterile nutrient medium to grow into a callus The callus is treated with hormones so that the plantlets develop with shoots and roots The plantlets are separated and grown on nutrient medium in sterile conditions When the plants are large enough they are planted into soil or compost
51
Why is tissue culture used in medicine
Cutting a thin-layer of cells makes it easier to study how the cells communicate with each other To study for viruses which cannot replicate outside of cells To study how cancer spreads How infected cells respond to new medicines without receiving harm to animals or humans
52
What are alleles
The different forms of genes
53
What happens to alleles during selective breeding
Certain alleles are selected however others become rare or disappear. This means that alleles that might be useful in the future are no longer available
54
Give some negatives of selective breeding
If a change in a condition occurs, all organisms are affected. For example a new disease Animal welfare. For example some selectively bred chickens produce so much breast meat they can hardly stand up
55
Why have GM crops been produced
To be resistant to some insects so less insecticide is needed To be resistant to certain herbicides so it kills weeds but not the crop
56
What might happen if GM plants reproduce with wild plant varieties
The genes may have unknown consequences in wild plants
57
State a benefit of golden rice
It produces vitamin a which helps with the cause of blindness
58
Why might GM bacteria be produced
To produce useful substances such as insulin
59
Give a positive and negative about insulin produced by GM bacteria
It is cheaper and suitable for vegans or religious people | It is slightly different to insulin from mammals so not all diabetics can use it
60
State the process of genetic engineering of bacteria
Restriction enzymes makes staggered cuts in DNA molecules, containing the gene, producing sections with a few unpaired bases at each end called sticky ends Restriction enzymes also cut plasmids in the same way so they also have sticky ends The sections of DNA or mixed with the cut plasmids. The complimentary bases on the sticky ends are paired up and an enzyme called ligase is you used to join the ends together The plasmids are inserted back into bacteria which of then grown in huge tanks
61
What are plasmids
Small circles of DNA found in a bacterium
62
What is recombinant DNA
When DNA is combined in a new way
63
What is a vector
A DNA molecule used to carry new DNA into another cell
64
What is the yield
The amount of the crop we can use
65
What is Bt toxin
A natural insecticide protein
66
Give an advantage of GM Bt toxin
It only affects insects that chew on the plant tissues so insect predators are not harmed for example ladybirds
67
Why might other pests not be affected by Bt toxin
Aphids suck sap from the plant but do not chew the plant tissue
68
Why is having different varieties of Bt toxin bacteria a positive
When the pests develop resistance to the toxin the GM crop plants can be developed in the new varieties
69
What is biological control
Using organisms to control pests
70
Give an example of biological control
Using Weaver and nests as they remove some insect pests
71
What are fertilisers
Chemical compounds use to increase food production
72
How can pollution be caused by fertilisers
If not all of the fertiliser is absorbed by a crop some make it into a nearby stream, lake or river
73
What impact can water pollution have on other organisms
It can lead to the death of organisms in the water and also cause health problems for humans and animals if they drink the water

Biology (9 decks)

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