Section 4 - Natural Selection And Genetic Modification Flashcards
1
Q
What is binomial system?
A
Way for naming species today
2
Q
What is evolution
A
A gradual change in characteristics in a species overtime
3
Q
What’s used to see human evolution?
A
Fossils
4
Q
Why don’t fossils show smooth changes over time?
A
There is undiscovered fossils
5
Q
How old is Ardi?
A
4.4 million years
6
Q
What features did ardi have?
A
Long arms, leg bones upright to walk, long big toes
7
Q
What did Ardi’s long big toes help her with?
A
Gripping around trees to climb them
8
Q
How old is Lucy?
A
3.2 million years
9
Q
When was lucy discovered?
A
1974
10
Q
When was ardi discovered?
A
1992
11
Q
What features did Lucy have?
A
Could probably walk upright, have toes arranged like humans but more curved
12
Q
Who found homo habilis?
A
Mart and Louis leaky in the 1960s
13
Q
How old are homo habilis fossils?
A
2.4-1.4 million years
14
Q
State features of the homo habilis creatures
A
Short with long arms but walked upright
15
Q
How old is homo erectus?
A
1.6 million years old
16
Q
Where was homo erectus found?
A
Asia but complete skeleton was found in kenya in 1984
17
Q
What did the fact that homo erectus was found is Kenya mean?
A
That humans evolved in Africa
18
Q
How tall was homo erectus?
A
1.79m and strongly built
19
Q
How long ago do we date human like animals using stone tools?
A
3.3 million years
20
Q
How do scientists work out the ages of different layers of rock?
A
Find out the ages of different layers of rock and compare those to the stone tool
21
Q
What are the oldest stone tools like and what are they used for?
A
Very simple, skinning an animal, cutting up meat
22
Q
What is genetic variation?
A
Characteristics of individuals vary due to different genes
23
Q
What is environmental change?
A
Conditions change in an area (eg lack of resource causes competition)
24
Q
What is natural selection?
A
By change, variations of some individuals make them better at coping with change than others, and more likely to survive
25
What is inheritance?
Survivors breed and pass on their variations to their offspring. So next gen. contains more individuals with the better adapted version
26
What is evolution?
If Environmental conditions remain changed, natural selection occurs over and over again and a new species evolves with all the individuals having better a better adapted version
27
Why do elephants and woolly mammoths share a common ancestor?
Because they evolved from the same animal
28
How do bacteria become resistant to antibiotics?
Bacteria in a population vary in amount of resistance / with time antibiotic kill more and more of bacteria and those most resistant take longer to die / resistant bacteria survive and reproduce to create a population of resistant bacteria
29
What happens when people stop taking an antibiotic too early?
It leaves resistant bacteria still alive, making them reproduce and spread, causing infections that can no longer be treated with antibiotics
30
What is the classification system?
Dividing organisms into groups based on what they look like
31
What where the largest kingdoms in the classification system?
Plants and animals
32
What then happened to the groups in the classification system?
They got smaller and smaller and characteristics of organisms in a group got more and more similar
33
What are the last 2 groups in the classification system called?
Genus and species
34
What do the last two groups in the classification system give?
The organisms it’s binomial name
35
Why is using characteristics for classification causing problems?
Because organisms have evolved similar characteristics but are not closely related
36
How did they change the classification system to fix the error?
So that the smaller groups contained organisms that had all evolved from recent common ancestors
37
What are the 5 kingdoms we use today?
Animal, plant, fungus, protist, prokaryotes
38
What are the characteristics of an organism in prokaryotes?
No nucleus / unicellular / flexible cell wall
39
What did the development of genetic analysis show about organisms?
Organisms apart from prokaryotes have unused sections of DNA in their genes
40
What do unused sections of DNA do
Most sections of DNA make protein but these ones do not help with this
41
Why are archaea not in the prokaryotes kingdom?
Because they have unused sections of DNA
42
What are the 3 domains?
Archaea, bacteria, eukarya
43
What are the characteristics of archaea?
Unused sections of DNA , no nucleus
44
State characteristics of bacteria
No nucleus / no unused sections of DNA
45
State characteristics of eukarya
Nucleus / unused sections of DNA.
46
What changes can scientists look at to work out how closely related 2 organisms are
By looking at the slow changes in DNA
47
If 2 organisms have more DNA in common, what does this mean?
They more recently evolved from a common ancestor, so are more closely related
48
Why would our classification system get updated?
As DNA analysis gets faster and more precise
49
What is artificial selection?
When humans choose certain organisms because they have useful characteristics
50
What is selective breeding?
Breeding organisms with better characteristics to get better offspring
51
How do we get new breeds of animal and new varieties of plant species?
Selective breeding
52
Why did farmers selectively breed wheat?
Because the plants produced few grains and the grains fell of the plant when ripe. So selectively bred to get more grain that stayed in plant
53
What characteristics are plants and animals generally bred for?
Disease resistance / yield / coping with environmental conditions / fast growth / flavour
54
What does genetic engineering involve?
Changing the DNA of one organism (it’s genome) by inserting genes from another organism
55
What does genetic engineering produce?
Genetically modified organisms (GMOs)
56
What is the difference between artificial selection and genetic engineering?
Genetic engineering is much faster but more expensive
57
How do they produce golden rice?
Insert two genes into the rice’s genome, one from daffodil one from bacterium. This produces beta-carotene to make vitamin A
58
What are some GMOs resistant to?
Disease causing organisms
59
What are scientists trying to develop with GMOs resistant to disease-causing organisms?
Develop GMO sheep and pigs to treat human disease
60
What can GM bacteria make?
Useful substances like antibiotics and other medicines
61
What causes variation in characteristics?
Different alleles
62
What is the issue with selective breeding?
Only certain alleles are selected so others become rare or disappear and these could be useful for the future (ie in medicine)
63
Why is farming huge numbers of the same breed also a problem?
All organisms are very similar so if a change in conditions affects one organism it affects all organisms (ie rapid spread of disease)
64
State a 3rd problem with selective breeding
Animal welfare (eg. A selectively bred chicken produces so much breast meat it can hardly stand up)
65
Why have crops been GMed to be resistant to insects?
So less insecticide is needed
66
What is herbicide?
Weed killer
67
Why is herbicide a good alternative to GM crops that are resistant
It’s cheaper
68
What is the worry with GM crops?
They may reproduce with wild plant varieties and pass on their resistance genes, these genes may also have unknown consequences in wild plants
69
What do some people think about eating GM organisms?
That they’re bad for health (but there is no evidence to support this)
70
What can GM bacteria produce that is useful?
Insulin
71
Why is GM bacteria a better alternative that insulin from dead pigs and cows?
Because it is cheaper and suitable for vegans or people who don’t eat beef or pork for religious reasons
72
What is a disadvantage to using GM bacteria insulin to dead animal insulin?
The insulin from mammals is different to that in bacteria so not all diabetics can use it
73
What does bacteria have that holds its DNA?
A large loop of DNA and small circles of DNA called plasmids
74
How do you genetically engineer bacteria?
Additional genes are added to a plasmid
75
What is recombinant DNA?
DNA made by joining two sections of DNA together
76
What do scientists use restriction enzymes for?
Cutting a useful gene out of an organisms DNA
77
When cutting DNA with restriction enzymes it leaves strands of DNA with jagged ends, what is this called?
Sticky ends
78
What happens if 2 sticky ends match?
They can be joined together with an enzyme
79
What is the enzyme that joins the sticky ends together called?
Ligament
80
What is a vector?
Something that transfers things from one place to another (one DNA molecule to another DNA cell)
81
State the whole process of how you genetically engineer bacteria
Restriction enzymes make staggered cuts in the dna molecules! producing a few unpaired bases at each ends ‘sticky ends’ / a section of dna containing a gene for making insulin is cut from a human chromosome in this way / restriction enzymes also cut plasmids open by using the same restriction enzymes as used on the human chromosome, the cut plasmids have the same sticky ends / sections of DNA containing insulin gene are mixed with the cut plasmids. The complimentary bases on the sticky ends pair up and the enzyme ligament joins them together / plasmids are the inserted back into the bacteria which are grown in huge tanks. The insulin they make can now be easily extracted
