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Topic 4- Evolution 📄 > Evolution > Flashcards

Evolution Flashcards

1
Q

What is evolution?

A

The gradual change in the characteristics of a species overtime

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2
Q

Who developed the theory of speciation?

A

Alfred Russel Wallace

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3
Q

What is a summary of speciation?

A

Creating new species
(Individuals who didn’t have characteristics to help them survive would die out)

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4
Q

Describe the process of speciation:

A
  1. Variation within a population is a result of genetic mutations
  2. Alleles which provide a survival advantage are selected through natural selection
  3. Populations of species can be isolated so that they can’t breed together
  4. Different alleles may be advantageous in the new environment so they’re selected
  5. Overtime the selection of different alleles increased genetic variation between the 2 populations
  6. When they are no longer able to breed to produce fertile offspring a new species is formed
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5
Q

Who developed the theory of evolution?

A

Charles Darwin

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6
Q

What did Charles Darwin do and who was he?

A

Published the origin of species in 1859 which put forward the theory of evolution
A scientist and naturalist

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7
Q

Describe the theory of evolution:

A
  1. Variation exists within a species as a result of mutation in DNA
  2. Organisms within characteristics most suited to the environment are most likely to survive to reproductive age and breed successfully - survival of the fittest
  3. Beneficial characteristics are then passed into the next generation
  4. Those who aren’t well adapted die out
  5. Over many generations the frequency of alleles for this advantageous characteristic increase within the population
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8
Q

Controversy about theory of evolution:

A

Contradicted the idea that God created all species
Not enough evidence at the time
Mechanism of inheritance and variation weren’t known at the time

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9
Q

When are bacteria resistant?

A

When they aren’t killed by antibiotics

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10
Q

What rate do bacteria produce at ?

A

A fast one

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11
Q

How do bacteria become resistant?

A

They reproduce at a fast rate
Mutations during reproduction result in new gene such as the one for resistance
Exposure to antibiotics=selection pressure so those with no resistant genes die
Other resistant bacteria can reproduce and increase population passing on gene
Presence of new bacteria supports Darwin’s theory for evolution
These bacteria spread diseases rapidly, humans aren’t immune so there is no cure available

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12
Q

Example of bacteria

A

MRSA
Resistant to many types of antibiotics
Common in hospitals

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13
Q

How does fossil evidence show human evolution?

A

How developments in organisms occured

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14
Q

Ardi

A

Oldest known human ancestor
4.4 million years ago
Fossilised skeleton and bone structure is evidence for natural selection

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15
Q

Lucy

A

3.2 million years ago
Bone structure shows she walks upright like humans
Small chimp like skull and brain

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16
Q

Louis and Mary Leakey

A

Discovered fossils in 1950s that supported natural selection theory

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17
Q

Fossil evidence for human evolution:

A
  1. Ardi
  2. Lucy
  3. Louis and Mary Leakey
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18
Q

Stone tools became more..

A

Complex as our brains evolved

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19
Q

Early stone tools

A

Homo habilis (1.5 million years ago)
Basic pebbles tools created by smashing rocks together and used for cracking nuts

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20
Q

Late Stone Age tools

A

Homo neanderthalensis (40000 years ago)
Pointed arrow heads spears and hooks are used for more advanced tasks such as fishing

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21
Q

2 methods for dating:

A
  1. Radiometric carbon dating
  2. Stratifying rock layers
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22
Q

What is carbon dating?

A

Radioactive decay in isotopes of carbon can be estimate how long ago an organism lived

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23
Q

What is stratified rock layers?

A

Looking at layers of sediment in which a rock was found also allows us to date once living fossils and use this to estimate when they were formed

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24
Q

What is a pentadactyl limb?

A

A limb with 5 digits

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25
Where is the pentadactyl limb seen and what does it show?
Seen in a number of organisms showing a common ancestor
26
How many digits does the human hand have and what does this suggest?
5, but bats cats horses and birds have the same pattern between their limbs. It doesn’t mean we have directly evolved from these animals but humans are distantly related to them via a common ancestor
27
What is classification?
Arranging things into groups based on similarities and differences
28
What is artificial classification ?
Observable features
29
What is natural classification?
Evolutionary links
30
Why do we classify organisms?
For our convenience More manageable to study organisms Easier to identify organisms See relationship between organisms
31
What are the levels of classification?
Kingdom Phylum Class Order Family Genus Species
32
What is each unit?
A taxon and specificity increases as you move from kingdom to species
33
What are the five kingdoms?
Animalia Plantae Fungi Prokaryote Protists
34
Animalia
Multicellular Eukaryotic No cell walls Must eat other organisms for energy
35
Plantae
Multicellular Eukaryotic Cellulose cell walls Make own food through photosynthesis
36
Fungi
Eukaryotic Multicellular Chitin cell walls Dead organic matter for energy
37
Prokaryotes
Unicellular No membrane bound organelles Prokaryotic Flexible cell walls
38
Protists
Eukaryotic Some have cell walls Unicellular Eg. Algae
39
What is a species?
A group of similar organisms able to produce fertile offspring
40
What does Chordata mean?
Vertebrae Has a backbone
41
Why was the 3 domain system developed?
Developments in science such as improvements of microscopes and biochemistry know.edge, found that some species were more distantly related than we first thought
42
Who suggested the 3 domain system and what was it based on?
Carl Woese Fundamental difference in their DNA and placed them above kingdoms
43
What are the 3 domains?
1. Archaea 2. Bacteria 3. Eukaryota
44
Eukaryota
Organisms who have a nucleus enclosed in membranes
45
Bacteria
True bacteria
46
Archaea
Primitive bacteria that live in extreme environments
47
Which is more accepted: the 5 kingdom or 3 domain system?
3 domain
48
What is selective breeding?
When humans choose which organisms to breed in order to produce offspring with certain desirable characteristics
49
Describe the process of selective breeding:
1. Parents with desired characteristics are chosen 2. They are bred together 3. From the offspring, those with desired characterises are bred together 4. This process is repeated until all the offspring have the characteristic
50
What can selective breeding lead to?
Inbreeding This reduces the gene pool and if there’s a disease or environmental change species could be extinct as they will all have the same genetic makeup
51
Advantages of selective breeding:
Increase yield of crop and increase quality Can be bred to be resistnat to a disease
52
Disadvantage of selective breeding:
Can lead to health problems in offspring Lack of genetic variation means populations could be wiped out if there was a disease or environmental issue Ethical issues such as the possibility of offspring suffering and reduced quality of life
53
What is tissue culture?
A method of culturing living tissue ie. Making it grow outside the organism with a growth medium
54
What can tissue culture be used for?
Plant/animal/human tissues
55
How is tissue culture performed in plants:
1. Take the plant you want to clone 2. Using tweezers remove a leave of tissue from a fast growing region 3. Using aseptic techiniques place the tissue on a special growth medium 4. Once the tissue has developed enough, it can be transferred to compost for further growth
56
What is an aseptic technique?
Maintains sterile conditions
57
What is a clone?
A genetically identical copy of am organism
58
Benefits of cloning:
Produce lots of offspring with a specific desirable characteristic Increase number of crops resistant to bad weather Can help endangered species
59
Risks of cloning:
Reduce gene pool so they are less likely to survive a disease due to low diversity Clones have low survival rate and tend to have som genetic problems May lead to human cloning
60
What is genetic engineering?
Modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic
61
What are the stages of genetic engineering?
1. Genes from chromosomes are cut out using restriction enzymes 2. The same restriction enzymes are used to cut the vector (any DNA molecule used to carry new DNA into another cell) eg. Virus or bacteria plasmid, in which the genes will be placed 3. Ligase enzyme is used to attach the sticky ends of the gene and vector together (complementary bases pair up) to produce a recombinant gene product 4. The vector is placed in another organism at an early stage in development so the desired gene can move into its cells and cause the organism to grow with the desired characteristic
62
Where is the vector put in plants?
In meristematic, unspecialised cells which can then produce identical copies of the modified plant
63
What is an example of a GM organism and what does it do?
Golden rice Biofortified crop which produces beta carotene which converts to vitamin A Helps parts of the world where there is a deficiency in this May cause health problems
64
What do GM crops do?
Genetically engineered to be resistant in insects and herbicides Increase crop yields
65
What can GM medicine do?
Could cause inherited diseases Can be used for gene therapy
66
Benefits of genetic engineering:
Can be used in medicine to mass produce certain hormones on certain organisms Improve yields/growth rates Introduce different modifications so they can grow in different conditions Can be produced with extra vitamins in places where it’s difficult to obtain them Greater yields can solve world hunger
67
Risks of genetic engineering: eg. GM crops
Don’t completely understand effects on GM crops on humans Could lead to genetic engineering in humans such as designer babies Selection pressure leads to increased resistance to other species creating super weeds and pesticides Could transfer recombinant DNA to other plants which could threaten biodiversity GM crops are infertile and gene could spread leading to infertility in other species
68
What is an agricultural solution?
A solution to cope with demands of a growing population
69
What are 2 methods of agricultural solutions?
1. Fertilisers 2. Biological control
70
What do fertilisers do?
Provide useful nutrients such as nitrates and phosphates to plants making them more resistant to environmental conditions therefore making them grow faster and larger Plants absorb the nutrients form the soil to make healthy new cells
71
Risk of fertiliser
Excess can run into rivers Kills wildlife and affects biodiversity
72
What is biological control?
An alternative method to pesticides where organisms are used to control pests
73
Advantages of biological control
Safer than fertiliser and cost effective
74
Disadvantages of biological control:
Can be invasive and become pests themselves Reduces biodiversity which has a knock on effect on the whole ecosystem
75

Topic 4- Evolution 📄 (2 decks)

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