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Y10 Bio > Variation and evolution > Flashcards

Variation and evolution Flashcards

1
Q

variation factors

A

Environmental
genetic

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2
Q

types of variation

A

continuous (e.g hair colour)
discontinuous (e.g blood type)

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3
Q

why does genetic variation happen

A

meiosis
sexual reproduction
genetic mutation

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4
Q

lamark

A

thought repeated strain would cause changes in an organism and those changes would pass down to offspring (doesn’t work cuz your genes didn’t change)

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5
Q

darwin

A

animals with favorable characteristic are more likely to survive the selection pressure of the environment and hence are more likely to have many offspring to inherit the characteristic (this called natural selection)
over time allele becomes more frequent in the population causing it to have evolved over time

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6
Q

model answer for natural selection

A
  • there is variation for [named characteristic]
  • variation is caused by genetic mutation
  • There is a [x,y,z] selection pressure in the environment
  • better adapted individuals with [named characteristic] are more likely to survive and reproduce passing down the beneficial allel
  • overtime [named characteristic] is more common in population showing how the population has evolved
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7
Q

What is a species

A

If two populations have diverged enough where they can no longer produce fertile offspring they are considered separate species

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8
Q

Isolation mechanics

A
  • continental drift
  • mountain formation
  • splitting of habitat (building roads&deforestation)
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9
Q

Speciation (4-6 marker)

A

1) population gets isolated from initial population and experiences different environmental pressures
2) Isolated population shows variation from mutations
3) Some have a individuals have a survival advantage and are more likely to survive. Different characteristics may be different in the different populations
4) Isolated population changes and is no longer able to interbreed with the original population

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10
Q

Fossil formation (4-6marker)

A

1) Organism dies & sinks to the bottom of the body of water
2) the body is covered in sediment soft parts decay & the sediment turns to rock
3)more sediment settles, more organisms dies & sediment compressed as layers added
4) minerals replace the bone and the skeleton turns to rock
5) rock layers lift up and eroded by winds+rain- fults in the rock expose fossils

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11
Q

The fossil record

A

the further down in layers of sediment you go the further back in time it is- shows how long species existed for

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12
Q

Why is the fossil record incomplete

A
  • fossil need extremely specific conditions (any O2 would lead to decay)
  • soft tissue wouldn’t form fossils (so creatures like jellyfish wouldn’t be preserved)
  • difficult find fossils as often as they are quite deep
  • they are exposed by tectonic plates which can destroy fossils and the tectonic movement can take a long time
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13
Q

causes of extinction

A
  • illegal wildlife trade
  • overfishing/overconsumption
  • Invasive species
  • Habitat loss/destruction
  • pollution
  • climate change
  • population of humans growing
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14
Q

carl linneus

A

swedish biologist who came up with moder classification

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15
Q

why do we classify organisms

A
  • makes them easier to study
  • allows humans to make sense of the living world
  • helps us see how things are related
  • helps recognise biodiversity
  • common language for international scientists to understand
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16
Q

order of classification

A

Kingdom
Phylum
Class
Order
Family
Genus
Species

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17
Q

5 kingdoms

A

Animals- multicellular, heterotrophs (dont make own food)
Plants- multicellular, chlorophyll, cell walls, autotrophs, angiosperm (flowering)
Fungi- uni or multicellular, eukaryotes, reproduce with spores, saprotrophs(involves decomposition)
Prostists- unicellular, eukaryote, some have chlorophyll, can be saprotrophs or autotrophs
Prokaryotes- no nuclei, single cells, plasmids

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18
Q

Binomial system

A

2 latin names (genus and species)written in italics and the genus is capitalised

19
Q

Domains

A

Suggested by Carl Woese and would sit above kingdoms in classification. The 3 domains would be:
- Archea- which can live in extrem conditions (primative forms of bacteria
- Bacteria- simple bacteria
- Eukaryotes- everything else

20
Q

how does antibiotic resistance occur

A

mutation form by errors in copying the DNA but due to rapid multiplication there is a larger shot of it occurring and when people don’t finish their antibiotic prescription resistance occurs

21
Q

How to prevent antibiotic resistance

A
  • Doctors not prescribing antibiotics in non threatening situations
  • completing their courses
  • agricultural use of antibiotics being managed
22
Q

what is a superbug

A

MRSA bacteria which are resistant to most common antibiotics

23
Q

how to selectively breed

A
  • decide on a useful characteristic
  • select parents from a varied population who display the characteristic and breed them
  • meiosis and random combination causes offspring to have random combinations of the parents genome
  • Offsprings with the desired characteristics are bred together
  • continue until entire population has the desired characteristics
24
Q

reasons to selectively breed

A
  • diseases resistance
  • animals with more meat and/or milk
  • Gentler nature
  • larger/ unusual flowers
25
how to selectively breed plants
- pollen transfer from one plant to another - plants prevented from self fertilisation by the stigma having a chemical or being cross pollinated by having a plastic bag placed over it - process repeated until plant breeds true for desired characteristics
26
advantages to selective breeding
- higher economic gain - eliminates disease - new varieties of crops - fitter and stronger animals - does not include genetic modification
27
disadvantages of selective breeding
- animal discomfort - loss of variety/ variation - No control of mutations - inbreeding - susceptible to new diseases
28
Genetic engineering
alters the genome of an organism by inserting different genes Inserted genes can be within species, inter species or even from plants to animals (when from different species the organism is called a transgenic organism)
29
Genetic engineering vs selective breeding
Genetic engineering is : - faster - more predictable - more targeted as it is a single gene But it is: - less natural - long term impact in unknown
30
How bacteria can be used to create insulin and other protien
1) cut out the human chromosome that is responsible for the desired protein using a restriction enzyme 2) using the same enzyme cut open a plasmid to be used as a vector to be inserted into the bacterium 3) place the plasmid into a bacterium which then starts to divide rapidly. As it divides ot will replicate the plasmid forming millions of them all able to create the desired protein
31
Advantages of GM crops
- grow bigger and faster - resistant to diseases - resistant to weedkiller - allows growth in poor growth environments - can allow crops such rice produce chemicals like carotene to ensure more people consume more vitamins
32
Disadvantages of GM crops
- spread of genes to wild plants- possibly creating more superweeds - build up of toxins in the food chain may occur - some foresee lasting environmental damage - human health MAY be affected
33
what is a clone
Is an individual that has been produced by asexual reproduction that is genetically identical to the paret
34
How to clone plants
graftings cuttings tissue cultures
35
cuttings
- take a healthy plant and cut off a small length of stem - dip end in hormone rooting powder - place plant in damp composte - cover plant with a plastic bag to keep it moist (many cutting can be made and they will all grow into new plants)
36
tissue cultures
Must be done in sterile conditions - the group of cells are removed from the plant are called the explant - explant is placed on nutrient rich growth medium - cells divide to make a mass of totipotent cells called the callus - small group of cells removed from the callus and placed on a growth medium to stimulate shoot growth - shoots are placed on growth medium to stimulate root growth - transferred to a greenhouse
37
benefits of tissue cultures
- allows for huge amounts of genetically plants from a small number of cells - desired plant can be chosen and cloned - mature at the same time (easy to grow and harvest) - rapid growth from a seed - meristems ensure plants are free from viruses
38
disadvantages of tissue cultures
- labour intensive - genetic uniformity makes strains susceptible to diseases and changing conditions - prone to failure due to microbial contamination
39
how to clone animals
Reproductive cloning- reproduce a whole organism Non reproductive cloning/ therapeutic - just some cells
40
reproductive cloning
- splitting embryos for embryo transplant - somatic cell nuclear transfer
41
Non reproductive cloning
- New organs or tissues grown as replacement parts - tissue grown with patients own cells so no issues with rejection
42
uses for non reproductive cloning
- skin grafts on burn victims - replacement nerve cells to repair damaged spinal cords - replacement pancreatic cells for diabetes - cloning for scientific research to run tests to find best tests for individual patients
43
pros of artificial animal cloning
- multiple copies of high value animals can be made - rare species populations can be maintained - testing drugs on cell lines reduces need for animal testing and clinical trials - can produce medical treatments to better care
44
Cons of animal cloning
- lack of variation in herds increases susceptibility to diseases and pests - does not increase genetic diversity of endangered species - Adult cell cloning is unsuccessful and animals may have shorter lifespans - ethical concerns - creating embryos just to destroy them

Y10 Bio (6 decks)

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