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biology y4 > Biology SB4a > Flashcards

Biology SB4a Flashcards

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AP® Biology flashcards
1
Q

What is a species?

A

A group of organisms that can interbreed to produce fertile offspring

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2
Q

What is a fossil?

A

fossils are remains, impressions or traces of animals, plants and other organism that lived millions of years ago

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3
Q

What is a fossil record?

A

a fossil record is the history of life as documented by fossils, the remains or imprints of organisms from earlier geological periods preserved in sedimentary rock

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4
Q

What does the fossil record show?

A

it can show how the changes in an organism were linked to changes in its habitat it can also show how different species evolved from a common ancestor

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5
Q

What is the definition of evolution?

A

the gradual change in characteristics of a species over time

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5
Q

How is the evolution of a species studied?

A

fossils are discovered put in chronological order and the changes are studied

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5
Q

How do scientist track common ancestors between species?

A

if the two organisms share similar bone structure it shows evidence of a common ancestor

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6
Q

Name three uses of sophisticated stone tools.

A

Any three:

  • Hunting / killing animals
  • Skinning animals
  • Preparing food / cutting food
  • Building shelter
  • Lighting fire
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6
Q

Why are there gaps in the fossil record? (4)

A
  • Soft tissues decay and does not form fossils
  • The hard parts of some organisms were destroyed
  • Some fossils have not been discovered yet
  • Fossils are often broken into pieces
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7
Q

Exam question:
Using the theory of natural selection explain how giraffes evolved to have a longer neck?

A
  • There is GENETIC variation in the population of giraffes
  • Due to mutations
  • Some have shorter necks and some longer by chance
  • The longer necked ones could get food easier so they had a selective advantage
  • They survived, reproduced and passed alleles on to the next generation
  • So the population of long necked giraffes increased
  • While the population with short necks could not get any food and did not survive
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8
Q

What is Selection pressure?

A

Selection pressure is a factor in nature that pressures
some individuals to survive better than others

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9
Q

What is selective advantage?

A

Selective advantage is when some individuals who have are
better adapted have an advantage in surviving

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10
Q

What are some common factors all vertebrates have?

A

Most vertebrates have limbs and their the internal bone structure is very similar e.g. all have radius, ulna, humerus

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11
Q

What is the pentadactyl limb structure?

A

5 digits

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12
Q

What are the 7 levels of classification? (In order)

A

Kingdom
phylum
class
order
family
genus
species

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13
Q

What are the names of the 5 kingdoms?

A

Animals
Plants
Protoctista
fungi
prokaryotae

14
Q

How do fungi feed?

A

They release enzymes out of the body (extracellular) which break down food into smaller molecules which are then absorbed into the fungus (by diffusion or active transport)

15
Q

What are the three Carl Woesen domain systems?

A

Eukarya
Archaea
Bacteria

16
Q

What are the features of Archaea?

A

cells with no nucleus, genes with unused sections of DNA

17
Q

What are the features of Eukarya?

A

cells with a nucleus, unused sections in genes

18
Q

What are the features of Bacteria?

A

cells with no nucleus, no unused sections in genes

19
Q

When does natural selection occur?

A

Natural selection occurs when organisms inherit characteristics that
allow them to survive better in an area.

20
Q

Whatis artificial selection?

A

Artificial selection is when humans choose certain organisms because they have useful characteristics.

21
Q

What are some reasons why we may obtain favorable characteristics? (5)

A
  1. To give higher yields of crops, milk and other products
  2. To make some organisms resistant to diseases
  3. To make some plants resistant to pests
  4. To make organisms survive in harsher climates
  5. To improve the nutritional value/quality of products
22
Q

What is artificial insemination?

A

It is when we get semen from a favorable male and insert it in favorable female and Wait for pregnancy to occur

23
Q

What are the risks of selective breeding?

A
  1. Loss of genetic diversity
  2. Organisms are more vulnerable to change
  3. Animal welfare
24
Q

Why is the loss of genetic diversity a risk of selective breeding?

A
  • Reminder: An allele is an alternative form of the
    same gene found in the same locus (location) on a
    chromosome
  • In selective breeding, only certain alleles are
    selected
  • So, alleles that might be useful in the future are lost
25
Q

Why are organisms being more vulnerable to change a risk of selective breeding?

A
  • Organisms produced are very similar
  • If there is a new disease or the environment
    changes and affects one organism, all others will
    also be affected
26
Q

How is Animal welfare a risk of selective breeding?

A
  • Some selectively bred chickens produce so much
    breast meat that they cannot stand up!
  • Basset hound puppies have such long ears that they
    might trip over them while running!
27
Q

What is genetic engineering?

A

When a gene is removed from the DNA of one organism and is inserted into the DNA of another organism creating a transgenic organism created

28
Q

What characteristics might be useful in crops? (6)

A
  • Pest resistance
  • Frost resistance
  • Herbicide resistance
  • Drought resistance
  • Longer shelf life
  • More nutritious
29
Q

How do we genetically engineer an organism? (9)

A
  1. Get an organism that contains the gene you are interested in
  2. Cut it from the DNA of that organism using restriction
    endonuclease enzymes
  3. This may create sticky ends or blunt ends on the DNA
  4. Get a bacterium and remove its plasmid DNA
  5. Cut the plasmid with restriction endonucleases again to make space for inserting the gene of interest
  6. Insert the gene and use DNA ligase to stick them together
  7. Put recombinant plasmid back into bacterium
  8. Put bacterium to infect the cells of another organism
  9. Grow the cells in the lab until it becomes a new individua
30
Q

Explain how you can genetically modify mice to fluoresce (6m)

A
  1. Find a jelly fish and extract some cells
  2. Cut the gene for fluorescence using restriction enzymes, creating sticky ends
  3. At the same time, get a bacterium and remove its
    plasmid
  4. Cut the plasmid with the same restriction enzymes and
    then insert the gene for fluorescence
  5. Use DNA ligase to stick the DNA pieces together
  6. Put the plasmid back into the bacterium
  7. Take mice embryos and put them with the bacteria so
    that they can incorporate their DNA into the mice DNA
  8. When the embryos are born, they may glow or not so
    you keep repeating until successful
31
Q

Name three advantages of Bt toxin in crops.

A

One advantage is that less crop plants are eaten by pests which results in higher yield
Another advantage is that reduced use of pesticides/ insecticides/ chemicals which results in less money needed for such things and reduced cost
Lastly Bt toxin is naturally occurring so less bioaccumulation

32
Q

Name three disadvantages of Bt toxin in crops.

A

One disadvantage is that pests might develop resistance so they are no longer affected by it when they eat it
Another disadvantage is that it is Reliant on seed companies/ increased cost
Lastly the Bt gene might spread into closely related wild plant species if pollen from a Bt crop is transferred to a related wild plant (gene transfer

33
Q

Advantages of GM organisms. (4)

A

Advantages

  • We can make plants resist the cold
    or pesticides/herbicides
  • We can make rice produce more
    vitamin A for third world countries
    (Golden rice)
  • We can make animals fluoresce
  • We can make bacteria produce
    insulin for diabetics
34
Q

Disadvantages of GM organisms. (4)

A

Disadvantages

  • Genes may affect other organisms
    accidentally via crossbreeding e.g. the
    herbicide genes may go into weeds
    making them superweeds
  • Designer babies and ethical issues i.e.
    Playing God is not acceptable by many
  • Expensive
  • Loss of biodiversity hence loss of food,
    habitats

biology y4 (13 decks)

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