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biology > Unit 3 Life on Earth > Flashcards

Unit 3 Life on Earth Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

What does biodiversity mean?

A

Biodiversity is the number of different species in a ecosystem

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2
Q

What is a ecosystem?

A

Natural biological unit made up of living and non living parts

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3
Q

What is a habitat?

A

The place where an organism lives

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4
Q

What is a community?

A

All the living organisms that live within a habitat

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5
Q

What is a population?

A

A group of living organisms of the same species eg a herd of sheep

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6
Q

what is a species?

A

a group of organisms that can produce offspring

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7
Q

What is a producer?

A

an organisms that produces its own food

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8
Q

what is a consumer?

A

an organism that gets energy by eating other organisms

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9
Q

what is a herbivore?

A

only eats plants

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10
Q

what is a carnivore?

A

only eats meat/other animals

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11
Q

what is a omnivore?

A

eats plants and animals/meat

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12
Q

what is a niche?

A

the role an organism plays within its ecosystem

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13
Q

what is interspecific competition?

A

competition between different species, for one or a few recourses they require

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14
Q

what is intraspecific competition?

A

competition within the same species, for all of the recourses they require

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15
Q

what competition is more intense?

A

intraspecific

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16
Q

what type of competition is more intense?

A

intraspecific competition

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17
Q

what are abiotic factors?

A

non living variables
- light intensity
- temperature
- soil pH

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18
Q

how do you measure abiotic factors and the precautions needed when using them?

A
  • light meter : don’t shade it
  • thermometer : wipe down the probe afterwards
  • moisture probe : wipe down probe afterwards
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19
Q

what are biotic factors?

A

living factors
- predation
- disease
- food availability

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20
Q

how to sample biotic factors and precautions needed when doing it?

A
  • quadrats : make sure to place quadrats randomly
  • pitfall traps : must be covered so water can’t get in
21
Q

what are indicator species?

A

species that indicate environment quality and pollution levels by their presence or absence
eg lichens, pollution indicators

22
Q

what is the photosynthesis equation?

A

light energy
water+carbon dioxide——>oxygen+sugar
chlorophyll

23
Q

Where is light absorbed in the cell?

A

the chlorophyll found in chloroplasts

24
Q

what is the first stage of photosynthesis?

A

Light reactions
-light from sun captured in chlorophyll and converted to chemical energy to make ATP
- water is split to make hydrogen and oxygen

25
Q

What is stage 2 of photosynthesis?

A

Carbon Fixation
-series of enzyme controlled reactions
-hydrogen and ATP from light reactions combine with carbon dioxide to make sugar

26
Q

what ways can the sugar produced by photosynthesis be used?

A

-energy source (used in respiration)
-energy storage (starch)
-building material (cellulose)

27
Q

what are the limiting factors of photosynthesis?

A

-carbon dioxide concentration
-light intensity
-temperature

28
Q

how can energy be lost when being passed onto the organism that consumes it?

A

-heat
-movement
-undigested materials

29
Q

what organisms use part of the lost energy from an organism?

A

decomposers
consume dead plants and animals

30
Q

how much energy is lost within a food chain and how much is passed on?

A

90% is lost and only 10% is passed on

31
Q

what does an increase in human population require?

A

an increase in food yield
food yield - volume of food frown/harvested

32
Q

what are two common ways to increase crop yield?

A

pesticides - chemicals used to kill pests that damage crops
fertilisers - substance added to soil to increase fertility (increase nitrate content is soil)

33
Q

what are the problems of pesticides?

A

could accumulate in bodies of organisms over time, as passed along the food chain toxicity builds up and can become lethal

34
Q

what are pesticide alternatives?

A

genetically modified crops, biological control

35
Q

what are examples of natural fertiliser?

A

compost, manure, ploughing clover

36
Q

what are alternatives to fertilisers?

A

genetically modified

37
Q

how do plants absorb nitrogen?

A

-nitrates dissolved in soil water are absorbed by roots
-nitrates produce amino acids and are synthesised into plant proteins
-animals consume plants or other organisms to obtain amino acids for protein synthesis

38
Q

what are the problems of fertilisers?

A

fertilisers can leach into fresh water, that cause an algal bloom, this leads to a reduction in oxygen levels

39
Q

what are the stages of algal bloom?

A
  1. fertilisers leach into fresh water
  2. increases algal population, causing algal bloom
  3. reduces light levels, killing aquatic plants
  4. bacteria feed on dead plants, and dead algae so bacteria increases
  5. bacteria use up lots of oxygen, reducing oxygen for other organisms
40
Q

what are mutations?

A

a random change in a organisms genetic information

41
Q

what are factors that increase mutation rates?

A

chemical - mustard gas, cigarette smoke

radiation - UK rays, X rays

42
Q

what is an advantageous mutation?

A

some mutations can give an organism an advantage

43
Q

what is a neutral word mutation?

A

mutations that can neither be an advantage nor disadvantage to the organisms survival

44
Q

what are disadvantageous mutations?

A

is a disadvantage of the survival of the organism

45
Q

what is natural selection?

A

natural selection is the survival of organisms best suited to their environment

also known as survival of the fittest

46
Q

what is speciation?

A

the formation of a new species

47
Q

what are the different barriers?

A
  • geographical barrier
  • ecological barrier
  • reproductive barrier
48
Q

how does speciation occur?

A

after a part of a population becomes isolated by a barrier different mutation occur in each of the sub populations, each sub population evolves until,they become so different they are two different species

biology (3 decks)

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