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Flashcards in Unit 1 Deck (74):
1

What is biodiversity

Variety of living things in an ecosystem

2

What is ment by a species richness

Measure of
The number of different species
The sizes of different species

3

Factors affecting biodiversity

Pollution
Food chain
Medicines
Exinction

4

Factors classified as biotic are

Of living origin
Predation
Grazing
Competition for food
Space
Shelter
Mates and disease

5

Factors classified as abiotic are

Non living factors
Tend to be physical factors that affect distribution of organisms in habitats
pH
Moisture
Temp
Light
Wind speed

6

How can a yield increase

By intensive farming

7

What is intensive farming accompanied with

Harmful effects such as
Destruction of natural ecosystems and loss of biodiversity
Pollution of the environment
Death of harmful helpful insects due to pesticides
Bioaccumulation along food chains

8

What is a biological control

Enemy specifically targets the pests
No chemicals are used and no chemicals persist in the environment and accumulate in food chains

9

What are GM crops

Genes are altered to allow them to benefit from advantageous properties such as pest resistance

10

What are lichens indicators of

Air pollution

11

What are lichens sensitive to

Sulphur dioxide which is a gas released from car exhausts

12

What is an indicator species

Species that by their presence or absence indicate environmental quality or levels of pollution

13

Why do farmers use pesticides

Kill pests which feed on their crops which reduces the yield

14

Where can pesticides persist

In bodies of plants

15

What is bioaccumulation

Toxic molecules passed along the food chain and become more concentrated at each level

16

What can fertilisers do

Increases crop yield and can have a detrimental effect on environment

17

What can deplete the soil

Constant growing of crops on the same area of land can deplete soil of vits nutrients needed for plant growth

18

How do farmers artificially replace nutrients

Using fertilisers which contain nutrients such as nitrogen and phosphorus

19

What can fertilisers do

Leach into rivers or lochs from fields causing pollution

20

Nitrates from fertilisers cause what

Increased growth of algae called an algal bloom and aquatic blooms

21

Algae

Microscopic plant organisms

22

Eutrophication process

Fertilisers from fields leach into rivers and lochs which causes pollution
Nitrates from fertilisers pollution causes increased growth of algae called an algal bloom
Algae cover surface of river and block light from reaching aquatic plants and they did
Algae also did in huge numbers
Bacteria decompose dead aquatic plants and algae and bacteria numbers explode
Bacteria use up dissolved oxygen in water during respiration
Dissolved oxygen levels decrease and many animals in the river die from lack of oxygen

23

What are GM crops

Useful genes from one organism have been inserted into the cells of a crop plant which gives that plant a desired characteristic

24

Chemical pesticides

Kill pests that would consume the crop

25

Herbicides

Kill weeds that would compete with crop

26

Intensive farming

Enables farmers to produce more food from same average of land involves chemical fertilisers

27

Monoculture

Vast cultivated population of one type of crop whose members are genetically identical

28

Mutation

Only source of new variation among living things
Process by which new alleles of genes have been produced

29

Adaptation

Inherited characteristic that makes and organism well suited to survive in its niche

30

What do we'll adpated organisms cope better with

Changes that occur in the environment
Completion for food
Escaping from predators

31

What is variation

Members of a population who are different

32

Advantageous mutations

Sometimes can be beneficial and improve survival chances

33

Neutral mutation

Don't confer an advantage or disadvantages on organisms they occur

34

Disadvantages mutations

Unfortunately harmful or even lethal as they disrupt proper morning of cells

35

Chemicals

Mustard gas
Benzene on agent orange

36

Radiation

Gamma rays
X- ray
UV light

37

Mutagenic agents

Increase rate of mutation such as radiation and chemicals

38

Mutation

Spontaneous random change to genetic material DNA

39

Says errors can be minimised when using moisture/ pH meter

Wipe probs with tissue before using the probe and between each reading

40

Sources of error with moisture/ pH meter

Moisture/ residue from previous measurement may be left on the probe and affected next reading

41

Sources of error light meter

Someone may stand in way of light and cast a shadow on light meter

Light intensity may change from one moment to next cloud cover makes comparisons invalid

42

Ways errors can be minimised light meter

Ensure all observes stand to one side of light meter
Take all measurements as near same time as possible also take lots of readings

43

Living organism are only able to survive when

In a certain habitat and play it's part in a ecosystem that if a combination of abiotic factors suited to its needs are present there

44

Field ecosystems sources of error minimise error

Carry out large number of quadrant samples whole class pool results
Have a basic rule everyone works by such as if a plant is more than half way inside a plant it should be counted

45

Soil ecosystem minimise error

Disguise opening with a lid eg leaf supported on sticks
Set up several pitfall traps ( replication makes the results more reliable)
Check traps regularly or put preservative liquid such as 50% ethanol in bottom of trap

46

Field ecosystem source of error

Some organism may be located partly inside and outside quadratic
To small a sample therefore not fair representation of organisms present in ecosystem

47

Soil ecosystems sources of error

Birds may eat trapped animals
Some animals may eat others
Number and types of animals may not be representative of ecosystem as a whole

48

Leaf lid

Prevents birds eating insects

49

Soil level

Important to let insects fall

50

50% ethanol

Kills insects to prevent them eating each other

51

Pitfall trap

Works on basis that animal active on soil surface and leaf litter will fall into trap and will be unable to climb out again

52

Estimating total quadrats

Add item divide by quadrats

Total area

Total quadrats = total area divide single quadrats

Total quadrats * item in each quadrats

53

Decomposers

Fungi and bacteria break down dead bodies and

54

Predation

Biodiversity can be maintained by predators- predators. Keep numbers of herbivores down this results in more plants being able to thrive

55

Overgrazing

Overgrazing occurs when herbivore population is high
Plant species disappear from habitat
Biodiversity is reduced

56

Undergrazing

Occurs when herbivore population is reduced
Fewer plants are eaten
Dominant plants out compete less dominant plants don't get a chance to grow
Biodiversity reduced

57

Moderate grazing

Increase biodiversity
Allows less dominant plants to survive as more dominant ones are kept in check by grazers
Reduction in number of dominant species allows less dominant species to gain more light and soil nutrients

58

Predator prey cycles

As time goes on prey population increases as this is when the prey mate
Predator has prey to eat so their numbers will go up
Prey numbers have went down as the predators are eating them not allowing the to reproduce
Since prey numbers are going down the predators are getting excess to less food so their numbers come down
Prey numbers have increased because the predators haven't been eating them as much
Therefore gives prey time to repopulate

59

Community

All of the living organisms in a habitat / ecosystem

60

Habitat

Place where organism lives

61

Population

Total number of organisms of same species living in a habitat

62

Biome

Large geographical region distinguished by climate
Animal and plant communities

63

How does acid rain occur

Gases released by burning of fossil fuels coal oil gas dissolve in rain water and cause it to become acidic

64

Ecological barrier

pH
Salinity
Different habitats

65

Speciation

One population occupies one environment
Population is split into 2 sub populations by a barrier
A mutation occurs in each population individuals with mutation are better able to survive
Mutations and natural selection change each sub population
If barrier removes two sub populations are too different to interbreed and two new species are formed

66

Species

Group of living things that are so similar to one another genetically that are able to interbreed to produce fertile offspring

67

Nitrogen cycle

Plants absorb nitrogen from soil water in form of nitrate and use the nitrogen contained in nitrate to build amino acids and proteins

68

Intraspecific competition

Completion between individuals from the same species all resources required
More intense

69

Interspecific competition

Completion between individuals from different species for 1 or a few resources

70

Pyramids of numbers

Quantative way of representing food chains

71

Pyramids of productivity

Advantages of using pyramids of energy
Always a pyramid shape

72

Ecosystem

Community and habitat and non loving abiotic factors affecting the organisms and with which they interact

73

Ecological niche

Refers to an organisms whole way of life including
Habitat
What it eats or how it uses resources
Effected by disease
How it interacts with other organisms in the community

74

What is natural selection/ survival of the fittest

Basic form of evolution
All organisms produce offspring to carry their species
Organisms carry more offspring than the environment can support
There will be struggle for survival
Organisms will compete for food shelter etc
Variation among species
Offspring whose phenotype are better adapted to their environment have a better chance of surviving to reproductive age
Favourable genes will be passed on to next generation
Organisms least adapted will be weeded out and fail to pass their genes
Process is repeated
generation after generation
Alleles will increases in frequency within population