Life On Earth (Unit 3) Flashcards
1
Q
What name is given to the total variation that exists amongst living things on Earth?
A
Biodiversity
2
Q
What name is given to factors that affect a species and are a result of the activities of living things?
A
Biotic Factors
3
Q
Give some examples of Biotic factors that can affect a species.
A
Availability of food, disease, predators
4
Q
What name is given to factors that affect a species that are non-living?
A
Abiotic Factors
5
Q
Name some Abiotic factors that can affect a species.
A
pH, temperature, rainfall, light intensity
6
Q
Name the biological unit that is made up of living and non-living parts?
A
Ecosystem
7
Q
What name is given to the place where an organism lives?
A
Habitat
8
Q
Name three human influences over the environment that reduces biodiversity.
A
Air pollution, deforestation, desertification
9
Q
When animals graze, what grazing pressure should be applied by the animals to promote biodiversity?
A
Medium pressure
10
Q
Name two gases that contribute to acid rain.
A
Sulphur Dioxide, Nitrogen Oxide
11
Q
When electricity-generating power stations that use water as a coolant put the warm water back into the river, what happens to the amount of dissolved oxygen?
A
Decreases the amount of oxygen
12
Q
Write the overall word equation for photosynthesis.
A
Carbon Dioxide + Water + Chlorophyll + Light = Glucose + Oxygen
13
Q
Name the type of cells in the leaf apart from guard cells that carry out photosynthesis because they contain chloroplasts.
A
Spongy Mesophyll Cells, Palisade Mesophyll Cells
14
Q
Name the pigment found in chloroplasts needed for photosynthesis.
A
Chlorophyll
15
Q
What two substances are classed as the raw materials in photosynthesis?
A
Carbon Dioxide, Water
16
Q
What do the two raw materials in photosynthesis have to be in the presence of in order to combine?
A
Light, Chlorophyll
17
Q
What are the two products of photosynthesis?
A
Glucose, Oxygen
18
Q
What are the two stages of photosynthesis?
A
- Photolysis
- Carbon Fixation
19
Q
During the first stage of photosynthesis, water is split into what two components?
A
Hydrogen and oxygen
20
Q
What happens to the oxygen produced in photosynthesis?
A
Released through the stomata as a by-product
21
Q
What two products formed in the first stage of photosynthesis are taken to the second stage for the process of carbon fixation?
A
Hydrogen and oxygen
22
Q
What is the name of the sugar produced during the carbon fixation step in photosynthesis?
A
Glucose
23
Q
If a plant makes too much sugar, what storage carbohydrate can it be stored as?
A
Starch
24
Q
Some glucose is turned into a structural carbohydrate used to build the cell wall of the plant. Name this structural carbohydrate.
A
Cellulose
25
The rate of photosynthesis can be affected by which environmental factors?
Light Intensity, Temperature and Carbon Dioxide Concentration
26
If one of the environmental factors that controls photosynthetic rate is in short supply, what term can be used to describe it?
Limiting Factors
27
Name three limiting factors of photosynthesis.
Light Intensity, Temperature and Carbon Dioxide Concentration
28
What colour does iodine turn in the presence of starch?
Blue/Black
29
Explain why the rate of photosynthesis decreases at high temperatures.
The enzymes are denatured
30
When carrying out an experiment to show that a plant has photosynthesised, why is alcohol used in one of the stages?
To dissolve the chlorophyll
31
In the experiment to show that a plant has photosynthesised, why is the Bunsen burner turned off after boiling the leaf in water?
Because alcohol is flammable
32
Why is the leaf boiled in water?
To soften the waxy cuticle on the surface of the leaf
33
Identify the main regions in a cross-section through a leaf.
Guard cells, Stomata, Palisade Mesophyll Cells, Spongy Mesophyll Cells, Lower Epidermis, Waxy Cuticle, Upper Epidermis
34
What two factors are used to distinguish between biomes?
Climate and the flora (plants) and fauna (animals) that live there
35
What name is used to describe an organism's role in the community and its whole way of life?
Niche
36
Which type of organism is always found at the start of a food chain?
Producer (Plant)
37
What name is given to an organism that consumes the producer?
Primary Consumer
38
What name is given to an organism that consumes a primary consumer?
Secondary Consumer
39
Name the two ways in which energy is lost at each stage in a food chain.
* Heat
* Movement
40
Name the type of pyramid that shows the number of organisms at each stage in a food chain.
Pyramid of Numbers
41
Name the type of pyramid that shows the total biomass (total mass of living matter) at each stage in a food chain.
Pyramid of Biomass
42
Name the type of pyramid that shows the total energy at each stage in a food chain.
Pyramid of Energy
43
Name the process by which nitrogen is recycled between the air, soil, animals and plants.
Nitrogen Cycle
44
Name the stage of the nitrogen cycle where nitrogen gas is taken directly from the air and changed into nitrates.
Nitrogen fixation
45
Which plants can carry out nitrogen-fixation?
Peas, beans and clover
46
Name the process by which nitrates can be converted back to nitrogen gas in one step.
Denitrification
47
Name the process by which waste material from plants and animals is broken down by bacteria into ammonia.
Decomposition
48
Name the process by which the ammonia in the nitrogen cycle is converted to nitrites and then nitrates.
Nitrification
49
Name the type of competition that occurs between members of different species for a resource that is in short supply.
Interspecific competition
50
Name the type of competition that occurs between members of the same species for a resource that is in short supply.
Intraspecific competition
51
Which squirrel out of brown and grey is more successful at competing for resources?
Grey Squirrel
52
Which fish is more successful at competing for resources, rainbow trout or grey squirrel?
Rainbow Trout
53
What type of competition is represented by seeds in a dish competing for light, water, and soil nutrients?
Intraspecific Competition
54
How do birds like robins and sparrows reduce aggression between members of the same species during intraspecific competition?
Build Territories
55
What do robins do to defend their territories?
Puff out their red chests, sing loud pitched songs and use social signals
56
What name is given to the sampling technique whereby a beaker is placed in the soil and covered over to try and sample the organisms in a soil ecosystem?
Pitfall Trap
57
Why might you not get an accurate picture of what is in a soil ecosystem?
Animals may eat each other if left in the trap too long, Birds might eat the animals, some might fly away if it's not covered over
58
What sampling technique is needed to sample plants growing in a field?
Quadrats
59
What sampling technique is needed to sample the types of organisms in a tree?
Tree-Beating
60
Why might you not get an accurate picture about the types of organism that are in the tree when using tree beating?
Organisms may miss the tray below, some may fly away, or some may not become dislodged in the first place.
61
What sampling technique is used to sample organisms in the water?
Water Net
62
Why might you not get an accurate picture of what is in the water when using a water net?
Organisms might miss the mouth of the net or they may swim through the holes in the net and escape
63
What instrument can be used to measure the light intensity in an ecosystem?
Light meter
64
Why might the reading on a light meter not be accurate?
Somebody might create a shadow by standing in the way of the sensor
65
Which instrument can be used to measure moisture content of the soil?
Moisture meter
66
Why might you not get an accurate reading using a moisture meter?
Probe not wiped in between readings
67
Which instrument can be used to measure the pH of the soil?
pH meter
68
What name is given to a change in the structure or composition of an organism's genetic material?
Mutation
69
What name is given to an individual affected by a mutation?
Mutant
70
What name is given to substances that can increase the rate of mutation?
Mutagenic Agents
71
Name some mutagenic agents.
* X-rays
* Gamma rays
* UV light
* Mustard gas
72
What name is given to inherited characteristics that make an organism well-suited to its environment?
Adaptation
73
What does a desert kangaroo rat do to try and avoid the heat during the day?
Burrows underground where it is cooler
74
What name is given to the process by which the organisms with the phenotypes best suited to the environment are selected?
Natural Selection
75
What name is given to the process by which a new species is made?
Speciation
76
Define a species.
A group of interbreeding organisms that are able to produce fertile offspring
77
What are the steps involved in the formation of a new species (Speciation)?
1. Large interbreeding population
2. Isolation barrier splits the group up
3. Mutations happen in each of the two groups
4. Natural selection occurs in each group
5. Many natural selections later a new species is formed
6. Groups unable to interbreed once the barrier is removed
## Footnote
This process illustrates how genetic divergence can lead to speciation over time.
78
What is the term for the growing of a vast population of one type of crop plant?
Monoculture
## Footnote
Monoculture can lead to increased vulnerability to pests and diseases.
79
Why is there a need for an increase in food yield compared to the food yield in the 1800s?
Increased population
## Footnote
Population growth drives the demand for higher food production.
80
Which nutrient can get depleted from soil if crops are constantly grown on the same bit of soil?
Nitrogen
## Footnote
Nitrogen is essential for plant growth and is often lost through crop harvesting.
81
What chemical can be added to soil to replace the nitrates and phosphates that are depleted?
Fertilisers
## Footnote
Fertilisers help replenish essential nutrients in the soil.
82
If excess fertiliser is added to a river, which water plants will use it as a source of food and grow?
Algae
## Footnote
Algae thrive on nutrients from fertilisers, leading to ecosystem changes.
83
What is the name given to the rapid growth of algae which use fertiliser as a source of food?
Algal bloom
## Footnote
Algal blooms can deplete oxygen levels in water bodies.
84
When algae die in large numbers after growing too fast, who decomposes them?
Bacteria
## Footnote
Bacteria play a crucial role in breaking down organic matter.
85
What happens to the number of bacteria that decompose the algae in a river full of fertiliser?
Number of bacteria increase, oxygen levels decrease
## Footnote
The decomposition process uses up oxygen, harming aquatic life.
86
What do reduced oxygen levels in the river do to fish?
Kills them
## Footnote
Fish require dissolved oxygen for survival.
87
Who would feed on dead fish in a river?
Bacteria
## Footnote
Bacteria continue the decomposition process, recycling nutrients.
88
What chemicals can be added to crops to kill off pests which may ruin a crop?
Pesticides
## Footnote
Pesticides help protect crops but can also affect non-target organisms.
89
What name is given to species that by their presence can tell you about the levels of pollution in an ecosystem?
Indicator Species
## Footnote
Indicator species provide insights into environmental health.
90
What can the presence of different lichens tell you about levels of pollution in the environment?
They can tell you about levels of Sulphur Dioxide Pollution
## Footnote
Lichens are sensitive to air quality, particularly sulfur dioxide.
91
What can the presence of sludgeworm and rat-tailed maggots in a river tell you about the levels of pollution?
They are high and the levels of oxygen are low
## Footnote
These species thrive in polluted, low-oxygen environments.
92
What name is given to the process by which a natural enemy of an animal is used to control numbers of them to stop them being a pest?
Biological Control
## Footnote
Biological control is a sustainable pest management strategy.
93
What organism can be used to control aphids?
Ladybirds
## Footnote
Ladybirds, also known as ladybugs, are natural predators of aphids and are commonly used in biological pest control.
94
Name a virus that was introduced as part of biological control to control the numbers of South American Cottontail Rabbit.
Myxomatosis
## Footnote
Myxomatosis is a viral disease that affects rabbits and was introduced in Australia to reduce the population of invasive rabbits.
