Topic 7: Ecology Flashcards
1
Q
What are the four levels of organisation within an ecosystem?
A
- Individual Organism
- Population
- Community
- Ecosystem
2
Q
What is the definition of ‘Individual Organism’?
A
Single member of species
3
Q
What is the definition of a population?
A
A number of individuals of the same species living in the same area at the same time
4
Q
What is the definition of a community?
A
Multiple populations (of different species) living and interacting in the same area
5
Q
What is the definition of an ecosystem?
A
The interaction between a community (biotic) and the non-living (abiotic) parts of the environment
6
Q
What is meant by competition?
A
- When all organism need the same resource to survive and reproduce, but there is a limited amount
7
Q
What are the two types of competition?
A
- Intraspecific Competition (Between members of same species)
- Interspecific Competition (Between members of different species)
8
Q
What is meant by adaptation?
A
- Certain features, behaviours, or other characteristics that help it to survive and reproduce in its habitat
9
Q
What are some examples of ecosystems?
A
- Garden Pond
- Woodland
- Coral Reef
- Desert
10
Q
What are some examples of interactions within an ecosystem?
A
- Predators (carnivores) eating prey
- Herbivores eating plants
- Plant species being pollinated by bees
11
Q
What resources do plants compete for?
A
- Light
- Space
- Water (from soil)
- Mineral Ions (from soil)
12
Q
Why do plants compete for light?
A
- Photosynthesis
- Production of glucose
- Energy for growth
13
Q
Why do plants compete for space?
A
- Need space both above and below soil
- Leaves for max. sunlight
- Roots for max. resources
14
Q
Why do plants compete for water?
A
- Photosynthesis
- Plant Growth
15
Q
Why do plants compete for mineral ions?
A
- Nitrate Ions (Make Proteins)
- Magnesium Ions (Make Chlorophyll)
16
Q
What resources do animal compete for?
A
- Food
- Mates
- Territory
17
Q
Why do animals compete for food?
A
- Provide Energy
- Growth and Reproduction
18
Q
Why do animals compete for mates?
A
- Production of offspring
- Pass on genes
19
Q
Why do animals compete for territory?
A
- Area of habitat
- Provides individual with resources
20
Q
What is interdependence?
A
- Within a community, each species depend on other species for food, shelter, pollination etc.
- One species is removed, it can affect whole
21
Q
What is a stable community?
A
- All the species and environmental factors are in balance so that population sizes remain fairly constant
22
Q
What are examples of abiotic factors which affect a community?
A
- Light Intensity
- Temperature
- Moisture Levels
- Soil pH and Mineral Content
- Wind Intensity and Direction
- Carbon Dioxide Levels for Plants
- Oxygen Levels for Aquatic Animals
23
Q
What are examples of biotic factors which affect a community?
A
- Availability of Food
- New Predators
- New Pathogens
24
Q
What are the three types of adaptation?
A
- Structural
- Behavioural
- Functional
25
What is a structural adaptation?
Physical part or feature of an organism
26
What is a behavioural adaptation?
Way an organism behaves
27
What is a functional adaptation?
Biological Processes within the organism
28
What are examples of adaptations to cold regions?
- Small surface area : volume ratio to minimise heat loss
- Thick layer of fat or fur insulates against cold
29
What are examples of adaptations to desert regions?
- Concentrated urine to retain water
- Only active in early mornings, late evenings or at night when it is cooler
- Increased surface area : volume ratio to aid heat loss
30
What are environments which could be described as extreme?
- High / Low Temp.
- High / Low Pressure
- High Salt Concentration
31
What are organism which can live in extreme environments known as?
Extremophiles
32
What is an example of a habit in which an extremophile could be found in?
- Deep-sea volcanic vents
- Extremely hot
- High pressure
- No sunlight
33
What are the producers of biomass for life on Earth?
- Photosynthetic organisms which produce own food using energy from Sun (autotroph)
34
What does a food chain begin with?
Producer
35
What is a simple way to show feeding interactions between the organisms in a community?
Food Chain
36
What are primary consumers?
- Herbivores/Omnivores
- Eat producers
37
What are secondary consumers?
- Carnivores/Omnivores
- Eat primary consumers
38
What does a food chain show?
Transfer of energy from one organism to the next
39
In which direction are the arrows in a food chain?
Represent flow of energy; producer to consumer
40
Is a consumer a autotroph or a heterotroph?
- Heterotroph
- Cannot produce own food
- Take nutrition from other sources
41
What is ecology?
Branch of biology that studies the distribution and abundance of species, the interactions between species, and the interactions between species and their abiotic environment
42
What are quadrats?
Square frames made of wood or wire used to measure the abundance of plants or slow-moving animals.
43
What sizes can quadrats be?
Various sizes, typically 0.25m² or 1m².
44
What three measurements can be recorded using quadrats?
1) Number of an individual species, 2) Species richness, 3) Percentage cover.
45
When would you use percentage cover as a measurement?
When it is difficult to count individual plants (e.g., grass or moss).
46
How do you decide whether to count a square when estimating percentage cover?
Count the square if more than half of it is covered by the species.
47
What is a transect used for?
To measure how the abundance of a species changes along a changing habitat.
48
How is a transect set up?
A line (transect) is established through the changing habitat using a tape measure with quadrats placed at regular intervals.
49
What are examples of changing habitats where transects might be used?
Changing altitude on a hillside, transition from open field to dense woodland, or along a shoreline.
50
What abiotic factors might be investigated using transects?
Light intensity, moisture levels, soil depth, altitude, etc.
51
What is typically recorded at each interval along a transect?
Number of an individual species, species richness, or percentage cover.
52
What statistical measurements should you understand when studying organism abundance?
Mean
53
What graphing skills are needed when studying organism abundance?
Plotting and drawing appropriate graphs with suitable scales for axes.
54
What is the sequence of feeding relationships in an ecosystem?
Producers → primary consumers → secondary consumers → tertiary consumers.
55
What are predators and prey?
Predators are consumers that kill and eat other animals; prey are the animals that are eaten.
56
What pattern occurs in predator-prey cycles in a stable community?
The numbers of predators and prey rise and fall in cycles.
57
What happens to predator numbers when prey numbers increase?
Predator numbers increase as more prey becomes available.
58
What happens to prey numbers when predator numbers increase?
Prey numbers decrease as there are more predators.
59
What is the sequence of a predator-prey cycle?
1) More prey → more predators, 2) More predators → fewer prey, 3) Fewer prey → fewer predators, 4) Fewer predators → more prey, and the cycle repeats.
60
What are trophic levels?
- Position of an organism in a food chain, web or pyramid
61
How does energy flow begin in an ecosystem?
Energy flows from the Sun to the first trophic level (producers) in the form of light.
62
What do producers convert light energy into?
Producers convert light energy into chemical energy.
63
What happens during photosynthesis?
During photosynthesis, producers convert carbon dioxide and water into glucose and oxygen.
64
How is energy transferred from producers to primary consumers?
Chemical energy is transferred to primary consumers as they consume (eat) producers.
65
How does energy continue to flow through a food chain?
Chemical energy is transferred from one consumer to the next as they eat one another.
66
What are apex predators?
Carnivores at the very top of the food chain with no predators.
67
What happens to the energy stored in apex predators when they die?
The chemical energy stored within apex predators can be passed on to decomposers when apex predators die and are decomposed.
68
Can organisms belong to more than one trophic level?
Yes, some organisms can belong to more than one trophic level in a food web.
69
What are the two main groups of decomposers?
Bacteria and fungi.
70
What important function do decomposers perform in ecosystems?
Decomposers break down dead plant and animal material.
71
How do decomposers break down dead matter?
By secreting digestive enzymes onto the surface of the dead organism, breaking down the dead matter into small soluble food molecules, which are then absorbed by the decomposers.
72
How does decomposition benefit the ecosystem?
Decomposition releases organic nutrients back into the environment (e.g., the soil) which are essential for the growth of plants (producers).
73
What is biomass?
Mass of living tissues (or recently dead tissues that have not decomposed) that a plant or animal is made up of
74
What does a pyramid of biomass shows?
The relative biomass (mass of living or recently dead material) at each trophic level in a food chain
75
How much biomass is passed on to the next trophic level?
Approximately 10%
76
What is the normal amount of trophic levels on a food chain?
Rarely made up of more than 6 as total biomass available is too small to support another level
77
Why is biomass lost?
- Organism rarely eat every part of organism, biological matter may be inedible
- Not all ingested material is digested and absorbed
- Some absorbed material lost as waste
78
What is the biomass efficiency transfer equation?
Biomass in Higher Trophic Level / Biomass in Lower Trophic Level x 100
79
True or False: Animals can be in two trophic levels at once
True, trophic level can change depending which chain you follow
