ecology

Question 1

ecosystem definition

Answer 1

a distinct, self-supporting system of organisms with each other in a physics environment

Question 2

producers definition

Answer 2

plants which photosynthesise to produce food

Question 3

consumers definition

Answer 3

animals that eat plants or other animals

Question 4

primary consumer definition

Answer 4

animal that eats producer

Question 5

secondary consumer defintion

Answer 5

animal that eats primary consumer

Question 6

tertiary consumer defintion

Answer 6

animal that eats secondary consumer

Question 7

top carnivore definition

Answer 7

animal that eats tertiary consumer

Question 8

decomposer definition

Answer 8

bacteria and fungi that get their energy from feeding off dead and decaying organisms and undigested waste (such a faeces) by secreting enzymes to break them down. Helps recycle nutrients

Question 9

physical environment definition

Answer 9

sum of the total non-biological components of the ecosystem; water, soil, air, rocks

Question 10

habitat definition

Answer 10

places where specific organisms live

Question 11

population definition

Answer 11

all the organisms of a species found in an ecosystem at any one time

Question 12

biomes definition

Answer 12

large areas dominated by a specific type of vegetation

Question 13

food chain definition

Answer 13

simplest way of showing a feeding relationship within an ecosystem

Question 14

food web definition

Answer 14

gives a clearer idea of all the feeding relationships within an ecosystem

Question 15

what is an ecosystem

Answer 15

a community of living and non living things

Question 16

living

biotic factors:

Answer 16

• predation
• grazing
• disease
• competition
• parasitism
• mutualism

Question 17

non-living

abiotic factors

Answer 17

• climate
• salinity
• temperature
• soil pH
• topography
• light intensity

Question 18

what is a species?

Answer 18

a group of individuals that can reproduce to give off fertile offspring

Question 19

what is a population

Answer 19

all the members of one species living in a habitat

Question 20

what is a habitat

Answer 20

the place where an organism lives

Question 21

what is a community

Answer 21

all the living things, animals and plants, living in a particular habitat

Question 22

what is an ecosystem

Answer 22

a community of living and non living things

Question 23

what is the best way of estimating populations

Answer 23

quadrats

Question 24

why is it important to take a random sample in quadrats

Answer 24

so its an unbiased measurement

Question 25

to work out the total number of species in an area you need to:

Answer 25

- work out the size of the area you are studying - calculate how many quadrats fit into the area: area x size of quadrat - calculate the population: mean number of individuals in one quadrat x numbers of quadrats

Question 26

why is quadrats a suitable method and better than counting every single organism in an area

Answer 26

it takes less time and is cheaper

Question 27

in quadrats how do you ensure the quadrat you choose is random? why is this important?

Answer 27

use a random number generator/dice avoids bias - avoids over/under representation

Question 28

advantages of quadrats

Answer 28

- requires few materials - simple to use - affordable - allows researches to study plant and animal populations spread out over large areas - causes no harm to organisms

Question 29

disadvantages of quadrats

Answer 29

- have to be able to identify all organisms there accurately - can take a long time - quadrats that are too large, to small or spaced inappropriately can result in errors - not useful for very fast moving animals - researches can be inconsistent when counting

Question 30

what must you include when you get asked about sampling in an exam:

Answer 30

1. use several quadrats 2. random 3. use a random number generator 4. count how many are in each square 5. multiply up to calculate total in large field

Question 31

biodiversity definition

Answer 31

measure of the variety of different species in a habitat

Question 32

is biodiversity good

Answer 32

yes because it means a habitat is more stable -> theres a greater variety of species so if theres a change in conditions, theres less chance the whole population will be affected

Question 33

what is a predator

Answer 33

an animal that eats other animals

Question 34

what is prey

Answer 34

an animal which is eaten by another animal

Question 35

what is a herbivore

Answer 35

an animal that eats only plants

Question 36

what is a carnivore

Answer 36

an animal that only eats meats

Question 37

what is an omnivore

Answer 37

an animal that only eats plants and animals

Question 38

what do arrows between the images in food chains represent?

Answer 38

the direction of energy transfer

Question 39

what do food webs show

Answer 39

the energy flow through part of an ecosystem

Question 40

# animal feeding kingdom what do pyramids of numbers represent

Answer 40

the number of organisms in each trophic level (without considering their mass)

Question 41

as you go up trophic levels why are there fewer organisms

Answer 41

energy is lost to the surroundings between each trophic level

Question 42

what do pyramids of biomass represent

Answer 42

the biomass of organisms in each trophic level (without considering their numbers)

Question 43

what is biomass

Answer 43

the dry of one animal or plant species in a food chain or food web

Question 44

why can it be difficult to get valid data for a pyramid of biomass?

Answer 44

- measuring dry biomass means all water has to be removed from the organisms (difficult to do) - an organsim may belong to more than one trophic level, so cannot be easily represented by one bar

Question 45

what ways can energy be lost from each trophic level?

Answer 45

- movement - respiration -> releases heat to surroundings - not digested + absorbed -> faeces - not eaten - death + decompostion -> decomposers

Question 46

what % of energy is passed onto next trophic level

Answer 46

only about 10%

Question 47

how do you calculate the percentage efficiency of energy transfer?

Answer 47

(energy transferred to next level / total energy in) x 100

Question 48

photosynthesis word equation:

Answer 48

carbon dioxide + water -> glucose + oxygen

Question 49

photosynthesis symbol equation:

Answer 49

6CO2 + 6H2O -> C6H12O6 + 6O2