Ecology MOCKS

Question 1

What is an ecosystem

Answer 1

A unit containing all of the organisms and their environment, interacting together, in a given area e.g. decomposing log or a lake.

Question 2

What is a community

Answer 2

All the populations of the different species living in a habitat e.g. rock pool consisting of seaweeds, sea anemones, shrimps, fish, crabs & more.

Question 3

What is a population

Answer 3

A group of organisms of the same species living in a habitat e.g. skin mites in a mattress.

Question 4

What is a habitat

Answer 4

The place where an organism lives.

Question 5

Practical investigating the population size of an organism using quadrats

Answer 5

Place the tape measures along the edges of the lawn, forming an X and Y axis.
Use the random number generator to generate a set of coordinates (numbers need to be between 1-100
Place the bottom left corner in the location stated by the co ordinates
Using the species key, identify any thistle, daisy or dandelion plants found within the quadrat. (NB: the root of the plant needs to be present in the quadrat for it to be counted)
Count the number of thistles, daisies and dandelion plants in the quadrat.
Note this down in the results table
Repeat from step 2 for another 9 quadrats.

Question 6

What is biodiversity NOT MOCKS

Answer 6

the variation shown by organisms in an ecosystem

Question 7

Biotic factors affecting population size and distribution of organisms
NOT MOCKS

Answer 7

feeding of herbivores on plants (increased seed dispersal leads to increased spread of plants/ less leaves so can’t photosynthesise

predation (increased number of predators resulting in a decreased number of prey)

competition (more organisms increases competition

parasitism (reduce number of organisms)

mutualism (both organisms work to benefit each other)

Question 8

Abiotic factors affecting population size and distribution of organisms
NOT MOCKS

Answer 8

temperature (organisms have optimal temperature so if temperature changes from optimal the organism can’t effectively function)

light intensity (reduced/increased photosynthesis)

oxygen concentration (less respiration reduces energy released reducing reactions leading to more deaths)

carbon dioxide concentration (reduced photosynthesis reduces glucose levels and respiration)

water supply (reduces photosynthesis leading to death)

pH (change from optimal can affect enzyme activity)

availability of inorganic ions (decreased nitrate ions decreased production of amino acids
reducing proteins reducing enzyme activity)

edaphic features
atmospheric humidity
wind speed

Question 9

Which gases are greenhouse gases

Answer 9

water vapour
carbon dioxide
nitrous oxide
methane
CFCs