(outdated) Ecology
99 questions· page 1 of 10
Which soil would have the smallest number of denitrifying bacteria?
Options
A compressed agricultural soil
B poorly drained forest soil
C water-logged clay soil
D well-aerated garden soil
In an ecosystem, at which stage is most energy lost?
Options
A sunlight trophic level 1
B trophic level 1 trophic level 2
C trophic level 2 trophic level 3
D trophic level 3 trophic level 4
Two species of animal are found in the same area of forest and grassland. In the spring and summer they eat the same plant food. However, in the autumn and winter one eats nuts in the forest and the other eats roots on the grassland.
Both species are preyed upon by the same predator. Numbers of root-eating animals are reduced most by this, but they recover faster since they reproduce faster.
What can be concluded about these two species of animals?
1 They are part of the same community.
2 They are at different trophic levels.
3 They occupy different habitats.
4 They have different niches.
Options
A 1, 2 and 4
B 2, 3 and 4
C 1 and 2 only
D 1 and 4 only
At which stage of a food chain in a tropical grassland is the energy transfer least efficient?
Options
A A
B B
C C
D D
A farmer grows a different crop in a field each year for three years.
In the fourth year he grows a leguminous crop, such as clover, and then ploughs this into the soil. The next year he starts the rotation again.
How does the fourth year crop add mineral ions to the soil?
Options
| decomposition | nitrification | nitrogen fixation | |
|---|---|---|---|
| A | no | yes | yes |
| B | yes | no | yes |
| C | yes | yes | no |
| D | yes | yes | yes |
Of the prey consumed by the lion, into which box does the largest amount of energy go?
Options
A energy lost in urine
B energy used in growth, repair and reproduction
C energy lost as heat from respiration
D energy lost in faeces
The diagram represents part of the nitrogen cycle.
Which process is carried out by nitrifying bacteria?
Options
A A
B B
C C
D D
A primary consumer, X, is lost from a community due to a lethal viral infection.
After a time, the size of the populations of some of the organisms shown in the food web changed.
Which population of organisms increased?
Options
A A
B B
C C
D D
The table shows the results of a field study of four species in a food chain in an area of woodland.
| species | number of individuals | biomass of one individual / arbitrary units | energy value per unit mass / arbitrary units |
|---|---|---|---|
| P | 10000 | 0.100 | 1.0 |
| Q | 5 | 10.000 | 2.0 |
| R | 500 | 0.002 | 1.8 |
| S | 3 | 300 000.000 | 0.5 |
Which is the correct pyramid of energy from these data?
Options
A tree carries out photosynthesis and provides organic compounds for other organisms in a forest.
It takes carbon dioxide from the atmosphere and returns oxygen to the atmosphere.
It takes water from the soil into its roots and its leaves lose water to the atmosphere.
Many other organisms live in the tree.
Which term describes the tree?
Options
A population
B community
C ecosystem
D trophic level