Ecology and the environment

Written by Dr. Hira Salman (Biology)

MDCAT · Biology · 6 questions

Name: ____________________ Date: ____________

Primary succession begins on:
- A Bare rock with no soil
- B An abandoned field
- C A forest after a fire
- D Fertile farm soil
Which process returns nitrogen from the soil to the atmosphere?
- A Denitrification
- B Nitrogen fixation
- C Nitrification
- D Ammonification
A relationship in which both organisms benefit is called:
- A Predation
- B Parasitism
- C Mutualism
- D Competition
Which biome has permanently frozen soil called permafrost?
- A Tundra
- B Desert
- C Savanna
- D Tropical rainforest
A population with unlimited resources grows with a:
- A Sigmoid curve
- B Flat line
- C Falling curve
- D J-shaped (exponential) curve
Which group of chemicals is mainly responsible for damaging the ozone layer?
- A Chlorofluorocarbons (CFCs)
- B Carbon dioxide
- C Nitrogen
- D Methane

Answer key

1. A, 2. A, 3. C, 4. A, 5. D, 6. A

Primary succession starts where no soil exists, for example on bare rock, and pioneer species such as lichens come first.
Denitrifying bacteria convert nitrates into nitrogen gas.
In mutualism, both partners gain, as with a legume and its root nodule bacteria.
Permafrost is characteristic of the tundra.
Without limits, a population grows exponentially, giving a J-shaped curve.
CFCs release chlorine atoms in the stratosphere, and these break down ozone.