Biogeochemical Cycles
Which gas do plants take in during photosynthesis?
Carbon dioxide (CO₂)
What is the first species to grow in an area during primary succession called?
Pioneer species
What does it mean if an animal is nocturnal?
It is active at night and rests during the day.
What is the main energy source for almost all ecosystems?
The Sun
in the nitrogen cycle, what organisms change nitrogen gas into forms plants can use?
Nitrogen-fixing bacteria
What type of succession happens after a forest fire — primary or secondary?
Secondary succession
Why do many nocturnal animals have large eyes and pupils?
To allow more light to enter for better night vision.
Which process recycles water through evaporation, condensation, and precipitation?
The water cycle
What is the process called when water changes from a liquid to a gas?
Evaporation
In primary succession, what type of surface does life start on?
Bare rock
Give one example of a nocturnal predator and its prey.
Owl and mouse.
During secondary succession, what allows life to return faster compared to primary succession?
Soil is already present with seeds and nutrients.
Explain how the burning of fossil fuels affects the carbon cycle.
It releases extra carbon dioxide into the atmosphere, increasing greenhouse gases.
What is the final, stable community called at the end of succession?
Climax community
Besides sight, name two other senses nocturnal animals rely on and explain why.
Hearing and smell — they help detect prey or predators in darkness.
Why might nocturnal animals be more active in cooler nighttime temperatures in the desert?
To avoid losing water and overheating in the hot daytime sun.
Some nocturnal animals, like bats, don’t rely on sight at all to find prey. What adaptation allows them to navigate and hunt in complete darkness, and how does it work?
Echolocation — they emit high-frequency sounds that bounce off objects, and the returning echoes help them locate and identify objects or prey.
Describe one major difference between primary and secondary succession in terms of soil.
Primary begins without soil; secondary starts where soil already exists.
How do plants and animals each play a role in the carbon cycle?
Plants take in carbon dioxide during photosynthesis to make food, and animals release carbon dioxide back into the atmosphere through respiration.
Describe how a forest fire can impact both the carbon cycle and ecological succession at the same time.
Burning trees releases carbon dioxide into the atmosphere (carbon cycle) and starts secondary succession as new plants grow on the burned land.