Energy Flow Flashcards
Reasons for drawing ecological pyramids
To analyze the relationship between tropic levels in a ecosystem
Differentiate between energy flow and nutrient cycle.
Energy flow is the transfer of enegy through the trophic levels in a non cyclic, unidirectional way. Nutrient cycle is the cycling of nutrients and minerals through living organism and the environment.
The source of enegry comes from the sun for energy flow while the source of nutrients for nutrient flow comes from the lithoshpere and atmosphere.
Loss of energy as heat is observed in energy flow as enerfy is transferred up the trophic levels. In nutrient cycle, all the nutrients are reuse and recycled and none is lost as heat.
The roles of decompsomers in energy flow is the release energy as heat to the environment while decompers in the nutrient cycle are responsible for releasing the nutrients from the compound to be recycled.
Differentiate between habitat, ecosystem and ecological niche
A habitat is the specific location where an organism lives while an ecosystem is a self contained area where a community lives and the interactions between themselves and the environment. Ecological niche is the role a species has
How is energy lost in food chains?
Photosynthesis, Respiration, heat and dying
What is the difference between a food chain and food web?
food chain shows a singular pathway in which energy is transferred in a ecosystem while a food web shows multiple food chains connected.
Why do plants only use 3% of sunlight?
- Majority missed the plant completely and falls to the ground
- Some light is reflected off the surface of the plant leaves.
- Some light passes throught the leaves without being absorbed by chlorophyll.
- Only light of a certain wavelenght is absorbed.
Limitations of pyramid or energy
- Time consuming
* Suggest that consumers feed on the trophic level below them
Describe the relationship between top predators and energy flow.
Top predators must feed from different trophic level to gain maximum energy. Since energy transfer is so ineffiecnt, by the time it reaches the 4th or 5th trophic level, little energy will be left for top redators that only feed from the trophic level beneath them. Top predators that only feed on the trophic level beneath them is more likely to go extinct.
Describe how nitrogen is cycled in the ecosystem.
Step 1: Nitrogen fixation- N2 in the atmosphere is converted to ammonia NH4 by rhibozium.
Step 2: Nitrification- NH4 is converted to nitrite (NO2) by nitrosomos and then nitrate (NO3) by nitrobacter.
Step 3: Ammonification- Waste from animals and dead bodies are converted to NH4 by ammonifying bacteria.
Step 4: Assimilation- The process by which plants take up nitrates and use it for metabolic processes.
Step 5: Denitrification- Nitrate to N2
How are ecosystems self sustaining units?
Because of energy flow and nutrient cycling. Energy flow allows for energy to be transferred up the tropic levels. The source of energy is the sun which only plants can translate of chemical energy, hence energy is always available. Nutrient cycle allows for nutrient to be recycled and never lost as heat.
Disadvantages of Pyramids of Biomass
- Portions of biomass that is not transferred may be counted. Eg, hair, beak, feathers.
- Some for eaten might not be digested and hence cannot be transferred to the next tropic level.
- They do not show changes over periods of time
What are some disadvantages of pyramids of numbers?
- There can be in inverted if produces are large eg, trees, that support hundreds of primary producers
- Microorganisms are not considered even through they are important to ecosystem.
- Results rely on estimated figures from sampling
- Only shows result for a certain moment in time
Briefly describe the 3 ways N2 is introduced to the ecosystem
1: Bacteria- Rhizobium converts N2 to NH3 or NH4
2: Lightning- Lightning contains the high energy needed to break the triple bonds of nitrogen to make NH4
3: Haber Process- H2 and N2 are combined to the from NH3 for fertilizers
What are the advantages of food webs
Food webs always for multiple sources of food. food webs are a better indication of feeding relationships in the ecosystem and provided a better analysis of the food culture of an organism
Why is it impossible to get an inverted pyramid of energy?
Only a fraction of the energy is available to the next tropic level. The energy is always lost so energy will always decrease and hence, pyramid cant be inverted. Second law of thermodynamics
