B4 Flashcards
What does an ecosystem consist of?
The living organisms together with the physical conditions in an area.
What’s a community?
All organisms (different species) living in a habitat.
What’s a habitat?
Place where plants, animals, microorganisms live
What’s the defenition of population?
All organisms of 1 species in a habitat
What are producers?
Organisms that make thier own food, usually first trophic level.
How’s energy transferred between organisms?
- Energy transferred to chlorophyll by light in producers
- CO2 reacts with H20 to make glucose, that stores energy in chemcial bonds
- Some glucose used, rest converts to carbs, fats, protein, this is used to grow. As it grows biomass increases
- Energy transferred to consumers as it gets eaten
- When respiration occurs, energy in food converts to ATP
What does the arrow in food chain represent?
Biomass or energy transfer
What are biotic factors?
Living factors of an ecosystem
What are abiotic factors?
Non living factors (physical) factors of an ecosystem
What are the main abiotic factors that affect communities?
- Temperature
- Moisture level
- Light intensity
- Soil pH
How does temperature affects communities?
- It greatly affects enzyme controlled metabolic reactions
- Plants develop faster in warmer conditions as metabolism is faster
- Cold-blooded animals (ectotherms) rely on heat from sun for heat, warm blood (endotherms) less affected
How does the light intensity affect communities?
- Light required for photosynthesis, more light, more sucess or growth of plant
- Plants evolve fro different light conditions, low light, wider leaves
- if too little light grass can be replaced with fungi, moss that are better able to cope with low light intensity
How does moisture level affect communities?
- Lack of water causes death
- Lack of water in plants causes cells to wilt as no water to keep cells turgid, plant falls down
How does soil pH affect communities?
-Affects biological activity, some plants grow better in acidic or alkali conditions
Why do organisms compete?
- Organisms require materials
- If materials are limited, they are competed for, weaker species end up dying
What do plants need to survive?
- Light -Minerals
- Water -Space
- Carbon dioxide
What do animals require to survive?
- Food -Shelter
- Water -Territory
- Mates
What is something that has a direct impact population?
Competition
What’s interdependance?
How organisms in a community depend on each other
What are the interactions between organsism known as?
Ecological relationship
What are the 3 types of ecological relationships?
- Predation
- Mutualism
- Parasitism
Whats predation?
Relationship between predatorand prey species. Prey population directly affects predator population.
predator goes up, prey goes down
Why are prey-predator cycles out of phase?
It takes a while for one of each to respond to changes of other
Whats mutualism?
Relationship where both organisms benefit
Whats an example of mutualsim?
Nodules legume plants, contain nitroogen-fixing bacteria providing plants with nitrates and get sugars in return
Whats parasitism?
Relationship where only one organism gains, parsite gains, host organism loses
What does a biomass pyramid show?
It shows the flow of biomass through a community
Why is a biomass pyramid in the shpae of a pyramid?
Biomass reduces as it cant all be trasferred, so less gets transferred each trophic level
Why do scientists calculate dry mass of an organism?
Because waterweight varies between organisms making the average weight not accurate
How is the gluose thats made from photosynthesis used?
- Some glucose instantly used in respiration
- Rest of glucose used to make biological molecules, like cellulose
- The biological molecules store energy helping plant grow thus increasing plants biomass
Why is not much biomass transferred to the next trophic level?
- Animals use some biomass for respiration, to keep warm and help movement
- Biomass is lost through excretion(sweating, urinating, breathing out)
- Biomass is lost through egestion, getting rid of undigested food as faeces.
Why do food chains usually contain max 5 trophic levels?
Somuch biomass is lost at each stage there isn’t enough to support organisms after a certain stage
