7 Ecology Seperate Flashcards
State the three environmental factors that can cause a change in the distribution of organisms.
Water availability, temperature, (dissolved) atompsheric gases concentration
Give three possible reasons to changes in environmental factors.
Seasonal changes, geographical changes, result of human interaction
Suggest one positive change on the environment due to human interaction.
Maintain rainforests / Reduce water pollution and monitor pH / Restrict entry to protected areas / Conservation measures
Suggest one negative impact on the environment due to human interaction.
Global warming and climate change / Acid rain / Pollution
Suggest how organisms may adapt to seasonal changes.
Migrate to areas with more ideal conditions
Define ‘trophic level’.
Position of organisms within a food chain
What kinds of organisms are in trophic levels 1 and 4 respectively?
1: Producers; 4: Tertiary consumers
State the name given to carnivores with no predators above their level.
Apex predators
How do decomposers break down organic matter?
Secrete enzymes into the environment –> absorb small soluble food molecules back in through diffusion
What needs to be done to an organism in order to measure its biomass?
Kill it + dry them out
What is a problem with measuring wet biomass?
Water levels vary throughout the day and dependent on conditions –> less repeatable results
State the original source of all biomass.
Photosynthesis
Which trophic level is always at the bottom of the pryamid of biomass?
Trophic level 1 (producers)
What happens to the amount of biomass at each trophic level as we go up the food chain?
Decreases
Give three reasons why biomass always decreases as we go up the trophic levels.
- Not whole/part of organisms are eaten; 2. Some biomass taken in is passed out and lost as waste; 3. Most biomass taken in is used up in respiration, only some used to build new biomass
What is incident energy?
All the energy from the sunlight falling on Earth
Approximately how many percent of the incident energy is used by producers to do photosynthesis?
1%
Approximately how many percent of the biomass from each trophic level is transferred to the next?
10%
Why cannot herbivores digest all the plant material they eat?
Most herbivores lack enzymes to digest cellulose
Why cannot carnivores eat all of their prey?
Some parts are impossible to digest (eg. bones, claws)
What is made from excess amino acids to be excreted as waste?
Urea
What are the three waste products from respiration?
Carbon dioxide, water, heat
Explain why the more movement an animal does, the more biomass it loses.
More movement requires more respiration to provide more energy for muscle contraction, hence less biomass available to build new biomass
Explain why mammals need to eat more food than amphibians to achieve the same increase in biomass.
Mammals need to use biomass constantly to maintain body temp regardless of surroundings, whereas amphibians can change their body temp according to surroundings, so for them more biomass is used to build new biomass (less wasted compared to mammals)
State the four ways in which biomass can be lost from an animal.
- Through faeces; 2. Through urine; 3. To provide energy for movement; 4. Heat loss from respiration to surroundings
What is meant by ‘food security’?
Having enough food to feed a population
State a consequence from low or lack of food security.
Malnutrition/starvation
State three factors that affect food security.
Increasing birth rates / Changing diets / New pests and pathogens affecting farming / Environmental changes affecting food production / Cost of agricultural inputs / Conflicts affecting access to food and water
How can a change of diet in developed countries threaten food security?
More scarce food resources delivered to developed countries, depriving local people (usually in developing countries) of their food source
How does climate change affect farming?
Droughts and flooding destroy crops and damage farmlands (no fertile soil)
What is sometimes fed to livestock to increase their growth?
High protein food (eg. other animals)
Why would reducing the stages in the food chain dramatically increase the efficiency of our food production?
Less biomass/energy lost
State two methods farmers use to increase the efficiency of food production.
- Limit animals’ movement; 2. Control temperature of surroundings
Explain why limiting livestocks’ movement could improve the efficiency of food production.
Less movement hence less biomass used up in respiration for muscle contraction
Explain why controlling the temperature of the surroundings can improve the efficiency of food production.
Less biomass used in respiration to maintain body temperature
Suggest a disadvantage to limiting livestocks’ movement.
Risk of disease spreading quickly
What is meant by sustainable food production?
The idea to produce food that ensures there is still good quality food available for future generations
What is the problem with overfishing?
No more younger fish to grow and reproduce to replace them in the future –> low fish stocks
Describe two ways to conserve fish stocks at a sustainable level.
- Control net sizes (larger); 2. Introduce fish quotas and season bans
What is the role of biotechnology in food production?
Culture genetically engineered microorganisms to produce large quantities of food
What is mycoprotein?
Protein made by fungus
Name the fungus that can be used to produce mycoprotein.
Fusarium
What are the two requirements for the fungus to grow to produce mycoprotein?
Glucose syrup + Aerobic conditions
State an advantage in using fungi as a renewable food source.
Cheap raw material to feed fungi / Reproduce rapidly
State an advantage in using genetically modified crops.
Provide more food / food with better nutritional value
