All living things get energy from the SUN.
- Plants absorb some of the suns energy during PHOTOSYNTHESIS
- They store this energy in the chemicals that make up there cells
- Energy is transferred to other organisms when plants and animals are eaten or decompose
An ecosystem is an area containing a self-sustained community of organisms living in non-living surrounding e.g. a pond or a wood.
Within a ecosystem there are...
- Autotrophs - Self Feeders, they are also known as producers.
- Heterotrophs - also known as consumers
REMEMBER TO USE ARROWS IN YOUR FOOD CHAINS.
At each stage of a food chain, lots of energy is;
- Lost through heat or respiration
- Excreted as waste product
- Trapped in materials such as bone or fur
Percentage of energy transfer = Input energy / Output energy X 100
Pyramids of Numbers
- The feeding relationships between organisms in a food chain
- The total number of organisms that feed on each other in a food chain
The horizontal bars are called TROPHIC LEVELS
Pyramids of Biomass
More effective and accurate than pyramids of numbers.
Shows biomass of each organism
Biomass = dry mass
The biomass at each stage will be less than it was at the previous stage.
- BIOMASS - living organisms and decaying matter
- INORGANIC MATERIAL- rocks, stones and minerals
- AIR - for aerobic respiration
- WATER- contains mineral e.g. nitrates and phosphates
- Light energy absorbed by chlorophyll
- Light energy is used to rearrange the atoms of carbon dioxide and water to produce glucose.
- Oxygen is produced as waste product
Energy use in Plants
The glucose produced in photosynthesis is...
- Used in respiration to release energy for the plant so other chemical reactions can take place.
- It is converted into starch for storage
- Coverted into chemicals needed for plant cell growth e.g. cellulose, chlorophyll and protein
H.T - Plants normally absorb nutrients by diffusion, but the concentration of nitrates outside the plant is lower than the inside so a plant has to use ACTIVE TRANSPORT and use energy to absorb nitrates.
Glucose is stored in the from of startch so it doesn't upset the osmotic balance of the cell.
Limiting factors of photosynthesis
- Carbon Dioxide concentration
- Light intensity
Carbon dioxide traps heat radiation and prevents it from leaving the earth.
If the earths temperature keeps increasing the...
- Polar ice caps will melt
- Sea levels will rise
- Entire species will become extinct e.g. Polar bears :(
Mutualism- Both organisms benifit
Commensalism - One organism benifits, doesn't harm or benifit the other
Parasitism- Benificial to one organism (parasite), Harmful to the other (host)
- Suckers and teeth like structures to hold on to the intestine
- Very flat and long (more suface area to absorb food)
Sickle-Cell Anaemia is a disorder that affects the haemoglobin in red blood cells.
If someone has Sickle-Cell Anaemia, they have an abnormal form of haemoglobin which makes there red blood cells change until they become sickle shaped.They deprive the body's tissues and organs of oxygen.
Some symptoms of Sickle-Cell Anaemia:
- Feeling tired/weak
- painful cramps
- Eyesight problems
Inheritance of Sickle-Cell Anaemia
Sickle-Cell Anaemia is a hereditary disorder that occurs when a person inherits 2 faulty alleles.
2 faulty alleles - have the disorder
1 faulty allele - carry the disoder (may have some symptoms)
Sickle-Cell Anaemia and Malaria
Malaria kills people who have normal haemoglobin.
Sickle-Cell Anaemia creates abnormal haemoglobin.
If someone has Sickle-Cell Anaemia there is less chance that they will be affected badly by malaira