nat 5: life of earth - all key areas

Alternative transcript:

- living biotic factors that affect the survival and food availability of species are, disease, grazing, predato protosynthesis what is photosynthesis? Green plants are capable of making their own food using energy from Sunlight and this process is called Photosynthesis word equation: carbon dioxide + water chlorophyll right 1 raw materials Stage Photosynthesis occurs in 2 Stages: Stage - light reactions uses light what is ATP? ATP is a high energy molecule and its how. energy is transported around the cell glucose + Oxygen 7 Products to produce hydrogen and ATP 2- carbon fixation a series of enzyme-controlled reaction which results in the production of glucose 292526 * the light energy from the sun is trapped by the chlorophyll (chioroplasts) and converted into chemical energy which is used to generate ATP (energy) 20 energy is also used to split water into hydrogen + oxygen 15 carb what is carbon fixation? fixation is a series of enzyme-controlled reactions. It involves the hydrogen from Stage one soining with carbon dioxide to produce glucose using ATP for energy * factors that affect the rate of photosynthesis: - temperature - light intensity carbon dioxide concentration oxygen light energy reaction ! light reactions carbon dioxide H ATP (carbon Fixation) reaction 2 KA3 water glucose * the chemical energy in glucose can be used by the plant in a number of ways - a source of energy from respiration" stored as starch Converted to cellulose energy, good production how is energy lost? energy is lost as heat, movement and undigested material a pyramid of numbers Shows the total number of organisms using fertilisers at each stage of the food chain - using pesticides example: Theron 8 Frogs 50 Slugs 200 Lettuces an irregular pyramid of numbers happens when the food chain involves a large producer or a para site example: Woodpecker insect * we can increase food yield (how much we produce) by :) Joak tree a pyramid of energy Shows the total available energy at each level in a food chain example: 3rd ✓consumer 0.1 10% 100% ← fertilisers can be natural (manure) or artifical (chemical) and they provide plants with nutrients such as nitrates, which helps the plants grow better and increases crop yield Pesticides are chemicals applied to crops to kill animals that eat the crop (Slugs) and plants that complete with the crop (weeds) and by removing these organisms the crop yield will increase Providing more food KA4+KA5 Eutrophication? Eutrophication is the ecosystems response to the addition of artifical or natural Substances such as nitrates, through fertilisers or sewage, to a water system By introducing pesticides into a food web you can upset the balance and reduce the bio- "diversity of an ecosystem 2nd consumer Producer GM crops GM crops are crops that have had their genetic info altered. these can be alternative to fertilisers and Pesticides Biological control Biological control Sinvolves using organisms suchas natural predators (or para sites to control pest numbers evolution what is a mutation? a mutation is a random change in genetic material. they may be neutral, advantage of disadvantage to survival factors that increase the rate of mutation. -radiation e.g. gamma rays, > x-rays or uv light Some chemicals Variation within a species there is usually a great deal of variation between individuals. variation within population makes it possible for a population to evolve (change) overtime in response to changes in the enviroment. this is called survival of the fittest Speciation Speciation is the formation of two or more species from an original ancestor lancestor finch linsect/ eating Iseed/ eating Natural selection natural Selection means the best adapted individuals survive (survival of the fittest) Selection pressures Selection pressures are disease or food avaiability factors such as predation that affects a population resulting in the death of Some individuals and the Survival of others Stages of speciation 1. a large interbreeding population 2. Splitting /isolation barriers 3. mutations 4. natural Selection 5. A new species formed a way to remember: I'M a New Species KAb Isolation Mutation Natural Selection what do isolation barriers do? Isolation barriers prevent gene exchange between different population types of isolation barriers: geographical = rivers, mountains, accons ecological = variations in temperature, water and availability behavioural = mating displays that don't attract other population