Bio 2A
- Created by: Shine.7
- Created on: 15-02-15 12:43
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- Bio 2A
- DIFFUSION
- spreading out of particles from an area of HIGH conc to area of LOW conc
- LIQ/GAS-particles free to move
- bigger difference in concentration,faster diffusion
- Rate of diffusion affected by: distance, surface area, concentration,temp
- CELL MEMBRANES: let stuff in n out. Dissolved substances can move by diffusion. ONLY very small molecules move through( Oxygen,Glucose,Amino,Water)
- Big molecules like starch+proteins dont!!
- particles move randomly so they go both ways: but if there's alot more on one side of the membrane= NET MOVEMENT (overall) from that side
- DISTRIBUTION
- TRANSECTS:study distribution along a line either count or use quadrat
- QUADRATS: place it at a random point and count organisms. Repeat and workout the mean. Repeat again and compare the two means.
- Mean: total/number of quadrats
- Population size: mean x total area
- RELIABILITY: large sample size-more representative
- VALIDITY: control all variables and use random samples
- Factors which affect organisms: availability of water,light,temp,nutrients,oxygen
- CELLS
- Yeast cell: single cell w/ n/cw/cm/cytoplasm
- Bacteria: ^ same but no NUCLEUS-floats
- 8 organelles: Nucleus Cytoplasm Cell Membrane Mitochondria Ribosomes Cell wall Vacuole Chloroplasts
- Specialised cells: palisade leaf cells/guard cells/red blood cells/sperm cell/root hair cell
- Muscular tissue: contracts to move
- Epithelial tissue: covers parts of body
- Muscular tissue: contracts to move
- Multicellular:consisting of many cells
- DIFFERENTIATION: cell becomes specialised for particular job
- similar cells: tissues different tissues:organ different organs:organ system
- Yeast cell: single cell w/ n/cw/cm/cytoplasm
- P.SYNTHESIS
- CO2+H20=sunlight=C6H12O6+O2
- Use for glucose: RCPSS
- PLANT TISSUES: Mesophyll tissue (photosynthesis occurs) Xylem+Phloem(transportation) Epidermal tissue (covers the plant)
- Chloroplast-chlorophyll-absorb sunlight-converts Co2-photosynthesis
- LIMITING FACTORS: light,Co2,temp,water
- Graphs: rate of psynthesis increases steadily//up to a certain point//graph flattens out=no longer limiting factor//other factors must be increased.
- Temp graph: too low: enzymes work slowly too high:denatured (45)
- Fair test(keep variable constant): Bench Lamp-control intensity of light. Water bath-keep temp constant
- DIFFUSION
- Measure how common an organism is in 2 areas
- study changes across an area
- Greenhouses: Temp in winter:heater Temp in summer: too hot-ventilation+shades Artificial light Co2- paraffin heater realeses Co2.
- ADV: plants free from pests+disease grow crops all year
- DIS: cost a lot+ waste if more is given to the plant than needed
- Glandular tissue: makes+secretes hormones+enzymes
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