OCR Biology A Level
Biology
flashcards based off the specification for all of ocr biology a level
Sample Data
| Front | tropisms |
| Back | -are a response to a directional stimulus-plants respond by regulating growth, positive tropism is towards the stimulus and negative is away from the stimuluse.g.phototropism,geotropism,hydrotropism(water-roots positivley), thermotropism,thigmotropism(contact with an object)-plants respond using growth hormones (produced in growing regions and move to where needed) |
| Front | counter-current system in fish |
| Back | blood flows through gill plates in the opposite direction to water, maintains a large concentration gradient-concentration of oxygen in water is always higher than in blood so as much oxygen diffuses (equillibrium would be reached without)
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| Front | need for transport systems |
| Back | -multicellular organisms have low SA:V ratio+higher metabolic rate+more activity(more respiration), all cells need good supply so transport systems needed e.g.circulatory system |