Organisms in the environment (photosynthesis + distribution) Flashcards
What colour does iodine turn when it reacts with starch?
Blue/black
What happens if glucose produced by photosynthesis is not immediately used for respiration?
It is converted into insoluble starch (using energy from respiration) and stored; build it up into cellulose; making amino acids; build up fats and oils
Adaptations of leaves?
Broad - large surface area; chlorophyll - absorb light for photosynthesis; air spaces -carbon dioxide to get to cells and oxygen to leave by diffusion; veins - bring water
How does temperature affect photosynthesis?
Increases it, until enzymes denature at about 40-50 C
How are amino acids made in a plant cell?
Combining sugars with nitrate and other mineral ions, using energy from respiration
What might fats and oils (made from glucose from photosynthesis) be used for?
Energy store in cells; strengthening cell walls; store in seeds, providing energy during germination
Why is starch made for storage instead of leaving it as glucose?
Starch is insoluble so doesn’t affect osmotic pressure
Where and why might starch be stored?
For when light levels are low i.e. in winter and in tubers and bulbs for some plants
What is hydroponic growth?
Growth using artificially balanced mineral ion solutions instead of unpredictable soil
What factors affect the distribution of animal organisms?
Temperature - enzyme activity; nutrient availability; light - eat plants - breeding cycles linked to day length i.e. different in winter to summer; water availability; oxygen and carbon dioxide availability - only for aquatic animals
What is quantitative sampling?
Taking a number of random readings and then finding the mean
When would one favour the use of random quadrat sampling over transect sampling?
If one is measuring the distribution of plants in a specific area, rather than over a range of habitats
