Microscopic Life In Water Flashcards
What are microscopic animals?
Zooplankton
What are phytoplankton capable of?
Photosynthesis and are producers in aquatic food chains and webs
Properties of plankton
- limited movement and so rely on water currents
- show seasonal variations in numbers due to variations in light, temperature and minerals
What can a variety and numbers of aquatic microorganisms be affected by?
Pollution and acid rain
What do pollutants of water include?
Oil, seawage, PCBs, fertilisers, pesticides and detergents
Explain the advantages of life in water
- no problem of water shortage and dehydration
- less variation in temperature
- more support
- easy disposal of waste products
Explain the disadvantages of life in water
- regulating water content
- resistance to movement
Explain the problems of water balance caused by osmosis?
Osmosis make it difficult for microscopic animals to balance eater.
Describe the action of contractile vacuoles in microscopic animals such as amoeba
Small vacuoles fuse into one large contractile vacuole, which empties the water out of the cell
What are the most common food webs in the oceans?
‘Grazing food webs’
What do some food chains rely on?
‘Marine snow’
Bacteria, deep in the ocean, acting as producers
What factors affect photosynthesis at different depths and in different seasons in water?
Light, temperature, minerals
Explain how sewage and fertiliser run-off can cause eutrophication
- rapid growth of algae
- resulting death and decay
- using up oxygen
- causing the death of animals unable to respire
Describe how certain species of organisms are used as biological indicators for pH and oxygen levels
Inset larva like mayfly or stonefly are very sensitive to changes in oxygen and can only survive in clean, oxygenated wayer. Other insect larva, e.g, bloodworms have specials adaptations to survive in polluted, deoxygenated water
Explain the accumulative, long term effect of PCBs and DDT on animals such as whales
If these chemicals are eaten they cannot be broken down but are stored in fat in the body. At each feeding level the chemicals accumulate in the tissues of the animals.
