BIOLOGY - CARB.S + POLLUTION TEST QNA Flashcards
What are the main causes of water pollution?
The main causes of water pollution are physical, biological and chemical pollutants. Water pollution can also be caused by things such as ocean and marine dumping, sewage and wastewater, etc. Sewage is the term for wastewater that often contains feces, urine, kitchen/laundry waste, etc.
How do fertilisers cause water pollution and explain how this affects water animals.
Fertilisers contain certain nutrients which help water plants to grow, for example algae. With the help of the nutrients, algae grows fast, then covers the surface of the water, and also dies fast. Its death causes the number of decomposers in that water body to increase. Thus, the decomposers use up oxygen as they carry out their job (of cleaning up the habitat) and the lack of oxygen causes the organisms to die. When fertilisers seep through the ground, they can also pollute the groundwater.
How can we test for the presence of starch in food
To test for the presence of starch in a food, we must add a few drops of iodine’s solutine into a boiling tube of water and starch (and mix it). Then, we will observe that the mixture changes to a blackish-blue color. Thus, this change of color proves that starch is present.
What is acid rain and how is it caused? What are the effects of acid rain on the environment, humans and buildings?
When fossil fuels like coal are burnt in industries, the gas nitrogen oxide or sulphur dioxide are produced. When these hot gases rise high into the air they mix in the air to form a weak acid (which precipitates and falls as acid rain). Plants and animals are harmed due to the acidity of the rain. Humans are as well. They face problems in health over time. Acid rain can corrode/eat away stonework or stone buildings.
Glucose - simple sugar
Starch - complex carbohydrate
Benedict’s solution - test for glucose
Iodines solution - test for starch
cellulose - found in plant cell wall
