Stomata of some plants are sunken and protected by hairs. These are features of
An ecological factor that will have the most limiting effects on the abundance of phytoplankton in a turbid pond is
In an experiment to determine the percentage of air in a soil sample, the following readings were recorded:
volume of water in measuring cylinder = 500 cm3
volume of soil added to water = 350 cm3
volume of water and soil after stirring = 800 cm3
the percentage of air in the soil sample is
A boy who is fond of swimming in a pond finds himself passing urine with traces of blood. He is likely to have contacted
The easiest way to establish the level of pollution in a local stream is to measure the level of
