Equipment required: One or more buckets of water (or access to a garden hose connected to a water supply). Pour one or two buckets of water (or run water from a garden hose) on bare ground (grass or soil is OK). Observe how the water moves. Some of the water may soak into the ground and some may flow over it. Pour a few more buckets (or run more water from the garden hose) over the same area and observe any differences in the behavior of the water. Does it still soak into the ground? Discuss how the moisture conditions in the soil will affect how much water gets absorbed. Would water be more likely to run off after the ground has been saturated by a heavy rainstorm? Discuss what happens to the water that gets absorbed into the ground.

Repeat the demonstration on a paved surface such as a driveway or sidewalk and document the differences. With no soil to absorb this water, what would happen in a heavy rainstorm? How would an engineer in charge of a city’s flood control system prepare for the runoff generated on paved parking lots and roads in a heavy rainstorm?

No water will be soaked by the soil if it has saturated condition.

Explanation:

If the soil does not reached to its saturated point so the soil will soak the water while on the other hand, if the soil reached to its saturated point so it will not absorb the water. If soil has more water so it will not be able to absorb more water. Yes, water will be more likely to run off after the ground has been saturated by a heavy rainstorm and the water absorbed by the soil remain in the soil for the plant while the large quantity of water percolates down and reach the water table. With no soil to absorb water, the water goes to rivers and streams when a heavy rainstorm held. The engineer has to built a well drainage system in order to remove runoff water from the roads and pavement and avoid flood condition.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: