How to Answer Biology

7/31/2019 How to Answer Biology

1/14


2/14

Question 2.

Human factor is found to be the biggest waterpolluter in our country. Domestic waste and

organic waste are disposed off indiscriminatelyinto our rivers. A group of university studentshave undertaken the task of finding out the levelof water pollution from two different sources.


3/14

Design an experiment to help these students todetermine the range of pollution levels of tap waterand the river water from town A.

Your experimental planning must include thefollowing aspects:

Problem statement

Aim of experiment Hypothesis Variables List of materials and apparatus

Technique used Procedure Presentation of data Conclusion


4/14

Must be in a question form.

What is the level of pollution of tap water and the river water?


5/14


6/14

Able to state the hypothesis correctly based onthe following criteria:

State the manipulated variable

State the responding variable

Relate the manipulated variable and theresponding variable

The time taken for the indicator to decolorized in riverwater is less than tap water.


7/14

Write down all 3 variables ( one for eachvariable )

Manipulated: Type of water sourceResponding: Time taken for the indicator to decolorizedControlled: Volume of different water sample used


8/14

In a complete sentence, write down what isobserved or measured (include the instrumentused). State the specific name of the technique

where applicable. Example : ( i ) Measure and record the volume

of fruit juices needed to change the blue DCPIPto colorless using a syringe.

Record the fastest time taken for the methylene blue solutionto decolorize using a stopwatch


9/14

List down at least 3 materials and 3 apparatus .

Sample of tap water , sample of river water, methylene bluesolution, beakers, reagent bottles, bottle stoppers, syringeand stopwatch.


10/14

Write down each step clearly and

systematically (include precautionary steps) .

1. Two reagent bottles are filled with 100ml of tap water and100ml of river water.

2. The reagent bottles are closed with the bottle stoppers.3. 1 ml of 0.1% methylene blue solution is added into the

sample water. The indicator is inserted using a syringewithout shaking the reagent bottle.

4. The reagent bottles are kept in a dark cupboard and

stopwatch is started.5. Observations are recorded for every hour until the blue

color turns colorless.6. Time taken for the change in color to take place is recorded.


11/14

Construct the table with the correct titles(manipulated and responding) and units(results no need) .

Sourceof

water

1hour

2hours

3hours

4hours

5hours

6hours

Tapwater

Riverwater


12/14

Must write hypothesis is accepted / rejectedand repeat or modify the hypothesis sentence.

The time taken for the indicator to decolorized in riverwater is less than tap water. River water is more pollutedthan the tap water. Hypothesis is accepted.


13/14


14/14

How to Answer Biology

Documents

Transcript of How to Answer Biology