Experiments in the core topics (1 Viewer)

[Brontecat]

Since I only began HSC Bio at the start of last term i missed out on doing pretty much all of the experiments. These are the ones that i just do not understand, basically the ones i couldn't make up stuff for.
It would be really, really helpful if anybody could answer some of these, even if you only answer one.
Thanks

Maintaining a balance

perform a first-hand investigation to demonstrate the effect of dissolved carbon dioxide on the pH of water

Blueprint of Life

identify data sources and perform a first-hand investigation to demonstrate the effect of the environment on phenotype

perform a first-hand investigation or process information from secondary sources to develop a simple model for polypeptide synthesis

Search for better health

identify data sources, plan and choose equipment or resources to perform a first hand investigation to identify microbes in food or in water

 

[sam5]

Since I only began HSC Bio at the start of last term i missed out on doing pretty much all of the experiments. These are the ones that i just do not understand, basically the ones i couldn't make up stuff for.
It would be really, really helpful if anybody could answer some of these, even if you only answer one.
Thanks

Maintaining a balance

perform a first-hand investigation to demonstrate the effect of dissolved carbon dioxide on the pH of water

Blueprint of Life

identify data sources and perform a first-hand investigation to demonstrate the effect of the environment on phenotype

perform a first-hand investigation or process information from secondary sources to develop a simple model for polypeptide synthesis

Search for better health

identify data sources, plan and choose equipment or resources to perform a first hand investigation to identify microbes in food or in water

The first one can be done by getting a beaker of water and adding universal indicator to it. A person should get a straw and blow bubbles into the water. Slowly, it should be observed that the water will turn colour from green to orange/yellow. Because it is known that acidic solutions containing universal indicator will be yellow, orange or red, we can conclude that carbon dioxide will acidify the blood (water makes up 90% of blood plasma, 55% of blood is plasma). There is a chemical reaction that occurs. CO2 + H2O --> H2CO3. H2CO3 is carbonic acid.

We didnt do the second one. You could look this up in a textbook or on the hsc online csu website. What you are looking at is how organism's characteristics can be altered when exposed to different environmental conditions. Im sure u can relate this to Darwins theory, but u must be able to think of an experiment. (just as a thought, you could do the effect of pH on flower colours, cos i know that some flowers on plants will be different colours depending on the pH of the soil).

Our third one was really lame. We used paper, scissors, rulers, pencils and glue to create models. You can describe a process for making the models with these simple materials, and include a little discussion of benefits and problems with using scientific models for teaching purposes.

The last one can be done by getting an aqueous food sample or water samples and wiping the samples onto agar plates, which are put in an incubator at 35 degrees for a few days. The microbes that grow can be noted and possiblyclassified or identified under a microscope.

When u do these types of questions, always discuss things like sample size (as large as possible), repetition, validity, data reliability and gathering, dependent and independant variables, risk assessment, waste management and control groups.

Hope that helps.