Required Practical 10 Flashcards
(27 cards)
What is the aim of Required Practical 10?
Investigate the effect of an environmental variable on the movement of woodlice.
What type of response is being investigated in woodlice?
Kinesis.
What do woodlice do in an unfavourable environment?
They change direction more frequently and move faster.
Why do woodlice increase movement in unfavourable environments?
To find a more favourable environment, increasing their chances of survival.
What is used to demonstrate kinesis in woodlice?
A choice chamber.
How many quadrants are in the choice chamber?
Four quadrants.
What are the four types of environments in the choice chamber?
Dark and dry, dark and damp, light and dry, light and damp.
How is one half of the choice chamber made dark?
Use dark paper or cardboard.
How is one area made damp in the choice chamber?
Use wet paper towels.
How is one area made dry in the choice chamber?
Use a drying agent like anhydrous calcium chloride.
How many woodlice should be placed in the choice chamber?
10 woodlice.
What should be used to place the woodlice in the chamber?
A spoon.
Why should forceps not be used in the experiment?
Forceps may harm the woodlice.
How long should the woodlice be left in the choice chamber?
10 minutes.
What should be done after the 10 minutes?
Record the number of woodlice in each quadrant.
After recording the number of woodlice, what should be done next?
Move the woodlice back to the centre and repeat the process.
What is the biohazard in the experiment?
Contamination from live woodlice.
What safety precaution should be followed for handling live woodlice?
Wash hands after handling.
What statistical test can be used to analyse the results?
Chi-squared test.
What does the chi-squared test compare?
Observed results vs. expected results.
What happens if the chi-squared value exceeds the critical value?
You can reject the null hypothesis.
What does it mean if the chi-squared test shows a significant difference?
There is less than a 5% chance the results are due to chance.
What is the critical value used in chi-squared tests?
The 0.05 level of significance.
What environment do woodlice prefer in this experiment?
Dark and damp environments.
