Slaters Investigation Report

AS91601 Final Report

Carry out a practical investigation in a biology context, with guidance.
Name : Olivia Nilson

Introduction

Slaters (woodlice or porcellio scaber) are often found in gardens. They usually like to hide in cool moist dirt or in cold places such as under pots or bricks

Aim : To investigate how temperature affects the speed of slaters
Hypothesis : I predict that the slaters will move faster when the temperature is increased, above their preferred temperature range, as they try to find a way out of the unfavourable conditions using negative thermokinesis

Independent Variable

The variable that I will be changing it temperature. I will need to use at least 4 different temperatures in order to make a valid conclusion. The
I will try to use a similar sized Slater each time because if we use super small ones or super large ones then they might move at different speeds which will skew the trials. I will also use Slaters that have been kept in the same environment so they will hopefully react the same way to a change in temperature.
My last controlled variable is measuring. I need to make sure I start timing at a specific point and have an easy way or measuring how far the slater travels. This will be hard to keep consistent because the slater will be constantly moving.

Method

Equipment : A 200ml beaker, a petri dish, an ice cream container, 10-20 slaters (of a similar size), a stopwatch, a temperature probe, hot water, ice, ruler

1) Collect all the equipment
2) Fill the ice cream container with cold water and use ice to get it down to 10-14°C
3) Place the beaker in the water bath and allow it to cool to the temperature of the bath, using the temperature probe to measure the temperature inside of the beaker
4) Place a slater inside the beaker and allow it to get used to the new
Then measure the distance from the start point to where the slater finished and add that distance to the previous calculation
8) Remove the slater from the beaker, leaving the beaker in the water bath
9) Check the temperature of the water bath and if it isn’t 10-14° C add more ice until it is back in the required range again
10) Repeat steps four to nine at least nine more times until you have 10 sets of data which contains no outliers
11) Repeat steps four to ten except with the water bath at 15-19°C
12) Repeat steps four to ten except with the water bath at 20-24°C
13) Repeat steps four to ten except with the water bath at 25-29°C
14) You now have 10 sets of data for each of the four temperature ranges so use your data and the formula v(speed) = d(distance)/t(time) to find the speed of the slaters