➜ SKILLS TASK Biology Topic 4 Variation and classification Hi, my name’s Bex and I am an Environmental Science student. This means I use biology, chemistry and physics to study the environment. Nettle leaf investigation Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Fieldwork to collect and analyse data on nettle leaves ➜ I decided to take some measurements to find out if nettle leaves in sunshine are smaller than nettle leaves in the shade. ➜ You are going to do this too. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification I noticed that the leaves are bigger lower down the plant. So I need to make sure that I sample the leaves at the same point on all the nettle plants. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification I decided to sample the seventh leaf down from the top each time. You can see the one on the centre stem is just above my finger. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification I’ve got gloves to protect my hands, secateurs to cut the leaves and labelled bags so I will know which site my leaves have come from. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Here I am taking my first sample from a nettle growing in the light. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification I carefully put each leaf into the bag. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Now I’ve got all ten leaves from the light, I’ve come down to the edge of the wood to take samples from the nettles in the shade. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification And again I am carefully placing them in my labelled bag for safe keeping. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Now I have ten samples from each site. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification I have lined up the leaves from the nettles growing in the light and those growing in the dark. Which is which? Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Collect together your leaf samples, a notepad, pen, cloth and data table with headings. You also need a grid. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Take each leaf in turn and place the grid over your leaf. You need to count the number of squares covering your leaf. I’ve put a dot in mine so I know which squares I’ve counted. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Sometimes the leaf doesn’t fill a square, so I’ve decided only to count squares where the leaf covers half or more. It doesn’t really matter as long as you are consistent. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Make sure you record the number of squares you counted straight away. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Then, when you’ve finished you can wipe the dots off the grid, ready for the next leaf. Science Progress © Hodder & Stoughton 2014

➜ SKILLS TASK Biology Topic 4 Variation and classification Analysing and showing the data from the nettle leaves ➜ You need to do this until you have counted the area of all your leaves both from the sunlight and the shade. ➜ Now calculate the average number of squares for the leaves that grew in sunlight. ➜ Calculate the average for the leaves that grew in shade. ➜ Are sunlight or shade leaves larger on average? Science Progress © Hodder & Stoughton 2014