➜ SKILLS TASK Biology Topic 4 Variation and classification Hi, my name’s Bex and I am an...

➜ 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

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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.


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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.


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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.


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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.


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Here I am taking my first sample from a nettle growing in the light.


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I carefully put each leaf into the bag.


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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.


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And again I am carefully placing them in my labelled bag for safe keeping.


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Now I have ten samples from each site.


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I have lined up the leaves from the nettles growing in the light and those growing in the dark. Which is which?


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Collect together your leaf samples, a notepad, pen, cloth and data table with headings. You also need a grid.


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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.


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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.


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Make sure you record the number of squares you counted straight away.


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Then, when you’ve finished you can wipe the dots off the grid, ready for the next leaf.


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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?


➜ SKILLS TASK Biology Topic 4 Variation and classification Hi, my name’s Bex and I am an...

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