Transcript Skills task - Nettle leaf investigation

➜ SKILLS TASK
Nettle leaf investigation
Hi, my name’s Bex and I am an Environmental
Science student. This means I use biology,
chemistry and physics to study the environment.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
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.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
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.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
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.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
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.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
Here I am taking my first sample from a
nettle growing in the light.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
I carefully put each leaf into the bag.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
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.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
And again I am carefully placing them in my
labelled bag for safe keeping.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
Now I have ten samples from each site.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
I have lined up the leaves from the nettles
growing in the light and those growing in
the dark. Which is which?
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
Collect together your leaf samples, a
notepad, pen, cloth and data table with
headings. You also need a grid.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
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.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
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.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
Make sure you record the number of
squares you counted straight away.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
Then, when you’ve finished you can wipe
the dots off the grid, ready for the next leaf.
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK
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?
Biology Topic 4 Variation and
classification
Science Progress © Hodder & Stoughton 2014