Visiting Scientist

This afternoon Dr Anna Chapman (Sam's mum!) visited R12 as our resident scientist to teach us all in her area of expertise. We love it when parents come in to help and share our learning with us.

She talked about

• transpiration (plant perspiration)
• CO2 (energy)
• photosynthesis
• plants getting energy from the sun and releasing H2O as a gas
• hypotheses
• control

We began with a simple experiment looking at the environmental effects on plants. We measured weights of plants and will repeat this again in 24hrs to see how much water the plants have lost through transpiration.

We are getting the hang of being REAL scientists because we love asking lots of questions!

Dr Chapman helped us understand how to write up a proper record of experiments, these usually go in a lab book.

17/9/2013     TRANSPIRATION EXPERIMENT

Aims:  - To determine water loss in Primula plants / To investigate how much water Primula plants lose.
            - To determine the effects of light, darkness, wind and humidity on Primula plants.

Hypotheses: - The plant in the light will lose more water
                      - The plant in the dark will lose less water
                      - The plant in the wind will lose more water
                      - The plant in the humid conditions will lose less water 

Method:
Materials: 5 Primula plants
                 water
                 light
                 cupboard
                 fan
                 plastic bag
                spray bottle
                scales

1. Weigh and record weight in grams (g) and millilitres (ml)     (1g = 1ml)
2. Set up our variables a) darkness, plant placed in closed cupboard

                                          b) light, plant placed in front of light
                                          c) wind, plant placed in front of fan
                                          d) humidity, plant placed in plastic bag sprayed with H2O
                                          e) control, plant placed away from other environmental conditions, in a                                          neutral location

Our plant under the light

Wind

 Darkened cupboard (once Ms Saxon closes the door!)

Results:
Condition        Weight (g)
                         t=0 (hr)     t=23(hr)     H2O loss (ml)

Control             548            509              39

Light               542              502              40

Darkness         569              530              39

Wind * 7hrs    548             499              49

Humidity         564             563               1


We have set these plants up overnight and will re-visit them tomorrow and re-weigh.

Wednesday
The plants gave up a few odd results. We were surprised that the Primula in the light (which looked really dried out!) had only lost the same amount of water as the control and dark plants. We thought the plant in humidity didn't lose much water because it had a moist environment that it was in.

The children now graphed the results on a bar graph. 

Conclusions:  
 1. The plant placed in humidity lost only 1ml of water. 
2. The plant placed in the wind lost more water than the control. 
We predict that if the plant had been in the wind for 23hours it would have lost even more water. 

3. We expected that the plant placed in the light to lose more water than the control and the plant in the dark to lose less, but they lost the same amount. We think this is because the pots were too small. 

A huge thanks to Dr Chapman, we love having parents coming in to share their expertise with us. Anna has offered to come in regularly next term and do 'cool' science experiments with Room 12 - we are very excited!!!