Download B1 Homework 3 25/11/2016 11:58:30 Word Document 428.75 KB

9-1 OCR Gateway Combined Science A
Topic B1: Cell Level Systems
B1: Homework 3
Mark
Grade
1. Aaron wants to grow some tomato plants.
a) What are the three factors which he could change to make the plants grow faster? (3)
1_____________________________________________________________________________
2_____________________________________________________________________________
3_____________________________________________________________________________
b) Aaron decides to grow his tomatoes in a glasshouse. Explain why he did this. (1)
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
2. A scientist investigated glucose production in swede plants. He looks at five processes, A to E, that
are involved in sugar production. He finds out how energy is lost in each process.
9-1 OCR Gateway Combined Science A
Topic B1: Cell Level Systems
Which process, A,B,C,D, or E produces oxygen gas? (1)
_____________________________________________________________________________________
3. Carbon dioxide and water are needed for photosynthesis.
(a) Finish the balanced symbol equation for photosynthesis. (1)
6CO2 + 6H2O  __________________________ + ____________________________________
(b) In 1649, scientists though that plants grew by only taking in solid material from the soil. A scientist
called van Helmont did an experiment to test this idea. He grew a tree in a large pot of soil. He
measured the mass of the soil and the tree before the experiment. He measured them again, five
years later.
Please turn over
Explain how van Helmont’s experiment proved the scientists wrong. (2)
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
4. Green plants contain chlorophyll. The molecular formula of chlorophyll is C55H72O5N4Mg. Plants get
the magnesium (Mg) they need in form of compounds, such as magnesium sulphate, through their
roots.
(a) How do plants get the carbon (C) they need to make chlorophyll? (1)
_____________________________________________________________________________________
(b) How do plants get the hydrogen (H) they need to make chlorophyll? (1)
_____________________________________________________________________________________
(c) How do plants get the oxygen (O) they need to make chlorophyll? (1)
_____________________________________________________________________________________