Do now!
Can you read
pages 26 to 35 of
your book?
9d – Plants as food
Remember food webs/chains?
ALL food chains/webs start with
plants (“producers”)
We eat many different parts of
plants
Flowers
Leaves
Fruits
Stem
Storage organs
Roots
Seeds
Energy
We gain energy by eating the starch in
plants
Helping crops to grow
• When plants die, the mineral salts (often
called nutrients) are returned to the soil by
decomposition.
Helping crops to grow
• When crops are harvested, this cannot
happen, so the nutrient level of the soil
drops.
Helping crops to grow
Fertilisers must be used to replace these
nutrients
Manure is a natural
fertiliser.
Decomposers in
the soil decompose
the manure to put
nutrients back in
the soil.
Greenhouses
Also known as
a glasshouse
Greenhouses
•
•
•
•
Plants grow better
(through photosynthesis) with
Warmth
Water
Light
CO2
Greenhouses
•
•
•
•
Plants grow better
(through photosynthesis) with
We photosynthesize best
Warmth
at 30°. Above 40° some
of the enzymes used for
Water
photosynthesis are
damaged
Light
CO2
Sometimes pumped into
greenhouses to increase growth