Unit 1 - Photosynthesis: Plants & Food Flashcards
WHAT is photosynthesis? OR
EXPLAIN what happens during photosynthesis.
The process in which plants make their OWN FOOD from CARBON DIOXIDE (from the air) and WATER (from the soil), using LIGHT ENERGY (from the sun).
During this process, the plant releases OXYGEN.
The food they make is GLUCOSE SUGAR.
WHAT is glucose?
It’s a TYPE OF SUGAR used as an ENERGY SOURCE for many living organisms.
WHERE does photosynthesis take place?
Mainly in the LEAVES which are THIN and FLAT, so the plant can easily absorb the sunlight.
WHY and HOW do plants store glucose?
Plants make more glucose than they can use straight away, so it is STORED in the form of STARCH.
They store it in their LEAVES, STEMS, ROOTS, FLOWERS, FRUIT and SEEDS.
EXAMPLES: Carrots - starch stored in ROOTS Potatoes - starch stored in STEMS Bananas - starch stored in FRUIT Aloes - starch stored in LEAVES
What is starch?
Glucose sugar that is CHANGED and STORED in plants.
What is a hypothesis?
A STATEMENT that is a possible ANSWER to a question.
Write a hypothesis like this:
IF ………. [I do this], then …………. [this] will happen.
What can we use to test for starch?
Iodine.
What is the starch test?
Iodine is used to test for starch.
If start is present, iodine turns from BROWN to BLUE-BLACK.
WHY does the Delicious Monster have holes in its leaves?
- STRONG WINDS pass through the holes, so the leaves don’t get damaged.
- SUNLIGHT passes through the holes, so the big leaves at the top don’t block the sunlight for the leaves below.
WHY do plants need fertiliser?
Plants need some nutrients that they CAN’T MAKE THEMSELVES.
Eg. nitrogen, potassium and phosphorus.
By adding fertiliser/plant food to the soil, nutrients dissolve in water and plants absorb them through their roots.
What nutrients can’t plants make themselves?
Nitrogen, potassium and phosphorus.
What are nutrients?
Substances in food that are important for growth or good health.
