Lab # 11
Lab Date: 10/18/22
Lab Title: Homeostasis [ Plant Hormone- Ethylene]
Lab Skill: PD
Problem Statement:
A vendor observes that when apples are placed in the same fruit basket with green
bananas. The bananas ripe faster than when they are placed in a fruit basket
containing green bananas only.
Hypothesis : The ripening of an unripe green banana will be affected by storing it with a ripe
apple.
Aim: To investigate the effects of the ethylene hormone caused by apples on green bananas
while also using an iodine complex to test for the presence of starch.
Apparatus/ Materials: 4 ripe apples, 4 green bananas, resealable plastic bags, iodine
solution, distilled water
Method:
1. Label 2 plastic bags A & B.
2. Place one ripe apple and unripe green bananas in a plastic bag labelled A.
3. Place one unripe green banana in a plastic bag Labelled B and seal both bags.
4. Place the bags together and record initial observations of the fruits.
5. Observe and record any changes seen in the appearance of the fruits for the next 3- 5
days.
6. Test the fruits for starch by staining them with the iodine complex.
Expected Results:
The bag with the green bananas and ripe apples will ripen faster than the bag with green
bananas only. At the end of the experiment in testing for starch the bag with the green
bananas only will have more starch present while the bag with the ripe apples and green
bananas will show a negative test result indicating that sugar is more prominent.
Variables:
Independent: Bag with ripe apples and green bananas
Dependent : Colour, texture, scent, amount of starch present
Controlled: The bag with green bananas only
Limitations : The amount of ethene gas that the ripe apples will produce
Sources of Error: Not ensuring that the plastic bags are sealed tightly and not having the
appearance of holes
Precaution:
●
Ensure that the green bananas were cut from the same stem.
● Ensure that observations are recorded at a consistent time.