Question

photosynthesis and cellular respiration simulation
11 jones, quavon red 3 fri sep 26
you will be examining photosynthesis and cellular respiration in an aquatic plant using dissolved oxygen.
go to https://www.biologysimulations.com/cell - energy - sim link in announcements.
i. background
plants perform both photosynthesis and cellular respiration.

1. how will photosynthesis affect oxygen levels? increase or decrease
2. how will cellular respiration affect oxygen level? increase or decrease

ii. light intensity
experimental question: how does light intensity affect oxygen production?

1. write your hypothesis.

if the light intensity goes down, then

1. set initial simulation with the follow parameters.

number of fish: 0
number of plants: 1
light intensity 100
temperature celsius: 25
light color: white

1. click on run simulation
2. record the starting and ending dissolved oxygen values to 2 decimals.
3. repeat using light intensity 80%, 60%, 40%, 20%, and 0%.
4. calculate and record the do difference.

light % intensity	do start 0 minutes	do end 60 minutes	do difference
80
60
40
20
0

Explanation:

Step1: Recall photosynthesis process

Photosynthesis uses carbon - dioxide and water to produce glucose and oxygen. So it increases oxygen levels.

Step2: Recall cellular respiration process

Cellular respiration uses oxygen to break down glucose and releases carbon - dioxide and water. So it decreases oxygen levels.

Step3: Form hypothesis for light intensity

Since light is required for photosynthesis, if light intensity goes down, the rate of photosynthesis decreases, and less oxygen is produced. So the hypothesis could be: If the light intensity goes down, then the oxygen production will decrease.

Answer:

1. Increase
2. Decrease
3. If the light intensity goes down, then the oxygen production will decrease.