Question

Mr. Miller's biology class is studying cellular respiration. To model cellular respiration, they set up an experiment containing four flasks. Each flask is the same size and are stoppered and placed under a floodlight. Each flask also contains 200 mL of H20 and 2 mL of bromothymol blue. Bromothymol blue is a chemical indicator solution that changes color from blue to yellow in the presence of CO2. The students then place a plant and/or fish into each flask (except for Flask #4 which is the control group) according to the table above. Which flask(s) will turn yellow and why?
A) Flask 1 & 3 because these flasks contain plants that undergo photosynthesis.
B) Flask 3 (only) because this is the only flask in which photosynthesis and cellular respiration are both taking place.
C) Flask 1 & 2 because there is only one process taking place in each of these flasks so the products do not get used up.
D) Flask 2 (only) because the fish produce CO2 as products of cellular respiration and do not undergo photosynthesis therefore not consuming CO2.

Answer 1

Answer:

Option-D

Explanation:

Fish respires and produces CO2, and te released CO2 is not used up. So in falsk 2, colour changes to yellow.

Answer 2

Answer:

Option D) Flask 2 (only) because the fish produce CO₂ as products of cellular respiration and do not undergo photosynthesis therefore not consuming CO₂.

Explanation:

• Cellular respiration refers to the process by which food substances such as glucose, are broken down into $CO_{2}$ and $H_{2}O$ as the by-products to produce energy in the form of ATP.

• This process takes place both in plants and animals. In plants $CO_{2}$ produced from cellular respiration is utilized in photosynthesis.

• As given, Bromothymol blue is a chemical indicator solution that changes colour from blue to yellow in the presence of $CO_{2}$.

• Since the fish produced $CO_{2}$ as the by-product of respiration is not consumed for photosynthesis by plants, the Bromothymol blue turned yellow in flask 2.

Hence option D) (only) because the fish produce $CO_{2}$ as a by-product of cellular respiration and do not undergo photosynthesis therefore not consuming $CO_{2}$ .