Question

1. the tropical rainforests are sometimes called the \lungs of the earth\ because of the abundance of plant species. which two atmospheric gases are balanced by tropical rainforests?

a nitrogen
b oxygen
c carbon dioxide
d carbon monoxide
e water vapor

1. which three compounds are produced during the light dependent reactions of photosynthesis?

a oxygen
b atp
c glucose
d nadph
e water
f carbon dioxide

1. the diagram below represents the gas exchange relationship between photosynthesis and cellular respiration.

diagram of a plant, a cow, and two arrows labeled 1 and 2
part a
what does the arrow labeled 1 represent?
a water
b glucose
c oxygen
d carbon dioxide
part b
what does the arrow labeled 2 represent?
a water
b glucose
c oxygen
d carbon dioxide

1. a student constructs a closed aquatic ecosystem to study the effects of light intensity on the rates of photosynthesis and oxygen concentrations. she places several elodea (aquatic plants) along with water and nutrients in a sealed 1 liter glass bottle. she varies light intensity by placing a light source at various distances from the bottle. she then records the number of oxygen bubbles produced for a 30 minute interval, and she also monitors the oxygen concentration in the air of the closed ecosystem by using an oxygen sensor. her data shows that oxygen formation increases as light intensity increases, but the oxygen concentration as measured by the sensor does not continually rise. she concludes that she must have a leak in her closed ecosystem. which of the following is the best alternative explanation for her oxygen concentration readings?

a the plants are also using oxygen while undergoing cellular respiration.
b excess oxygen is causing plant cell death.
c some of the oxygen is combining with the air to form water.
d microscopic bacteria in the water are also performing photosynthesis.

Explanation:

Question 25

Tropical rainforests perform photosynthesis (absorb CO₂, release O₂) and respiration (absorb O₂, release CO₂), balancing oxygen (O₂) and carbon dioxide (CO₂) in the atmosphere. Nitrogen, carbon monoxide, and water vapor are not the main gases balanced here.

Light - dependent reactions of photosynthesis split water, produce oxygen (O₂), and generate energy - carrying molecules ATP and NADPH. Glucose is made in light - independent reactions, water is a reactant, and CO₂ is used in light - independent reactions. So the three compounds produced are oxygen, ATP, and NADPH.

In the gas exchange between photosynthesis and cellular respiration, the cow (animal) undergoes cellular respiration, which produces carbon dioxide (CO₂) and releases it. This CO₂ is taken up by plants for photosynthesis. So the arrow labeled 1 (from cow to plant) represents carbon dioxide.

Answer:

B. oxygen, C. carbon dioxide

Question 27