Photosynthesis

When light is absorbed by chlorophyll molecules in the first phase of photosynthesis, they lose electrons, what happens to the reactant water molecule. What does it break down into?

• water splits into 2H and an O and oxygen is created

• it oxidizes into glucose

• it fixes carbon

• it breaks down ATP

The reactions of the Calvin cycle (light-independent cycle) are not directly dependent on light. Which of the following statements explains why not?

• Carbon dioxide is not available at night.

• The Calvin cycle(light-independent cycle) depends on products of light reactions.

• It is too cold at night for reactions to take place.

• Most plants do not make the 4-carbon compounds that would be needed for the Calvin cycle to occur at night.

Chlorophyll is the primary pigment in plant chloroplasts. It absorbs all wavelengths of light EXCEPT __________.

• red

• yellow

• green

• blue

Which is an autotroph?

• earthworm

• mushroom

• wolf

• a flower

Which part of the chloroplast absorbs light?

• mitochondria

• pigments

• stomata

• thylakoids

Which reaction takes place in the thylakoid discs of the chloroplast?

• carbon fixation

• light-independent reaction

• light-dependent reaction

• Calvin cycle

Infer why chloroplasts are found mostly in the leaves of plants.

• The large surface area of leaves allows for contact with oxygen.

• Chlorophyll interferes with the xylem and phloem in the stems and trunks of plants.

• The waxy coating on the surface of leaves helps prevent evaporation.

• The large surface area of leaves allows for maximum light absorption.

Which is a product of photosynthesis?

• ATP

• glucose

• water

• carbon dioxide

Which is formed during the Calvin Cycle (light-independent) phase of photosynthesis?

• ATP

• NADPH

• glucose molecules

• pigment molecules

What change can be measured to collect data about the rate of photosynthesis in algae submerged in water when it is exposed to light?

• the temperature of the water surrounding the algae

• the number of ribosomes in the green algae cells

• the color of algae

• the number of gas bubbles given off by the algae