A leaf has carbon dioxide and water but is kept in a dark box. What missing input prevents the chloroplasts from making normal amounts of glucose?

A bean plant in bright light has dry roots and wilts; its leaves stop making normal sugar. What photosynthesis input is missing?

Air moves through tiny openings in a leaf before sugar is made. What gas must enter the leaf for photosynthesis?

Pondweed under a lamp releases bubbles while it makes sugar. What gas is building up in the bubbles?

In a leaf cell, chloroplasts use light, water, and carbon dioxide. What food molecule is produced?

A sealed leaf bag receives light and contains water vapor and carbon dioxide. What product gas would collect as photosynthesis continues?

Water absorbed by roots must reach the leaf cells that do photosynthesis. Which plant tissue carries the water up the stem?

A plant is lit all day, but a chemical removes carbon dioxide from its chamber. What missing input stops normal sugar production?

A model leaf shows matter going in and out during photosynthesis. Which word equation matches the model?

On a sunny day, the stomata on a leaf are wide open. What trade-off do open stomata create for the plant?

A radish seedling gains 6 g of dry mass in a closed pot, while dry soil mass changes by 0.1 g. Where did most new dry matter come from?

A tree grows a thick trunk over years, but the mineral content of the soil changes only a little. What supplied most of the trunk's carbon atoms?

Tomato plants grow in nutrient solution without soil and gain dry mass. What evidence-based source supplies most of the carbon in their sugars?

A carbon atom in a glucose molecule inside a leaf can be traced backward. Just before photosynthesis used it, where was that carbon atom most likely?

A student says sunlight becomes the mass of a sunflower. What correction best explains the plant's new dry mass?

After watering only, a potted plant gains 500 g of dry mass and the dry soil loses 20 g. What claim does the evidence support?

Plant cell walls are made of a tough material built from long chains of glucose. What is this material?

A fertilizer label lists minerals needed in tiny amounts. Why do minerals not explain most dry mass gained by a plant?

Scientists add carbon dioxide with marked carbon atoms to air around a plant. Later, the marked carbon appears in starch. What does this show?

A closed terrarium plant grows new leaves while liquid water and air are recycled inside. What matter source adds carbon to those new leaves?

When chlorophyll in chloroplasts absorbs sunlight, the cell later contains more glucose. What energy change best explains this result?

A leaf cell without working chloroplasts gets light and carbon dioxide but makes little glucose. What chloroplast role is missing?

Glucose made in a leaf can fuel growth later, even at night. Where is some of the captured light energy stored?

A plant is moved from a sunny windowsill to a dark closet, and starch production drops. What explains the drop?

On a sunny day, a plant cell does both photosynthesis and cellular respiration. Why does the plant give off oxygen overall?

A spinach leaf looks green because chlorophyll absorbs some light and reflects green light. How does absorbed light help photosynthesis?

A lamp warms a leaf, but the leaf also gains starch. What happened to some incoming light energy?

During cellular respiration, plant cells break down glucose made earlier. What does that show about photosynthesis?

A pondweed stem near a bright lamp gives off many bubbles. The same stem far from the lamp gives off few. What conclusion fits the evidence?

A variegated leaf has green and white areas. After light and iodine testing, only green areas show starch. What conclusion is supported?

Three equal plants grow for one week in sealed chambers with the same light, water, and soil. One chamber has its carbon dioxide removed. Why are the other conditions kept the same?

A leaf is partly covered with foil before sunlight. Later, the uncovered part tests positive for starch, but the covered part does not. What was tested?

Two bean plants get equal light and air. One is watered, and the other is not and makes little starch. What input did the investigation test?

A plant in a sealed flask sits under a lamp, and an oxygen sensor reading rises. The flask is then set in ice water under the same lamp, and the reading rises much more slowly. Why?

A classroom sensor shows carbon dioxide levels fall around a lit plant but not around the same plant in darkness. What process explains the fall?

Spinach leaf disks in bicarbonate solution float sooner than disks in plain water under the same light. What conclusion fits?

In a meadow food chain, grass is eaten by a rabbit, and the rabbit is eaten by a fox. How did photosynthesis affect the rabbit?

Algae grow in a pond, tiny animals eat algae, and small fish eat the animals. What role do algae play in energy flow?

Fungi decompose fallen maple leaves. How did photosynthesis earlier affect the matter and energy available to the fungi?

A drought makes prairie grasses photosynthesize less. Mice eat grass seeds, and owls eat the mice. What change is most likely?