Sec 4 Biology Plant Nutrition & Transport topical questions

State the word equation for photosynthesis, naming the two conditions needed.

Name the leaf tissue with the most chloroplasts and state why its position suits its function.

State what the xylem transports and in which direction, and what the phloem transports.

Define transpiration and name the structures that control it.

Name the pores through which carbon dioxide enters a leaf, and the cells that control them.

Describe three ways in which a root hair cell is adapted for absorbing water and mineral ions.

Describe the complete path of a carbon dioxide molecule from the outside air to a palisade mesophyll chloroplast.

A pondweed gives 18 bubbles per minute with its lamp 20 cm away and 30 bubbles per minute at 10 cm. Calculate the percentage increase in rate and state what the result shows about limiting factors over this range.

Explain why a potted plant wilts after several days without watering, using the ideas of water potential and turgor.

State and explain two things a gardener can do to reduce water loss from freshly transplanted seedlings.

A pondweed’s bubble rate is 6 per minute with the lamp 50 cm away, 12 per minute at 25 cm, and 24 per minute at 12.5 cm. Calculate the percentage increase in rate for each halving of the distance, and describe the relationship between distance and rate over this range.

Describe how guard cells open a stoma, and explain why this matters for photosynthesis and for the plant’s water balance.

Describe how to investigate the effect of light intensity on the rate of photosynthesis of a submerged aquatic plant, naming one variable to measure, two variables to control, and one precaution specific to the heating effect of the lamp.

A freshly weighed leaf of mass 2.5 g is left in a warm, dry room and re-weighed at 2.0 g after one hour. Calculate the percentage loss in mass, and explain the loss in terms of transpiration.

Explain how the structure of xylem suits it for the transpiration stream, and describe the chain of events from a root hair to an open stoma that moves water up a tall tree.

A described graph shows the rate of photosynthesis rising steeply as carbon dioxide concentration increases, then flattening. Name the limiting factor in each region, write the balanced symbol equation for the reaction, and explain why animals depend on this process even though they cannot perform it.

Plan an investigation to show that light is necessary for photosynthesis, using a potted plant and iodine. Outline the preparation, the treatment, the test, and the expected result.

Two identical greenhouse crops are grown side by side: crop A yields 4.0 tonnes per hectare, while crop B — the same variety in the same soil, but grown with extra carbon dioxide pumped into the air — yields 5.2 tonnes per hectare. Calculate the percentage increase in yield and explain it using the idea of limiting factors.