Plant Structures and Their Functions | Edexcel GCSE Combined Science Biology, Foundation tier (1SC0)

Plant Structures and Their Functions

91 questions
6 subtopics
Paper 2
Paper 2

Plant Structures and Their Functions is examined in Paper 2, Biology 2.

It covers photosynthesis and its limiting factors, investigating light intensity and the rate of photosynthesis, root hair cells, xylem and phloem, transpiration and translocation, and the factors affecting transpiration and the potometer.

Sample questions from Plant Structures and Their Functions

Answer each one closed book first, then open the answer.

Photosynthesis as an endothermic reaction

Explain why animals depend on photosynthetic organisms for their food.

Show the answer
Animals cannot make their own food, so they must obtain it by eating producers or by eating other animals that ate producers.
Photosynthesis as an endothermic reaction

Name the pigment that absorbs light for photosynthesis and state where it is found.

Show the answer
Chlorophyll, which is held inside the chloroplasts of plant and algal cells.
Limiting factors in photosynthesis

Explain why the rate of photosynthesis stops rising when light intensity is increased beyond a certain point.

Show the answer
Light is no longer the factor in shortest supply, so something else such as carbon dioxide concentration or temperature is holding the rate back.
Limiting factors in photosynthesis

Describe the effect of increasing carbon dioxide concentration on the rate of photosynthesis.

Show the answer
The rate increases as carbon dioxide rises, then levels off once a different factor becomes the one in shortest supply.
Light intensity and the rate of photosynthesis

Explain why the pondweed is left for a few minutes after the lamp is moved before any bubbles are counted.

Show the answer
It gives the plant time to settle at the new light intensity, so the reading measures the rate at that intensity.
Light intensity and the rate of photosynthesis

What is the difference between a hypothesis and a prediction?

Show the answer
A hypothesis explains why something happens, while a prediction states what the result of an experiment will be if the hypothesis is correct.
Root hair cells, xylem and phloem

Explain how having a thin surface layer helps a root hair cell absorb substances.

Show the answer
The short distance to cross means water and mineral ions enter the cell quickly.
Root hair cells, xylem and phloem

Explain the advantage of xylem vessels having no cytoplasm or organelles inside them.

Show the answer
The empty lumen lets water flow through with very little resistance.

The 6 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Photosynthesis as an endothermic reaction	Producers, biomass and why animals depend on photosynthetic organisms, the word and balanced symbol equations for photosynthesis, why it is endothermic, chlorophyll in chloroplasts, where the raw materials come from, and how a plant uses the glucose and oxygen it makes.	13
Limiting factors in photosynthesis	What a limiting factor is, how light intensity, temperature and carbon dioxide concentration each affect the rate of photosynthesis, why the rate levels off in bright light and falls above about 45 °C, what limits a warm, brightly lit greenhouse, and what a flat section of a rate graph shows.	8
Light intensity and the rate of photosynthesis	Measuring the rate of photosynthesis in pondweed, the independent and control variables in the lamp-distance investigation, using a beaker of water, sodium hydrogencarbonate, settling time and a darkened room, improving on counting bubbles, the expected results, and hypotheses, predictions, conclusions and whether data support them.	17
Root hair cells, xylem and phloem	How root hair cells absorb water by osmosis and mineral ions by active transport, why salty water makes a plant wilt, how dead, lignified xylem vessels carry water, and how phloem sieve tubes and companion cells use energy to move sucrose up and down the plant.	15
Transpiration and translocation	Transpiration and the path of water from soil to air, how evaporation pulls water up the xylem, stomata and how guard cells open and close them, wilting, and the translocation of sucrose in the phloem from the leaves to growing regions and storage organs using energy from respiration.	14
Factors affecting the rate of transpiration	How light, wind, temperature and humidity affect water uptake, setting up and using a potometer, why uptake only estimates transpiration, calculating rates per minute, per hour, by volume and per unit of leaf area, and plotting graphs, lines of best fit, gradients, intercepts and y = mx + c.	24

Plant Structures and Their Functions is 91 of the 904 questions in the guide.Get the guide, £7

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.