Plant transport system is a topic with only 2 essential concepts.
1. There are food-carrying and water-carrying tubes in the stem that transport food and water to all parts of the plant.
2. The transport of water is one way, from the roots to the leaves (All parts of the plant). The transport of food is also one way, from the green parts to all parts of the plant.
However, the questions can be tricky and requires specific key words e.g. transport.
Let’s take a look at this MCQ question from Methodist Girls’ School P5 2019 SA2.
The diagram below shows how substances are transported in a plant.
Which of the following correctly represent the substances P and Q?
The answer is 4.
This question is very common in SA2 exams and it requires a firm foundation of concepts in this topic. Mineral salts can only be dissolved in water and often absorbed together with water by the roots. Food is usually made by the leaves and transported to other parts of the plant.
Students must not be careless in this question and use the legend
carefully to arrive to the answer.
Another possible representation of the options is food and nutrients.
Water and mineral salts always go hand in hand. Food and nutrients always go hand in hand.
Another question here! Rulang Primary, P5 2018 SA2
Chantel set up an experiment by removing either food-carrying tubes or water-carrying tubes or both tubes of two similar plants, X and Y. The plants were then placed in beakers containing the same amount of red-coloured water as shown in the diagram below.
The observations of the plants were recorded in the table below.
(a) Explain why the stem above A of Plant X swelled. 
This is a typical P5 question for Plant Transport system and there is a fixed way to answer such questions.
- Identify the missing tube of the plant transport system
- Explain how the substances (either food or water) are unable to be transported to other parts of the plant
- State the effect of the missing substances on other parts of the plant.
Let’s apply to the above question!
Let’s use the same method on Part B of this question.
Chantel observed that Plant Y dried up and died on the 5th day. Explain how this happened.
Here’s additional information you must know about this topic.
What are the keywords to use for plant transport system?
- Transport/ carried [DO NOT use ‘go up/ go down’, travel, flow]
- Food-carrying tubes
- Water-carrying tubes
- Excess Food / Starch
- Roots absorb / take in water
- Food made by the leaves
- Stored/ Accumulated
- Cut Stem
For the complete list of keywords , you can always check out our P5 Keyword Passport!