What happens when we cut the plant tubes?

In the previous article, you learnt the important science concepts and answering techniques on plant transport system.

Click here to discover the answering techniques and common misconceptions >>>

https://scienceshifu.com/how-plants-transport-food-and-water/

Before you proceed to read this article, download the free revision notes.

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Now, let’s understand what happens when carrying tubes are removed.

Look at the diagram below.

When the food-carrying tubes are removed at part X, what happens to the stem at part A and B?

Take note of the science concepts

We learnt carrying tubes transport substances. If the carrying tubes are removed, the substances cannot be transported across part X.

Science concept 1

What’s the proper explanation?

Food-carrying tubes are removed at part X. Leaves above and below part X photosynthesise and produce glucose.

Glucose cannot be transported across part X.

The glucose accumulates above and below part X, causing the stem to swell directly above and below part X.

Take note of the proper description of the stem:

Stem swells just above and below part X.

Ok. I got the correct explanation. Will the leaves above part X continue to grow healthily after 1 week?

Yes! The water-carrying tubes are not removed at X. Water can be transported from the roots to the rest of the plants (including the leaves above part X).

Leaves above part X will absorb the water to photosynthesise and make its own food.

Hmmm….. what happens when I remove both food-carrying tubes and water-carrying tubes?

Bingo!

That’s what a curious science student should be.

Let’s see what happens.

Science concept 2

Take note of the proper explanations

Water-carrying tubes and food-carrying tubes are removed at part X.

Water and glucose cannot be transported to the leaves above part X. Leaves above part X cannot absorb water and will eventually wilt and die due to lack of water.

OR

Leaves above X cannot photosynthesise and cannot make glucose. Leaves die due to lack of food.

OR

No food is transported to the leaves and they eventually die due to a lack of food.

We’ve covered the important science concepts.

Now, its time to practise the answering techniques.

There are 2 main ways how this topic is tested:

1) What happens when you put the plant into a container filled with coloured water

2) What happens when we remove certain sections of the stem.

Now, you can be a fortune teller and predict the future

Well.. sort of. You need to apply the science concepts. 🙂

Like a fortune-teller predicting the future, you need to describe what happens next.

Example 1

Mary had a balsam plant. She ensures the stem is exposed. She then placed the balsam plant into a beaker containing red-coloured water as shown below.

Example 1 (a) What will happen to the leaves of the plant after 2 hours?

Take note: this question is asking you to predict the future! Use the science concept of water-carrying tubes to answer this question.

Ready for the answer?

Let’s see some of the wrong answers.

Wrong answer 1

The leaves grow healthier.

Teachers’ comments:

This answer is NAQ (Not answering question). It is obvious this question is asking you about the plant transport system topic.

Clues spotted in the question are “cut away stem” and “red-coloured water” and “What will happen to the leaves”.

Incomplete answer

The leaves turn red.

Your child may have written out the above answer (Some textbooks show this too).

In fact, many of the leaves do not turn completely red. They are tainted red or they turn partially red. Look at this diagram below.

*An experiment we conducted in the weekly physical classes. The leaves are tainted blue after placing the celery plant in a container of blue-coloured water for 2 hours.

Moreover, the timeframe is short. This experiment lasts for 2 hours. Hence, it is hard for the leaves of the plant to become red completely.

This then brings me to the correct answer.

Correct answer:

The leaves turn partially red.

OR

The leaves are tainted red colour.

Example 1 (b) Explain your answer.

Whats the proper way to explain the answer?

Let’s look at the wrong answers.

Wrong answer

Red-colour is carried to the leaves, turning the leaves partially red.

Teachers’ comments:

This is not about the red-coloured food dye. We need to write “red-coloured water”.

Alsp, the student misses out the important keywords: water-carrying tubes.

To explain this concept clearly, follow the answering technique. This needs to have two pointers:

• Describe the plant part
• Apply the function of the plant part.

Apply the answering technique from above (we use the relevant colours):

Answering technique

• Describe the plant part – Water-carrying tubes
• Apply the function of the plant part – transport/ carry the red-coloured water to the leaves

Correct answer

The exposed stem absorbs the red-coloured water. The water-carrying tubes transport/ carry the red-coloured water to the leaves, turning the leaves partially red.

Do you notice this answering technique is derived from the function of the carrying tubes?

Should you need more help with the answering techniques, you can download this free ebook

This ebook contains answering techniques across multiple topics.

Common exam questions included inside for your child to learn and revise.

Click Here To Download

Example 2

Farmer James wants to grow big apples.

He learnt about the science concept on plant transport systems. He decided to apply the science concept by removing an outer portion of the stem at part X (see diagram below).

Farmer James removed part X of the stem as shown below.

Take note of the clues!

Part X – Outer portion of the stem removed. That means only the food-carrying tubes are removed.

Which apple Y or Z grow bigger after 1 month? Explain your answer.

To explain this concept clearly, follow the same answering technique. This needs to have two pointers:

• Describe the plant part
• Apply the function of the plant part.

Apply the answering technique from above (we use the relevant colours):

Answering techniques

• Describe the plant part – Food-carrying tubes removed
• Apply the function of the plant part – cannot transport glucose from the leaves to all parts of the plant.

Correct answer

Apple Z grows bigger than apple Y.

Leaves on the apple tree photosynthesise and produce glucose.

With the food-carrying tubes removed at part X, glucose cannot be transported from the leaves on Z to all parts of the plant.

Instead, leaves at Z transported more glucose to apple Z than the leaves at Y transport the glucose to apple Y.

Note: you are comparing between two apples. You need to use comparative words.

Think you’ve got the proper answering techniques?

Let’s try out this question

Example 3

One day, the farmer asks his playful son, Jeremy, to remove a portion of the stem on another apple tree similar to example 2. He did not follow the instructions (Oh No!) and removes the outer ring of the stem as shown below.

What will happen to the apple fruit one month later? Explain your answer.

(Apply the answering technique and try out on your own first)

To explain this concept clearly, follow the same answering technique. This needs to have two pointers:

• Describe the plant part
• Apply the function of the plant part.

Apply the answering technique from above (we use the relevant colours):

Answering techniques

• Describe the plant part – Food-carrying tubes removed
• Apply the function of the plant part – cannot transport glucose from the leaves to the roots

• Describe the plant part – Roots die due to lack of food
• Apply the function of the plant part – cannot absorb water

• Describe the plant part – Water-carrying tubes
• Apply the function of the plant part – no water is transported

 Correct Answer

The apple fruit will dry up and become smaller.

With the food-carrying tubes removed at part C, no food can be transported to the roots.

The roots die due to a lack of food. There are no roots to absorb water.

No water is transported from the roots to the apple fruit using the water-carrying tubes.

Eventually, the fruit dries up and becomes smaller.

Takeaway from this revision notes

Examiners love to combine multiple concepts. You need to master the proper answering techniques across different topic.

You can see similar answering techniques are used across different questions. That is the mastery of science concepts.

You can download this revision notes so your child can revise them anytime.

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In the weekly classes

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Join our many students who are developing a curious mind while honing their answering techniques.

Click on this link below for the online Zoom classes:

https://gradesolution.com.sg/online-zoom-classes/

Next, click on the “sign up now” button and select the respective class schedules.

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Next, click on the “sign up now” button and select the respective class schedules at the respective branches.

Talk again soon!

Andy Ling