Plant Growth and Responses exercise - Free Printable

Let’s go through each question one by one and think carefully about the answers.

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Question 1:
> “To grow and be healthy, every organism needs certain things from the environment.”
> Which TWO things are NOT necessary in order for plants to grow?
> A. fertilizer
> B. water
> C. soil
> D. space

Plants need water (B) — that’s essential.
They also need space (D) — roots and leaves need room to grow.
But do they *need* fertilizer? Not really — many wild plants grow without it. Fertilizer helps them grow better, but it’s not absolutely necessary.
Do they need soil? Actually, no — some plants can grow in water (like hydroponics), or even on rocks or air (air plants). So soil isn’t strictly necessary either.

✔ So the two things that are NOT necessary are:
→ A. fertilizer
→ C. soil

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Question 2:
> Which plant has many stems or trunks?

Think of a bush or shrub — like a rose bush or lavender. They don’t have just one main trunk; they have many branches coming from the ground. That’s called a “shrub”.

✔ Answer: Shrub

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Question 3:
> Which plant has one main woody stem or trunk?

That’s a tree! Trees usually have one thick, woody trunk that supports all the branches.

✔ Answer: Tree

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Question 4:
> Which plant has a climbing stem?

Some plants climb up walls, fences, or other plants using tendrils or twining stems — like ivy, beans, or grapes. These are called “vines” or “climbers”.

✔ Answer: Vine (or Climber)

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Question 5:
> “Growth in plants happen at different times. Some plants grow all year round.”
> Name another time in which plants grow.

If some grow all year, others might only grow during certain seasons — like spring and summer, when it’s warm and sunny. Or maybe after rain. But the most common answer is: during their growing season — which is often spring and summer.

✔ Answer: During spring and summer (or “in the growing season”)

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Question 6:
> “Plants respond to certain things in the environment, these things are called stimuli.”
> List the three stimuli plants respond to.
> (Picture shows: sun, cloud with rain, red arrow pointing down)

The pictures give us clues:
- Sun → light
- Cloud with rain → water
- Red arrow pointing down → gravity

So plants respond to:
A. Light
B. Water
C. Gravity

✔ Answers:
A. Light
B. Water
C. Gravity

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Question 7:
> Study the picture below. State which tropism each area of the plant is responding to.
> (Picture shows a potted plant lying on its side — roots going down, shoot bending up)

Even though the pot is sideways:
- The roots are growing downward → responding to gravity → this is gravitropism (or geotropism)
- The shoot/stem is bending upward → responding to light → this is phototropism

✔ Answers:
Roots → Gravitropism
Shoot → Phototropism

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Question 8:
> Complete the chart. Define the following terms.

We’re defining types of tropisms — how plants grow in response to stimuli.

- Hydrotropism: Growth in response to water. Roots grow toward water.
- Phototropism: Growth in response to light. Stems bend toward light.
- Gravitropism: Growth in response to gravity. Roots grow down, stems grow up.

✔ Definitions:

| Tropism | Definition |
|------------------|-------------------------------------------------|
| Hydrotropism | Growth toward water |
| Phototropism | Growth toward light |
| Gravitropism | Growth in response to gravity (down for roots, up for shoots) |

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Final Answer:

1. A and C
2. Shrub
3. Tree
4. Vine (or Climber)
5. During spring and summer (or growing season)
6. A. Light, B. Water, C. Gravity
7. Roots → Gravitropism; Shoot → Phototropism
8.
- Hydrotropism: Growth toward water
- Phototropism: Growth toward light
- Gravitropism: Growth in response to gravity