Educational worksheet on plant tropisms, detailing phototropism, geotropism, and hydrotropism with illustrated examples and definitions.

Let's solve and complete the "Plant Tropisms: ISN Guided Notes" worksheet step by step. I'll fill in all the blanks with correct scientific terms and explain each part.

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🔹 Definition of Tropism

> Tropism – Plant movement toward or away from a
> ✔ stimulus

👉 *Explanation:* A tropism is a directional growth response in plants to an external stimulus (like light, gravity, or water).

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🔹 Positive vs. Negative Tropism

- + Positive Tropism = To turn
✔ toward a stimulus.
*(Example: Stems growing toward light)*

- – Negative Tropism = To turn
✔ away from a stimulus.
*(Example: Roots growing away from light)*

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🔹 3 Types of Tropisms

#### 1. Phototropism
> The movement of a plant in response to light.

- Movement TOWARD the stimulus (light) = Positive Phototropism
➤ Example: Stems grow toward light.

- Movement AWAY from the stimulus (light) = Negative Phototropism
➤ Example: Roots grow away from light.

✔ So, fill in:
- First blank: light

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#### 2. Geotropism
> The movement of a plant toward or away from the gravity.

- Stems and Leaves = Negative Geotropism
➤ They grow upward, against gravity.

- Roots = Positive Geotropism
➤ They grow downward, toward gravity.

✔ Fill in:
- Blank: gravity
- Stems and Leaves: Negative Geotropism
- Roots: Positive Geotropism

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#### 3. Hydrotropism
> The movement of a plant in response to water.

- Roots grow TOWARD the stimulus (water) = Positive Hydrotropism

✔ Fill in:
- Blank: water
- Roots grow toward water → Positive Hydrotropism

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🔹 Lesson Summary

Now, let’s complete the summary section:

1. Tropisms occur when plants respond to
✔ external stimuli (or environmental factors)

2. Tropisms are
✔ growth responses caused by a change in a plant's growth pattern.

3. Tropisms can be
✔ positive or negative

4. If the plant moves
✔ toward the stimulus, the tropism is positive.

5. If the plant moves away from the stimulus, the tropism is
✔ negative

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✔ Final Completed Worksheet Answers:

#### Definitions:
- Tropism – Plant movement toward or away from a stimulus.
- + Positive Tropism = To turn toward a stimulus.
- – Negative Tropism = To turn away from a stimulus.

#### 3 Types:
1. Phototropism: Response to light
- Toward light = Positive phototropism (stems)
- Away from light = Negative phototropism (roots)

2. Geotropism: Response to gravity
- Stems/leaves = Negative geotropism
- Roots = Positive geotropism

3. Hydrotropism: Response to water
- Roots grow toward water = Positive hydrotropism

#### Lesson Summary:
- Tropisms occur when plants respond to external stimuli.
- Tropisms are growth responses caused by a change in a plant's growth pattern.
- Tropisms can be positive or negative.
- If the plant moves toward the stimulus, the tropism is positive.
- If the plant moves away from the stimulus, the tropism is negative.

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🌱 Why Do Plants Have Tropisms?

Plants use tropisms to optimize survival:
- Phototropism helps leaves get maximum sunlight for photosynthesis.
- Geotropism ensures roots anchor into soil and stems reach air.
- Hydrotropism allows roots to seek water sources.

These responses are controlled by plant hormones like auxins, which redistribute in response to stimuli, causing differential cell growth.

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