Science Unit- Internal and External Structures of Plants

🌱 Lima Bean Plant Experiment 

🌿 What Is a Plant Structure?

A structure is a part of a plant that has a specific function.

• Internal structures are parts of a plant that are found inside the plant.

• External structures are parts of a plant that are found outside the plant.

🌱 The Seed

A lima bean is a seed.

A Lima Bean Seed

Seed coat:
The seed coat is the outer layer of the seed. It protects the inside of the seed.

Think About It:
Why does the lima bean get bigger after we add water?

Possible answer: The seed absorbs water, which causes it to swell and begin the process of germination.

🌱 External Structures of a Plant

Roots

Roots usually grow downward into the soil.

The main jobs of roots are to:

1. Absorb water and minerals from the soil.

2. Anchor the plant in place.

Stem

The stem helps support the plant.

It also transports water and nutrients from the roots to other parts of the plant.

The stem helps move water and nutrients throughout the plant.

As our lima bean grows, we will observe the stem getting taller.

Leaves 🍃

Leaves are usually the green parts of a plant.

Leaves help plants make their own food through a process called photosynthesis.

During photosynthesis, plants use:

• Sunlight

• Water

• Carbon dioxide

Flower 🌸

Flowers are the structures that help many plants reproduce.

Flowers can produce seeds that can grow into new plants.

🔬 Internal Structures of a Plant

Some important plant structures are found inside the plant.

Xylem

Xylem is a type of tissue inside the stem that carries water and minerals from the roots toward the leaves.

Roots → Stem → Leaves

Phloem

Phloem is a type of tissue that transports food/sugars made by the leaves to other parts of the plant.

Leaves → Other parts of the plant

☀️ How Plant Structures Work Together

Each part of a plant has an important job, but the structures must work together for the plant to survive.

Roots absorb water → Stem transports water → Leaves use water and sunlight to make food.

The food made by the leaves can then be transported to other parts of the plant.

🌱 Our Lima Bean Experiment

During our experiment, we will watch the lima bean go through different stages of growth.

We may observe:

☑ The seed absorbing water
☑ The seed coat opening
☑ The root growing
☑ The stem growing upward
☑ Leaves developing
☑ The plant growing taller

🔎 Scientist Question

What do you predict will happen to our lima bean during the first week?

Answers will vary.

🌱 Why Are We Doing This Experiment?

The lima bean experiment will allow us to observe plant structures and observe how they function/work.

Vocabulary Answer Key

Seed- A structure that contains a young plant and the materials it needs to begin growing.

Seed coat- The outer covering that protects the seed.

Root- A structure that absorbs water/minerals and anchors the plant.

Stem- A structure that supports the plant and transports water and nutrients.

Leaf- A structure that makes food through photosynthesis.

Xylem- Tissue that transports water and minerals from the roots upward.

Phloem- Tissue that transports sugars/food made by the leaves to other parts of the plant.

Photosynthesis- The process plants use to make food using sunlight, water, and carbon dioxide.