Plant Structures

Lesson Plan - Get It!

Audio:

There are many types of plants on the earth.

Some have specialized tissues for moving water and nutrients, while others stay low to the ground to absorb water and nutrients.

In this lesson, learn about plant structures that help vascular plants function. Vascular plants can grow from the earth's surface because they have xylem and phloem for moving materials throughout the plant.

Plants get most of their required water and nutrients from the surrounding soil. They soak these materials with roots.

Roots extend from the bottom of the plant and can branch in many directions to collect as much water and food as possible.

Roots of trees and large plants go deeper than roots of grasses or mosses.

Some vegetables grow from roots, like carrots and jicama, a starchy root vegetable. Potatoes and yams are called tubers and are specialized structures that grow off roots responsible for storing food for the plant.

Roots have a very special region called the apical meristem. This region is responsible for telling plant cells to divide. When plant cells divide, the plant grows!

Another unique cell found in roots is root hairs. These cells look like small hairs extending off the root tip and can make the root look fuzzy, as shown in the image below.

Each small root hair increases and the plant is responsible for collecting and transporting water and nutrients through the plant.

Roots can extend above ground, but once the plant emerges from the soil, it is generally called a stem. The stem is the central part of the plant that includes both the trunk and branches.

Not all plants have a trunk, but large trees can have very thick trunks.

Branches are the parts of the plant that extend out from the trunk and contain leaves.

Leaves are responsible for carrying out photosynthesis for the plant. Leaves can produce energy for the plant because of the vascular tissues xylem and phloem that carry water and nutrients up from the soil.

New branches originate from nodes on the stem that eventually grow into axillary buds or structures where new branches can develop.

Plants have interesting structures that allow them to grow tall and wide.

While not all plants grow as large as a redwood tree, vascular plants share common characteristics, like roots, stems, and leaves. Roots and stems are critical for plant growth.

• How might the structure of these plant parts influence their function in the plant?
• What would happen to a plant if it lost one of these structures?

When you are ready, move on to the Got It? section, where you will review the relationship between structure and function.