The Anatomy of a Plant

Do plants have anatomy?

As you learned early in the course, all living things must be able to maintain homeostasis (internal stable temperature and surroundings). How do plants maintain homeostasis? In order for you to learn the physiology of plants, you must first understand plant anatomy.

What Makes it a Plant?

What makes plants so unique from other organisms? In order to answer this question, we need to study plants at the cellular level first.

This is a picture of a plant cell. What makes it different from animal cells?

Plant Cell vs Anima Cell, Labels listed in document below

See description of diagram

So What Makes them Different?

While both plant and animal cells are eukaryotes, there are a few differences:

A plant cell has chloroplast to make food.
Plants have a cell wall composed of cellulose.
Plants have a large vacuole to store water and minerals, as well as to help keep the plant upright.

Plant Tissue

Remember that many cells that work together make up tissue. Let’s take a look at the different types of plant tissue.

Click through the Notes below to study each type of tissue.

Plant Organs: Leaves, Roots, & Stems

Why are Leaves so Important?

PHOTOSYNTHESIS!
Leaves carry out photosynthesis. Their position and shape allow them to absorb the maximum amount of sunlight possible.

Photosynthesis Animation, see description below

See description of diagram

Circulation and Gas Exchange!

What processes are needed for photosynthesis to occur?

Capillary action moves water up to the top of very tall trees by capillary action, the adhesion/cohesion of water, transpiration pull, and root pressure.
A tree behaves like a big straw; as water evaporates from the leaves at the top (transpiration) water moves in at the roots to replace it.
Cohesion (what holds the water together) is a consequence of the high surface tension of water due to hydrogen bonding.

Structure of Leaves

Roll your mouse over each of the hot spots to learn more about the internal parts of a leaf.

So, the stomata and the guard cells work together to regulate gas exchange.

Stomata open during the day to allow photosynthesis to occur and close at night. The guard cells will swell or shrink, which results in the opening and closing of the stomata.

Plants keep their stomata open just enough to allow photosynthesis to take place, but not so much that they lose an excessive amount of water; stomata are usually open during the day so that photosynthesis can occur and closed at night.

CO2 goes into open stomata, H2O is released when stomata closes

Challenge and Before You Go

Practice Time! Use the knowledge you learned from the lesson to complete the practice activities below.

Before You Go - You Need To Know

The following key points are from the explore section of the lesson. You must know the following information before moving to the next lesson. This is just a summary of the key points.

Four types of tissue exist in plants:

Dermal tissue
Vascular tissue
Ground tissue
Meristematic tissue

2. Just as in animals, tissues combine in plants to create organs that each serve important functions in plants.
Leaves carry out photosynthesis. Their position and shape allow them to absorb the maximum amount of sunlight possible.

IMAGES CREATED BY GAVS (FREEPIK)