The Hierarchy of Structure in Plants

The Hierarchy of Structure in Plants

Organs

Each organ system is made up of highly specialized organs and other structures

These organs and structures work together to perform the overall function of the system

There are 4 major organs found in plants:

• leaves
• stems
• roots
• flowers

Organ Systems

Leaves

• divided into 3 parts
• middle leaf
• upper leaf
• lower leaf
• most important job:
• to provide enough surface area for photosynthesis to take place

All plants accomplish the same basic functions regardless of their appearance, behavior, or where they live

They all obtain water and nutrients, and eliminate waste, grow and repair damage, and reproduce

These are all functions of the organ systems

Stem

• 2 major functions
• physical support
• transportation of water, nutrients & sugar

Roots

• anchor the plant to the ground
• root hairs allow the plant to take up water and minerals from the soil
• act as the plants storage area

Shoot System

Tissues

• made up of the rest of the plant that is above ground
• is responsible for
• supporting the plant
• preforming photosynthesis
• transporting water, minerals & sugar

Root System

• made up off all the roots that lie below the surface of the ground
• is responsible for taking in water and minerals from the soil
• transports water and nutrients to the shoot system

There are three major types of tissue in plants

• Dermal tissue
• Ground tissue
• Vascular tissue

Flower

• responsible for plant reproduction

Ground Tissue

• is responsible for storing the carbohydrates produced by the plant
• makes up the majority of a young plant and lies between the vascular and dermal tissues.

Vascular Tissue

• xylem
• which conducts water and minerals from the roots upward and throughout the plant
• phloem
• which transports dissolved nutrients in all directions within the plant.

Dermal Tissue

• functions to protect the plant from injury and water loss
• covers the outside of the plant, except in woody shrubs and trees, which have bark

Hierarchy

All plants are made up of cells that are organized in a way that allows them to perform all of life's functions

Within every plant there are levels of organization that form a hierarchy. The hierarchy is organized with

• most complex items at the top
• least complex items at the bottom

Levels of Organization

Simplest to complex

• Cell - the smallest structural and functional unit of an organism
• Tissue - a collection of similar cells that perform a particular but limited, function
• Organ - a structure composed of different tissues working together for perform a complex body function
• Organ system - a system of one or more organs and structures that work together to perform a major vital body function such as digestion or respiration
• Organism - the product of many different organ systems working together

Overview

Multicellular organisms, such as plants, are made up of many different specialized types of cells

• each cell is specialized to perform a specific function
• specialized cells depend on each other for survival
• A single root hair cell, parenchyma cell, or sclerenchyma cell would die quickly if separated from its surrounding cells
• These cells live and work together as part of a much larger group of cells that make up the body of a plant
• The complexity of plant bodies varies. Some plants have a simple body structure, while others are more complex

Single-celled organisms, such as bacteria and blue-green algae, function independently

• do not depend directly on other cells