Plant anatomy and physiology

Plant Anatomy and Physiology

Basic Structures of a Plant

• A plant generally comprises three specific parts: the root system, the stem or trunk, and the leaves.
• The root system anchors the plant, absorbs water and minerals and often stores food.
• The stem or trunk provides support, conducts water and nutrients between the roots and leaves, and stores food.
• Leaves are the plant’s main photosynthetic organs where energy from sunlight is used to convert carbon dioxide from the air into oxygen and glucose.

The Function of Plant Roots

• Roots perform multiple functions for plants. The most obvious ones are providing stability and absorbing water and nutrients from the soil.
• Additionally, some roots act as storage organs, storing starches and sugars that the plant can use during periods of limited resources.
• Root hairs significantly increase the root’s surface area, enhancing water absorption.

Plant Stems

• The stem of a plant has several key jobs. It supports the plant body and acts as a conduit for water, nutrients, and sugars between the roots and leaves.
• In some plants, stems can store food or water, like the thick trunk of a baobab tree.

Leaves and Photosynthesis

• Leaves, generally green in colour, are the powerhouse of the plant, where photosynthesis occurs.
• Photosynthesis is the process by which light energy is transformed into chemical energy, resulting in the formation of sugars which fuels all plant activities.
• Leaves are also important for gas exchange - taking in carbon dioxide necessary for photosynthesis, and releasing oxygen, a by-product of the process.

Plant Growth and Differentiation

• Plant growth involves cell division (mitosis), cell enlargement, and cell differentiation.
• The areas from where a plant grows are called meristems - these are tissues containing undifferentiated cells ready to develop into various plant parts.
• Meristems located at the tips of roots and shoots (apical meristems) enable the plant to increase in length, a type of growth known as primary growth.

Remember, understanding plant anatomy and physiology is pivotal to appreciating how plants interact with other organisms and their environment. This knowledge also provides insight into the vital role plants play in Earth’s ecological balance.