Plant anatomy and physiology

Plant anatomy and physiology

Plant Cells and Tissues

• Plants are made up of plant cells that include specialised parts such as cell wall, chloroplasts, and a central vacuole.
• Plant tissues are organised into vascular tissues (xylem and phloem), ground tissues (parenchyma, collenchyma, and sclerenchyma), and dermal tissues (epidermis and periderm).

Roots, Stems and Leaves

• Roots absorb water and minerals, anchor the plant, store food, and produce hormones.
• Stems support the plant, transport materials, store food, and produce leaves and buds.
• Leaves are the main site for photosynthesis and gas exchange in plants.

Vascular System

• The xylem transports water and dissolved minerals from the roots to the rest of the plant.
• The phloem transports dissolved sugars and other organic compounds from leaves to the rest of the plant.

Photosynthesis

• Photosynthesis is the process in which plants use sunlight, carbon dioxide and water to produce glucose and oxygen.
• Three major sets of reactions in photosynthesis are light reactions, carbon fixation, and Calvin cycle.

Respiration

• Respiration is the process of releasing energy from glucose which happens in every cell in the plant.

Transpiration

• Transpiration is the movement of water through a plant, from the roots through the xylem and out into the air.

Plant Growth and Development

• Phototropism is a plant’s response to light; geotropism is a plant’s response to gravity; thigmotropism is a response to touch.
• Growth hormones like auxins, gibberellins, and cytokinins control plant growth.

Reproduction and Dispersal

• Flowering plants reproduce sexually by pollination, fertilisation, and seed dispersal.

Adaptations

• Plants have adapted to an extraordinary range of habitats and environmental conditions. For example, cacti have adapted to survive in hot, dry environments.