Plant Physiology

Plant physiology is the study of how plants work. It looks at how plants grow, take in nutrients, and how they respond to their environment. This field focuses on understanding the processes inside plants at the smallest levels, such as in cells and molecules.

As plants adapted to live on land, they needed special methods to survive, like handling water and carbon dioxide differently.

Microbes in Human Welfare

Plant physiology covers various plant parts and how they function. It helps us understand important processes in plants, including photosynthesis (how plants make food), how they take in minerals, how they breathe (respiration), how they move nutrients around (transportation), and overall plant growth and development.

Plant Parts and Functions

Plants have different parts like roots, stems, leaves, flowers, and fruits. Each part has its own function:

Roots

• Roots keep the plant anchored in the soil.
• They absorb water and minerals from the soil.
• Roots help in plant growth and store food.
• They ensure the plant stays in one place and provides nutrition.

Stem

• The stem is above the ground; older stems are brown, and younger ones are green.
• It supports photosynthesis by holding leaves up to the light.
• The stem provides structure and helps the plant grow into a tree.
• It carries water, minerals, and food to different parts of the plant.
• The stem protects the xylem and phloem, which transport water and nutrients.

Leaves

• Leaves are vital for photosynthesis, using sunlight, carbon dioxide, and water to make food.
• They have three parts: leaf base, lamina, and petiole.
• Main functions of leaves:
  1. Transpiration: Removes excess water through tiny pores called stomata.
  2. Photosynthesis: Produces food using water and carbon dioxide with sunlight.
  3. Reproduction: Some leaves help in reproduction, like Bryophyllum leaves that produce new plants.

Genetics & Evolution

Flowers

• Flowers are the colorful and attractive part of the plant.
• They are responsible for reproduction.
• A flower has petals, sepals, stamens, and carpels.
• Petals are colorful, sepals are green, and stamens and carpels are the male and female reproductive parts.

Fruits

• Fruits develop from the fertilized ovary of the plant.
• The mature ovary produces seeds which develop into fruits.
• Some fruits, called parthenocarpy fruits, develop without fertilization.

Ecology and Environment 

Nutrition Transportation in Plants

Plants have a system called xylem and phloem that helps move nutrients and water from the roots to all parts of the plant. This process is called translocation. The transport of water and nutrients in plants can go in one direction or multiple directions. There are two main ways of transportation: passive, which happens through diffusion (specifically facilitated diffusion), and active, which involves specific proteins in the membrane called pumps.

Mineral Nutrition in Plants

Plants need certain minerals to grow well. These minerals help identify what plants need to stay healthy. They show signs of what’s missing and how plants take in these nutrients. These nutrients are crucial for important processes like keeping cell membranes working, maintaining cell sap concentration, and enzyme activity. Macro and micronutrients in plants are vital for these functions.

Class 11 Biology Plant Physiology Mind Map - Download PDF

Students download the Class 11 Biology Plant Physiology mind map to easily understand and revise complex topics quickly. It helps them grasp key concepts and connections at a glance.