STD X – PLANT PHYSIOLOGY – NEWTON

Absorption by the Roots

Water is very crucial for plants for different metabolic activities. One of the most significant functions of the roots is to absorb water and minerals from the soil. Terrestrial plants obtain their water supply from the soil. The method of water absorption by the roots from the soil is known as “mechanism of water absorption”. The two processes involved in absorption are:

Active absorption.

Passive absorption.

Absorption of water and other essential nutrients takes place in water with the help of roots and leaves.

In this chapter, you will learn about absorption by roots.

Cell sap: A solution contained inside the cell vacuole containing dissolved salts.

Semi-permeable membrane: A thin membrane which selectively allows the movement of certain molecules in and out of the cell.

Absorption and Conduction of Water and Minerals

All plants essentially require food, minerals and water. The transport system in plants is responsible for distribution of food, minerals and water to all part of the plant.

In this chapter, you will learn all about absorption and conduction in plants along with the definition of associated terms involved in the process.

Root Pressure and Importance of Root hairs

The force that helps to carry fluids up into the xylem,  which are the water conducting vessels is known as the root pressure.  Root hair cells are protrusions at the tip of the plant’s roots. Root hairs are an essential part of root through which plants absorb water and nutrients. They have a huge surface area, thus making the absorption of water and minerals more efficient.

In this chapter, you will learn about root pressure and importance of root hair with the help of relevant diagrams.

Process of Photosynthesis

Imagine if you could go out in the Sun for an hour or two and use sun rays to recharge and function for the entire day! Unfortunately, we cannot, although plants and certain organisms can, using a process called Photosynthesis.

Plants and certain organisms use the process of photosynthesis to convert light energy into chemical energy for synthesising their own food. This energy is first stored in organelles called chloroplasts (double-membrane organelle) in plants and a green pigment present in chloroplasts called chlorophyll then processes the sunlight into energy.

Transpiration:

Transpiration is the loss of water due to evaporation that occurs through stomata in the leaves. It helps in transporting water and minerals, cools leaf surfaces by evaporative cooling and maintains the shape and structure of plants by keeping cells turgid.

The process involved in transpiration:

The process of transpiration occurs when water moves through plants from the roots to the leaves, then changes to vapour as it leaves the plant. Transpiration cools the plant and also provides it with nutrients, carbon dioxide and water.