Experts have designed these Class 7 Science Notes Chapter 10 Life Processes in Plants Class 7 Notes for effective learning.
Class 7 Science Chapter 10 Life Processes in Plants Notes
Class 7 Life Processes in Plants Notes
Class 7 Science Chapter 10 Notes – Life Processes in Plants Notes Class 7
→ All living beings grow and need food for their growth and development.
Animals eat food to grow. Food provides nutrients like carbohydrates, fats, proteins, vitamins and minerals, which along with water are essential for growth.
→ Growth in Plants: Unlike animals, plants do not need food. Plants use carbon dioxide and water in the presence of sunlight and chlorophyll to produce glucose and oxygen. This process is called photosynthesis.
As the plants grow, new leaves and branches emerge, height increases, stem thickens, flowers and fruits are formed.
→ Growth in plants means more than just getting taller: As plants grow, we see new leaves, flowers, and branches. Their stems become thicker, and their roots grow deeper into the soil.
→ Sunlight and water are essential for growth: Experiments show that a plant without water or sunlight cannot grow well. Sunlight provides energy, and water helps early nutrients from roots through thin tubes called xylem to all parts of the plant.
→ Leaves are the plant’s kitchen:
Most food is made in the leaves of the plant, so they are often called the “food factories”. The green pigment chlorophyll is essential for photosynthesis.
→ Photosynthesis- Plants’ food- synthesising process: In this process, plants take in carbon dioxide from the air, water from the soil using a green pigment called chlorophyll, in the presence of sunlight, synthesise glucose and oxygen is released.
→ Chlorophyll- The green pigment: Leaves are green due to chlorophyll pigment. It helps the leaf trap sunlight, which is then used to make food.
→ Photosynthesis by chlorophyll and other pigments
Some plant leaves appear red, violet or brown because they contain more of these coloured pigments than the green coloured chlorophyll. This hides the green colour. Some of these pigments also help in photosynthesis.
→ Plants take in carbon dioxide through tiny holes: Plants take in this invisible gas through tiny holes in their leaves called stomata. It is one of the key ingredients for preparing food by photosynthesis.
→ Oxygen is a by-product of photosynthesis: While making food, plants also release oxygen, which we need to breathe. So, plants actually clean our air!
→ The Simple Equation of Photosynthesis
→ Plants store food as starch:
The glucose synthesised during photosynthesis is either used right away for energy or stored as starch in leaves, roots (like sweet potatoes), stems (like potatoes), and fruits.
→ Stomata help in exchange of gases: These are tiny pores on the lower side of leaves that open and close for exchange of gases like carbon dioxide and oxygen.
→ Transport system in plants:
xylem and phloem
- Xylem carries water and minerals from roots to leaves.
- Phloem distributes the food (glucose) made in leaves to all parts of the plant.
→ Plants also need energy: Just like us, plants break down glucose to get energy. This is called respiration, and it happens all the time, even at night.
→ Every part of a plant respires: From the smallest root to the tallest branch, all parts of a plant need energy, so they all carry out respiration.
→ Carbon dioxide is released during respiration:
During respiration, plants break down glucose in the presence of oxygen and carbon dioxide, water and energy are formed similar to animals and humans.
→ Photosynthesis keeps our air clean: Plants absorb carbon dioxide (a gas we exhale) and release oxygen during photosynthesis. This keeps a balance in the air and makes life possible.
→ Photosynthesis and respiration go hand in hand: During the day, plants synthesise food and release oxygen through photosynthesis. All day and release night, they use food to release energy during respiration. Respiration is a continuous process and occurs throughout day and night.
→ Plants support life on Earth:
Without plants, we wouldn’t have food to eat or air to breathe. They are the foundation of life on Earth, feeding not only themselves but also animals and humans.
→ Photosynthesis: The process by which plants make their own food using sunlight, carbon dioxide, and water.
→ Chlorophyll: The green pigment in leaves that captures sunlight for photosynthesis.
→ Starch: A form of stored food in plants, made during photosynthesis.
→ Glucose: The simple sugar produced during photosynthesis that provides energy.
→ Xylem: The plant tissue that transports water and minerals from the roots to the leaves.
→ Phloem: The plant tissue that transports food from the leaves to other parts of the plant.
→ Stomata: Tiny pores on the leaves that help in the exchange of gases (oxygen and carbon dioxide).
→ Respiration: The process by which plants break down glucose to release energy.
→ Carbon dioxide (CO2): A gas taken in by plants from the air to use in photosynthesis.
→ Oxygen (O2): A gas released by plants during photosynthesis and used in respiration.
→ Sunlight: The natural light energy needed by plants for photosynthesis.
→ Leaf: The main site, of photo-synthesis in a plant, often called the “food factory.”
→ Nutrients: Essential substances (like minerals) absorbed from the soil to help plants grow.
→ Growth: The increase in size, number of leaves, and height in a plant, supported by food and energy.
→ Roots: The parts of the plant that grow underground, absorbing water and minerals from the soil.
→ Stem: The main supporting stalk of a plant, which helps in transporting water and nutrients.
→ Mind Map:
Photosynthesis
Carbon Dioxide + Water + Light — Glucose + Oxygen
Photosynthesis is the process in which green plants, algae, and some bacteria use sunlight, water, and carbon dioxide to make their own food, Herbivores obtain energy by eating these plants and in turn, carnivores eat the herbivores. As a foundational part of the food chain, almost all living organisms rely on photosynthesis.
