This PSEB 7th Class Science Notes Chapter 1 Nutrition in Plants will help you in revision during exams.
PSEB 7th Class Science Notes Chapter 1 Nutrition in Plants
→ For all living things such as plants, animals, human beings food is necessary.
→ The main components of food are carbohydrates, fats, protein, vitamins, and minerals which are important for the building and growth of the human body.
→ The process of taking in food and using it for growth and development is called nutrition.
→ Different organisms require different types of nutrition.
→ On the basis of habits of intake of nutrients, nutrition can be divided into two types:
- Autotrophic nutrition
- Heterotrophic nutrition
→ Organisms that use simple inorganic matters and prepare their food on their own are called Autotrophs and the nutrition produced by them is called autotrophic nutrition.
→ All green plants and bacteria are Autotrophs.
→ Organisms that depend upon other organisms for food to survive are called Heterotrophs.
→ All animals, humans, and certain types of fungi are heterotrophs.
→ Euglena is a type of organism which produces both autotrophic nutrition as well as heterotrophic nutrition.
→ Leaves are called the food factory of plants.
→ Leaves produce their food by photosynthesis. During photosynthesis in green plants, the green coloured pigments (chlorophylls) are capable of trapping sunlight and taking carbon dioxide (CO2) from the air in the presence of water to produce food in the form of carbohydrates.
→ The leaves of the plants have tiny pores on their top layer, through which the carbon dioxide (taken in) and oxygen (given out) are exchanged and these exchange pores are called stomata.
→ Stomata are surrounded by the guard cells.
→ Soil provides water and minerals to plants, which are absorbed by the roots of the plants through Xylem tissues present in roots and further sent to other parts of the plant.
→ Sun is the main source of energy for all living organisms.
→ In the photosynthesis process, the energy of the sun is converted into chemical energy.
→ The leaves of some plants are not green in colour but of some other colour as for example red leaves of coleus, red cabbage has violet leaves.
→ Such leaves also show photosynthesis because they also contain chlorophylls but are lesser in amount than green plants.
→ The basic products of photosynthesis are oxygen and glucose.
→ Heterotrophs are divided into four types:
- Decomposers
- Parasites
- Insect eaters
- Symbiotic
→ The organisms that get nourishment from the body of other living beings are called parasites.
→ Organisms that depend on dead bodies and rotten substances for their nourishment are called decomposers.
→ In a symbiotic relationship, two types of organisms depend on each other for food, from which both the organisms are benefited.
→ Dead and decaying plants and animals are decomposed by the decomposers which provide essential nutrients to the soil.
→ Nutrients: The main components of food such as carbohydrates, fats, proteins, vitamins, and minerals that help in the growth and development of the body are called nutrients.
→ Self-nutrition: Organisms that make their own food from simple substances are called self-nourishment. This type of nutrition is called autotrophic nutrition.
→ Heterotrophic nutrition: Organisms that can’t prepare their own food but depend on other organisms are called Heterotrophs and this type of nutrition is called heterotrophic nutrition.
→ Dead food: A diet in which dead creatures or rotten substances are providing food to other organisms.
→ Parasites: Organisms that depend on other plants and organisms for food are called parasites.
→ Photosynthesis: This is an activity in which the leaves of a plant contain green colour pigment-chlorophyll, carbon dioxide of the air, and water in the presence of sunlight prepare food in the form of carbohydrates. Here solar energy is converted into chemical energy.
→ Chlorophyll: This is a green pigment that is present in plants. This is important for plants to prepare their own food.
→ Carbohydrates: A type of micronutrient that is present in many foods such as sugar, starch, and fiber. Our body needs these micronutrients to stay healthy.
→ Stomata: Stomata are found on the outer surface of the aerial parts of the plant. The maximum amount of stomata is found on leaves. Gases are exchanged through Stomata (holes).
→ Host: The plants or organisms on which the parasite depends for its food are called the host.
→ Chemical Fertilizer: This is a factory-made chemical (a mixture of inorganic salts). It contains a lot of nutrients for plants. It fulfills the deficiency in the soil so that the soil remains fertile.
→ Rhizobium: A Bacterium found in the roots and buds of leguminous plants. It makes the nitrogen in the air usable, which is used by plants, and in return, plants provide shelter and food to this bacteria.