Download Class 7 Science Nutrition in Plants Notes in PDF format. All Revision notes for Class 7 Science have been designed as per the latest syllabus and updated chapters given in your textbook for Science in Class 7. Our teachers have designed these concept notes for the benefit of Class 7 students. You should use these chapter wise notes for revision on daily basis. These study notes can also be used for learning each chapter and its important and difficult topics or revision just before your exams to help you get better scores in upcoming examinations, You can also use Printable notes for Class 7 Science for faster revision of difficult topics and get higher rank. After reading these notes also refer to MCQ questions for Class 7 Science given on studiestoday
Revision Notes for Class 7 Science Chapter 1 Nutrition in Plants
Class 7 Science students should refer to the following concepts and notes for Chapter 1 Nutrition in Plants in Class 7. These exam notes for Class 7 Science will be very useful for upcoming class tests and examinations and help you to score good marks
Chapter 1 Nutrition in Plants Notes Class 7 Science
Functioning (Opening and Closing) of Stomata
Stomata open into small air cavities inside the leaves. Each stomata is guarded by two kidney shaped guard cells. The main function of stomata is to let the CO2 from atmosphere enter the leaf for photosynthesis. During the day time when photosynthesis takes place, stomata remain open.
At night when, there is no light and no photosynthesis takes place, the stomata get closed to avoid loss of water by transpiration.
The opening and closing of stomata is carried out by guard cells. In sunlight water from surrounding cells diffuses into the guard cells. The guard cells became turgid by the accumulation of water, their outer thin walls bulge out and the inner thick walls are drawn apart. The stomatal opening betwene the two guard cells widens making the stoma open. At the time of closing of stomatal opening, water diffuses out of the guard cells. The guard cells become of flaccid, their inner thick walls became straight and stomata get closed.
Synthesis of Nutrients other than Carbohydrates
Plant synthesise only glucose (simple carbohydrate) through photosynthesis. These simple carbohydrates are then used for the synthesis of other nutrients like proteins and fats.
Complex carbohydrates and fats are synthesised from simple carbohydrates.
Plants needs nitrogen for the synthesis of proteins. Though nitrogen is present in abundance in gaseous form in the air, plants cannot use these free nitrogen. They can absorb only the nitrate compounds along with water. The soil contains some nitrifying bacteria. These bacteria prepare nitrate compound from the nitrogen and enrich the soil with nitrates. Farmers add nitrogen rich fertilizers (like urea and ammonium sulphate) to the soil to increase its fertility.
No te: 1. Nitrogen rich fertilisers provide nitrogen to the soil. Plants obtain nitrogen from soil and use it for protein synthesis. Proteins are needed for plant growth.
2. Coloured leaves of coleus which are red, brown or with patches of brown and pink also have chlorophyll. But their green pigment is marked by the abundance of other pigments..
How nutrients are replenished in the soil
Soil supplies nutrients to the plants for growth. When crops are growing they absorb nutrients from the soil. This results in loss of nutrients in the soil and soil losses its fertility. The soil has to maintain its fertility to grow well. So, the nutrients need to be restored or replenished in the soil.
Nutrients are replenished in the soil by
• Addition of manures and fertilizers in the soil. Manures are normally added to the soil before sowing the seeds. Fertilizers are added when crops are growing. Fertilizers contain nitrogen, potassium and phosphorous.
• Legumious plants such as gram, peas, beans, etc have root nodules in which Rhizobium bacteria are present. These bacteria can take atmospheric nitrogen and convert it into a usable soluble form. Plants can use this nitrogen for making protein.
Heterotrophic Modes of Nutrition in Plants
Non green plants like fungi, some bacteria and some flowering plants are without chlorophyll. They cannot synthesis their food by photosynthesis. Like animals, they depend on green plants for their food. Such non green plants are called heterotrophs and their mode of nutrition is called heterotrophic nutrition.
Based on the method of obtaining food, heterotrophic plants may be
• Parasitic plants
• Saprophytic plants
• Insectivorous plants
• Symbiotic plants
Parasitic Plants
Non-green plants that obtain their food from some other green plants are called parasitic plants. The plant that provides food is called the host plant. The parasitic plants absorb food from the root or the stems of host plant. They develop special roots called haustoria which penetrate the host tissues and reach the vascular bundles. Some parasitic plants are total parasites. While others may be partial parasites.
Total parasitic plants completely depend on the host plant for their food. For example Dodder (cuscuta - amarbel) and Apodanthes are common total parasitic plants.[Fig. 3]
Partial parasitic plants have green leaves and can synthesis their food. They depend on the host for water and minerals. Mistletoe is a partial parasite. [Fig. 4]
The plant that bears the largest flower in the world is a parasitic plant. Its flower may be 106 cm in diameter and about 10 kg in weight. The plant has no leaves. It was discovered by Sir Stamford Raffles on a tour to Sumatra and hence is named after him as Rafflesia. [Fig . 5]
Note: The parasitic plants obtain food from host plant and thus interrupt food supply of the host. This weakens the host plant. Cuscuta covers woody plants and causes great damage to timber industry.
Saprophytic Plants
Saprophytic plants or saprophytes obtain their food from dead and decaying plants and animals. They release digestive enzymes on the decaying matter or animal excreta to break down their complex organic compounds into simple ones. These simple organic compounds are absorbed by the saprophytes Fungi such as bread mould and mushrooms, and some bacteria have saprophytic nutrition.
Q1 Define the following terms
1 Nutrition-It is the mode of taking food by an organism and its utilization by the body.
2 Autotrophic Nutrition-The mode of nutrition in which organisms make food themselves from simple substances is called autotrophic nutrition
3 Heterotrophic Nutrition-The mode of nutrition in which organisms depends on others for their food is called heterotrophic nutrition.
4 Photosynthesis-It is the process by which green plants can prepare their own food in the presence of sunlight, carbondiooxide, water, minerals and chlorophyll.
Q2 How are water and minerals absorbed by roots reach the leaves?
A Water and minerals are transported to the leaves by the vessels which run like pipes throughout the root, stem, branches and leaves.
Q3 List down the requirements of photosynthesis?
A .Requirements of photosynthesis are-
1 Carbon dioxide –is taken through stomata’s
2 Water and minerals- are transported to the leaves by the vessels.
3 Chlorophyll-is present in the leaves of the plants.
4 Sunlight-is absorbed by the chlorophyll present in the leaves.
Q4 Can Spirogyra prepare its own food. If yes how?
A Spirogyra can prepare its own food with the help of chlorophyll.
Q5 In what form plants prepared and stored their food?
A Plants prepared their food in the form of sugar and stored in form of starch.
Q6 Define the term hetrotrophic nutrition.
A It is a type of nutrition in which organisms depend on others for their food.eg rat
Q7 Differentiate between
a) parasites and saprophytes
b) parasite and host Parasites Saprophytes
Q8What are insectivorous plants? How do they obtain their food?
A Insectivorous plants are those plants which eat insects.
Q9 How does pitcher plants obtain their food?
A In pitcher plant pitcher like structure is the modified part of the leaf. The apex of the leaf forms a lid which can open and close the mouth of the pitcher. Inside the pitcher there are hairs which are directed downwards.When an insect lands in the pitcher, the lid closes and the trapped insects get entangled into the hair. The insect is digested bythe digestive juices secreted in the pitcher.
Q10 Identify the mode of nutrition in the followinga)
a) Cuscuta -Parasitic mode of nutrition
b) Mushroom-saprophytic mode of nutrition
c) Spirogyra- Autotrophic mode of nutrition
Q11What is symbiotic relationship?
A Some organisms live together and share shelter and nutrients. This is called symbiotic relationship.
Q12 Name two commonly growing saprophytes.
A Two commonly growing saprophytes are-
Bacteria, fungi.
Q13 Howdo saprophytes obtain nutrition?
A They secrete digestive juices on the dead decayed and decaying matter and convert it into solution. Then they absorb the nutrients fromit.
Q14 Hownutrients are replenished in the soil?
A Nutrients are replenished in the soil IN THE FOLLOWINGWAYS-
1 Fertilizers
2 Manures
3 Rhizobium
Q15 Howdoes Rhizobiumhelp a farmer?
A Rhizobiumis a bacteria that lives in the root nodules of leguminous plants like pea, moong, beans .It takes atmospheric nitrogen and convert it into a soluble form which is then utilized by plants.
Q16Lichens exhibit symbiotic relationship. Comment.
A In lichens algae and fungus live together. The fungus provides shelter ,water and minerals to the alga and in return the alga provides food which it prepares by photosynthesis.
Q17 Draw a well labeled diagram of cross section of leaf .
Q 18 Draw a well labeled diagram of stomata.
Please click the link below to download pdf file for Class 7 Science Nutrition in Plants Advanced Notes
Class 7 Science Nutrition in Plants Notes |
Class 7 Science Nutrition in Animals Notes |
Class 7 Science Fibre to Fabric Notes |
Class 7 Science Heat Notes |
CBSE Class 7 Science Acids Bases and Salts Notes |
CBSE Class 7 Science Physical And Chemical Changes Notes |
Class 7 Science Weather Climate Adaptations of Animals to Climate Notes |
Class 7 Science Winds Storms and Cyclones Notes |
Class 7 Science Soil Notes |
Class 7 Science Respiration in Plants and Animals Notes |
Class 7 Science Transportation in Animals and Plants Notes |
Class 7 Science Reproduction in Plants Notes |
Class 7 Science Motion and Time Notes |
Class 7 Science Electric Current and its Circuits Notes |
Class 7 Science Light Notes |
Class 7 Science Forests Our Lifeline Notes |
Class 7 Science Waste Water Story Notes |
CBSE Class 7 Science Chapter 1 Nutrition in Plants Notes
We hope you liked the above notes for topic Chapter 1 Nutrition in Plants which has been designed as per the latest syllabus for Class 7 Science released by CBSE. Students of Class 7 should download and practice the above notes for Class 7 Science regularly. All revision notes have been designed for Science by referring to the most important topics which the students should learn to get better marks in examinations. Our team of expert teachers have referred to the NCERT book for Class 7 Science to design the Science Class 7 notes. After reading the notes which have been developed as per the latest books also refer to the NCERT solutions for Class 7 Science provided by our teachers. We have also provided a lot of MCQ questions for Class 7 Science in the notes so that you can learn the concepts and also solve questions relating to the topics. We have also provided a lot of Worksheets for Class 7 Science which you can use to further make yourself stronger in Science.
You can download notes for Class 7 Science Chapter 1 Nutrition in Plants for latest academic session from StudiesToday.com
Yes, the notes issued for Class 7 Science Chapter 1 Nutrition in Plants have been made available here for latest CBSE session
There is no charge for the notes for CBSE Class 7 Science Chapter 1 Nutrition in Plants, you can download everything free of charge
www.studiestoday.com is the best website from which you can download latest notes for Chapter 1 Nutrition in Plants Science Class 7
Come to StudiesToday.com to get best quality topic wise notes for Class 7 Science Chapter 1 Nutrition in Plants