Watch the video on natural resources and coal to learn:
By: Edunetworking
Class 8th Science Chapter 2 Summary
Watch these videos to learn:
Micro Organisms:
By: Simple Science
Viruses:
By: Khan Academy
Class 8th Science Chapter 1 Notes
- In order to provide food to our growing population, we need to adopt certain agricultural practices.
- Same kind of plants grow and cultivated at a place constitute a crop.
- In India, crops can be broadly categorized into two types based on seasons - rabi and kharif crops.
- It is necessary to prepare soil by tilling and levelling, ploughs and levellers are used for this purpose.
- Sowing of seeds at appropriate depths and distances gives good yield. Good variety of seeds are sown after selection of healthy seeds. Sowing is done by seed drills.
- Soil needs replenishment and enrichment through the use of organic manure and fertilizers. Use of chemical fertilizers has increased with the introduction of new crop varieties.
- Supply of water to crops at appropriate intervals is called irrigation.
- Weeding involves removal of unwanted and uncultivated plants called weeds.
- Harvesting is the cutting of the manure crop manually or by machines.
- Separation of the grains from the chaff is called threshing.
- Proper storage of grains from the chaff is called threshing.
- Proper storage of grains is necessary to protect them from pets and microorganisms.
- Food is also obtained from animals for which animals are reared. This is called animal husbandry.
Class 9th Biology Chapter 7 Notes
Diversity in Living Organisms Videos by Exam Fear:
- Classification helps us in exploring the diversity of life forms.
- The major characteristics considered for classifying all organisms into five major kingdoms are:
- Whether they are made of prokaryotic or eukaryotic cells.
- Whether the cells are living singly or organised into multi-cellular and thus complex organisms.
- Whether the cells have a cell-wall and whether they prepare their own food.
- All living organisms are divided on the above bases into five kingdoms, namely Monera, Protista, Fungi, Plantae and Animalia.
- The classification of life forms is related to their evolution.
- Plantae and Animalia are further divided into subdivisions on the basis of increasing complexity of body organisation.
- Plants are divided into five groups : Thallophytes, Bryophites, Pteridohytes, Gymnosperms and Angiosperms.
- Animals are divided into ten groups: Porifera, Coelentrata, Platyhelmenthis, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata, Protochordata and Vertebrata.
- The binomial nomeclature makes for a uniform way of identification of vast diversity of live around us.
- The binomial nomeclature is made up of two words - a generic name and a specific name.
Class 9th Biology Chapter 6 Tissue Notes
A video on Tissues by LearnNext:
Notes:
- Tissue is a group of cells similar in structure and function.
- Plant Tissues are of two main types - meristematic and permanent.
- Meristematic tissue is the dividing tissue present in the growing regions of the plant.
- Permanent tissues are derived from meristematic tissue once they lose the ability to divide. They are classified as simple and complex tissues.
- Perenchyma, collenchyma and sclarenchyma are three types of complex tissues.
- Animal tissues can be epithelial, connective, muscular and nervous tissue.
- Depending on shape and function, epithelial tissue is classified as squamous, cuboidal, columnar, ciliated and glandular.
- The different types of connective tissues in our body include areolar tissue, adipose tissue, bone, tendon, ligament, cartilage and blood.
- Striated, unstriated and cardiac are three types of muscle tissues.
- Nervous tissue is made of neurons that receive and conduct impulses.
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