Class 7 notes for exam
Answers
Explanation:
Ch - 1
essential notes :-
Food is essential for living organisms
Nutrients are 'taken in' through their food by living organisms and are utilised in their bodies.
This process of obtaining, and utilising food by an organism, is known as nutrition.
The process of obtaining food is not the same in all organisms.
there are 3 types of nutrition-
Heterotrophs
Autotrophs
Saprotrophs
Autotrophic nutrition- it includes plants as producers , which produce there own food.
Heterotrophic nutrition- Organisms dependent on another organisms for their food and survival .
Saprotrophic nutrition- organisms feed on dead and decaying matter.
Plant makes there own food by the process of photosynthesis.
It includes green colour pigment consisting chlorophyll, CO2 and sunlight .
Glucose in form of carbohydrates and O2 is produced during this process.
Symbiotic Relationship
2 organisms live in close association and develop a Relationship that benefits both organisms.
like, algae and fungi lives in Symbiotic Relationship.
Ch - 2
Essential notes
On basis of food habits organisms are classify into 3 types :
Herbivores
Carnivores
Omnivores
Herbivores - Dependent on plants .
Carnivores- Dependent on other animals
Omnivores- Eat plants as well as animals
Modes of nutrition in animals-
Saprotrophic nutrition
parasitic nutrition
Holozoic nutrition
Intake of food by digestive system-
Ingestion
Digestion
Absorption
Assilimation
Egestion
Besides these parts, there are a number of glands, associated with the alimentary canal, which play their roles in the process of digestion of food.
The salivary glands, pancreas and the liver, are the three main such glands.
Teeth or bucal cavity
Humans have 4 types of teeths
Incisors
Canines
Premolars
Molars
Tongue
Tongue is a muscular organ attached to the floor of the buccal cavity.
It is free to move at its front end where it can
move in all directions.
The tongue helps in mixing up of
saliva with food;
it also helps in swallowing food.
It has four types of taste buds which help
us to know about the-
sweet,
sour,
bitter
and salty tastes,
associated with different types of items, in our food.
Digestion includes -
Mouth
Food pipe
Stomach
Intestines
Intestines -
Small Intestine have Finger like projection called villi.
These villi increase surface area for Absorption pf digested food.
Nutrition in cud chewing animals
Cud chewing herbivore animals are called ruminants. Cow, deer,camel, buffalo, sheep and giraffe are some of the well-known ruminants.
They have a special four-chambered stomach.
Ch - 3
Essential notes
Matter exists in 3 states
Solid
Liquid
Gas
Matter is made up of small particles called atom
Atom combine to form molecules.
Like , H2 ( 2hydrogen atom) + O ( oxygen atoms)
= H20 ( which is a water molecule)
Pure substance is classified into 2 types
Element
Compound
A mixture is unpure substance
Chemical Formula-
For this you need to know Names of Elements amd symbols.
Hydrogen = H
Sodium = Na
Magnesium = Mg
Aluminium = Al
Calcium = Ca
Potassium = K
Iron = Fe
Copper = Cu
Gold = Au
Silver = Ag
Carbon = C
Oxygen = O
Sulphur = S
Nitrogen = N
Phosphorus = P
Chlorine = Cl
Bromine = Br
lodine = I
Answer:
Bro cannot understand your question.
Its incomplete, please tell the name of the chapter.