⦁ What is life process?
Activities like respiration, nutrition, growth, movement, response to stimuli, excretion and reproduction is called as life process.
⦁ What is nutrition?
The process by which organisms obtain and utilize food is called as nutrition.
⦁ What are the types of nutrition?
There are two types of nutrition:
What are autotrophs?
The organisms who prepare their own food is called as autotrophs.
Example: all green plants.
⦁ What is autotrophic nutrition?
Green plants prepare their food by a process called photosynthesis.This mode of nutrition is called autotrophic nutrition.
EXPERIMENT : to show that carbon dioxide is necessary for photosynthesis.
⦁ Take two potted plants which are kept in a dark room for two days .
⦁ Mark one of pot as ‘A’ another pot as ‘B’.
⦁ Place a beaker containing potassium hydroxide solution near the plant ‘A’ and a beaker containing sodium bicarbonate solution near plant ‘B’.
⦁ Cover both the pots separately by bell jars or polythene bags.
⦁ Take precautions such that air does not enter the polythene bags.
⦁ Place both plants side by side in a well lit room for about 48 hours.
⦁ We can see that the leave of plant have starch.
⦁ Therefore we conclude that carbon dioxide is required for plants to prepare their own food in the form of starch.
⦁ What is stomata?
The minute openings are called stomata.
Carbon dioxide enters the plant body through stomata.
⦁ What is grana and stroma?
Grana and Stroma are the major regions of chloroplast.
⦁ What is light reaction?
Grana and stroma are involved in two different phases of photosynthesis called light dependent reaction which is also called light reaction.
⦁ What is dark reaction also called?
Dark reaction also called as light independent reaction.
⦁ Explain light dependent reaction.
- Light dependent reaction takes place in the present of sunlight, in the grana region.
- During this reaction water is decomposed into hydroxyl(OH-) and hydrogen (H+)ions in the presence of light energy.
- Oxygen is given out by plants in this phase
- Light energy is converted in to chemical energy and is stored in the form of ATP.
⦁ Explain light independent reaction.
⦁ In this reaction carbon dioxide is reduced to starch .
⦁ Utilizing the energy released during light dependent reaction.
⦁ This reaction takes place in the stroma region.
What are insectivorous plants?
The group of plants try to obtain nitrogen by other means , by trapping and digesting insects, such types of plants are called as insectivorous plants
Example: Drosera, Nepethes.
What is epiphytes?
The types of plants which grow with the support of the tree, such types of growing plants are known as epiphytes.
⦁ What are heterotrophs?
The organisms who cannot prepare their own food are called as heterotrophs. Their mode of nutrition is called heterotrophic nutrition.
⦁ What are saprophytes?
Fungi and bacteria which feed on organic matter by decomposing the nutrient supplement, thus these fungi and bacteria iare known as saprophytes .
⦁ What is decomposition?
Decomposition is the process by which the deacay and rotten matter are transformed into simpler organic matter.
⦁ What are parasites?
Parasites are animals or plants that lives in or with another animal or plant are called parasites.
Example: tapeworms, fleas, barnacles.
Nutrition in animals
⦁ Animals are heterotrophs
⦁ Holozoic is the type of nutrition found in animals
⦁ Holozoic nutrition involves five steps.
⦁ What is ingestion?
Animal takes in food by a process called ingestion.
⦁ What is digestion?
The food enter animal’s body ,that should be broken into simple form by the process called digestion.
⦁ What is absorption?
The digested food is absorbed and transported to cells cells and tissues through blood by the process called absorption.
⦁ What is assimilation?
Digested food is stored ,utilized in the cells by the process called assimilation.
⦁ What is egestion?
The process by which the undigested food particles are eliminated from animal body.
Nutrition in amoeba
⦁ Amoeba is a unicellular organism.
⦁ All the life activities takes place in the same cell .
⦁ It feeds on bacteria, diatoms, unicellular algae, minute protozoa, and zooplankton.
⦁ Amoeba is an omnivore.