NCERT Solutions for Class 10 Science Chapter 6 Life Processes
Question 1. Class 10 Science Chapter 6
What processes would you consider essential for maintaining life?
Nutrition, respiration, transportation and excretion.
Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
In multicellular organisms, only the cells present in the surface layer are in direct contact with the surrounding environment, whereas other cells are not. Therefore, diffusion is insufficient to meet the oxygen requirements of multicellular organisms like humans.
What criteria do we use to decide whether something is alive?
Growth, movement or locomotion, response to, stimuli and ability to reproduce are the criteria that we use to decide whether something is alive.
What are outside raw materials used for by an organism?
The outside raw materials used for by an organism are:
(a) Food for obtaining energy.
(b) Oxygen to use it in the process of breakdown of food sources for cellular needs.
Where do plants get each of the raw materials required for photosynthesis?
Plants get carbon dioxide from atmosphere. It gets water and minerals from the soil.
What is the role of the acid in our stomach?
The acid (hydrochloric acid) formed in our stomach helps in killing unwanted harmful germs which may have gained entry along with the food. It is secreted by the gastric glands creates an acidic medium which facilitates the action of the pepsin enzyme.
What is the function of digestive enzymes?
The function of digestive enzymes is to hasten the process of digestion in which complex
molecules break down into simpler molecules which are then easily absorbed by the body.
What are the differences between autotrophic nutrition and heterotrophic nutrition?
Modes of Nutrition
1. Autotrophic Nutrition.
2. Heterotrophic Nutrition.
Raw Materials for Photosynthesis:
2. Chlorophyll: Sunlight absorbed by chloroplast
3. CO2: Enters through stomata, and oxygen (O2) is released as a byproduct through stomata on the leaf.
4. Water: Water + dissolved minerals like nitrogen, phosphorous etc., are taken up by the roots from the soil.
How do raw materials for photosynthesis become available to the plant?
1. Water comes from the soil, through the xylem tissue in roots and stems.
2. Carbon dioxide comes in the leaves through stomata.
Main Events of Photosynthesis
1. Absorption of light energy by chlorophyll.
2. Conversion of light energy into chemical energy + splitting (breaking) of water into hydrogen and oxygen.
3. Reduction of CO2 to carbohydrates.
4. Sunlight activates chlorophyll, which leads to splitting of the water molecule.
5. The hydrogen, released by the splitting of a water molecule is utilized for the reduction of carbon dioxide to produce carbohydrates.
6. Oxygen is the by-product of photosynthesis.
7. Carbohydrate is subsequently converted into starch and is stored in leaves and other storage parts.
8. The splitting of water molecules is a part of the light reaction.