class ten ncert science activities chapter 6
Answers
Explanation:
Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
Answer. In multi-cellular organisms like humans, various body parts have specialized in the functions they perform. All the cells with in different parts of human body need oxygen but all are not exposed to surrounding environment for intake of oxygen through diffusion. Therefore, process of diffusion is insufficient to meet the oxygen requirements of multi-cellular organisms like human
Question 2. What criteria do we use to decide whether something is alive?
Answer. Living organisms are well-organized structures. Due to the effects of the environment, this organized structures of living organisms is very likely to keep breaking down over time. If order breaks down, the organism will no longer be alive. So living creatures must keep repairing and maintaining their structures. As all these structures are made up of molecules, they must carry out effective movement of molecules around all the time. This invisible molecular movement with in living organism is necessary criteria to decide whether something is alive
Question 3. What are outside raw materials used for by an organism?
Answer. For maintenance, growth and reproduction, an living organism needs energy, which is produced from outside raw materials through process of nutrition. These outside raw material are :
Food : Since life on earth depends on carbon based molecules, most of these food sources are also carbon-based. Different organisms, Depending on the complexity of these carbon sources, can use different kinds of nutritional processes
Oxygen : The oxygen is acquired from outside the body, and is used for the break-down of food sources for cellular needs by using process of respiration
Water : Water forms an essential part in facilitating most of the functions with in a living organism
Question 4. What processes would you consider essential for maintaining life?
Answer. The processes essential for maintaining life are :
Nutrition
Respiration
Transport of materials
Excretion of waste products
Activity 6.1 | Page 96 | Chapter 6. Life Processes| CBSE Class X (10th) Science
Take a potted plant with variegated leaves – for example, money plant or crotons.
Keep the plant in a dark room for three days so that all the starch gets used up.
Now keep the plant in sunlight for about six hours.
Pluck a leaf from the plant. Mark the green areas in it and trace them on a sheet of paper.
Dip the leaf in boiling water for a few minutes.
After this, immerse it in a beaker containing alcohol.
Carefully place the above beaker in a water-bath and heat till the alcohol begins