1. Answer the following Questions. (8 marks) 1. Explain why leaves are called food factories of plants with suitable diagram. 2. Distinguish between :- a) Parasites and Saprotrops b) Convex lens and concave lens 3. Draw a labelled diagram of human digestive system. 4. What are the different sources of wool? 5. Write the laws of reflection.
Answers
1. Answer:
Plants can perform photosynthesis only through leaves and not by other parts of the plant. Leaves have a special green pigment called chlorophyll which helps in the absorption of energy from the sun. The chloroplast present in the cells play a vital role in this process.
The various steps involved in the process of photosynthesis are given below:
1.) Absorption of light energy through the sun by chlorophyll present in leaves.
2.) Conversion of light energy chemical energy. In this process, the water molecule splits into its respective components hydrogen and oxygen.
3.) Carbon dioxide is reduced into carbohydrates like glucose by light energy utilizing the hydrogen and oxygen produced in the above step.
2.Answer
Parasites are the entities growing/inhabiting the body of the host, deriving nutrients from them. As a result, they are provided with ready-made food from the host’s body and can cause considerable harm to the host as they are directly dependent on them. Without a host, parasites cannot thrive and multiply. Hence, they do not kill the host but can harm, causing diseases, a few of which can be fatal. Unlike predators, parasites are much smaller than their hosts as they rapidly multiply. Cuscuta plant, flukes, ticks are some examples of parasites.
On the other hand, Saprotrophs are the living entities that derive their nutrition from the dead and decaying organic matter. Saprothrophs do not require a host. As they derive nutrition from dead matter, they are often termed as cleaning agents. Fungi and a few other bacteria are good examples of saprotrophs.
3 Answer
4 Answer
Wool is the textile fibre obtained from sheep and other animals, including cashmere and mohair from goats, qiviut from muskoxen, hide and fur clothing from bison, angora from rabbits, and other types of wool from camelids. Wool consists of protein together with a small percentage of lipids
5.Answer
Any mirror obeys the three laws of reflection, flat, curved, convex or concave
The law of reflection states that the angle of reflection equals the angle of incidence—θr = θi. The angles are measured relative to the perpendicular to the surface at the point where the ray strikes the surface
