Science [2 Mark Questions]

Use of Plastic cups raised the concern towards hygiene thus they were replaced by disposable plastic cups.
Plastic cups are non-biodegradable and harm the environment friendly. They were thus replaced by Kulhads.
Making Kulhad made of clay on a large scale resulted in the loss of top fertile soil.
Now, disposable paper cups are used because - the paper can be recycled, it is biodegradable and is eco-friendly material which does not cause environmental pollution.

a. The household waste or rubbish produced in our day-to-day life is called garbage. For example, spoilt food, vegetable peels, leaves, wood, grass, paper, plastic, etc.
Garbage is classified into the following two types:
i. Biodegradable garbage - Garbage that can be decomposed naturally. Examples - vegetable peels, leaves, paper, etc.
ii. Non-Biodegradable garbage - Garbage that cannot be decomposed naturally. Examples - metal, plastics, etc.
b. Catalyst , Enzymes are biological molecules, usually proteins, that catalyze chemical reactions by lowering the activation energy required for the reaction to occur. Each enzyme is designed to catalyze a specific chemical reaction, and it does so by recognizing and binding to a specific substrate or group of substrates.

a. If the egg is not fertilized it leads to menstruation.
b. Bacterial infection - Syphilis and Chlamydia
Viral infection - AIDS and Hepatitis.