CBSE Pathshala

Short Answer Type Questions (2 marks each) Q. 1. List four gases generated in a biogas plant Ans. (i) Hydrogen (ii) Hydrogen sulphide (iii) Methane (iv) Carbon dioxide. Q. 2. Name the major constituent of biogas. List three characteristics to prove it as an excellent fuel. Ans. Methane is the major constituent of biogas. Three characteristics to prove it as an excellent fuel : (i) Smokeless (ii) Leaves no residue (iii) Higher heat of combustion. Q. 3. Mention the main use of slurry left behind in the biogas of plant. State the characteristics of the slurry on which this use is based. Ans: Slurry is used as a manure as it is rich in nitrogen and phosphorus. Q.4. List any four reasons why we need to look for alternate sources of energy. Ans: Four reasons we need to look for alienate sources of energy are : (a) Pollution due to fossil fuels. (b) Exhausting fuel reserves.(c) Increasing need. (d) Replenishment is not easy. Q.5. List any four qualities of an ideal so...

Q  Name the cells having branches structure. Ans Nerve Cell. Q Why cells could not be observed before seventeenth century? Ans Cells could not be observed before seventeenth century because till that time microscope was not invented. Q Why plant cell have cell wall? Ans Plant cells need protection against variations in temperature, high wind speed, atmospheric moisture, etc. They are exposed to these variations because they cannot move. That's why they have cell wall. Q Which organism has the smallest cell? Ans  Mycoplasmas, a bacteria has the smallest cell of the size of 0.1 micron i.e. ten thousandth part of a mill metre. ' Q  Which is the largest cell visible by unaided eye? Ans Ostrich egg has the largest visible cell by unaided eye. Q Name the four elements, which fonn major part of protoplasm. Ans These are carbon, hydrogen, oxygen and nitrogen. Q Give two examples of prokaryotes. Ans Bacteria and blue green algae. Q  Name the la...