1. What type of microscope would you need to view a cellular structure that is 5 nm in size?
A. a light microscope
B. an electron microscope
C. a compound microscope
D. no microscope can resolve down to 5 nm
An electron microscope is a type of microscope that uses electrons to illuminate a specimen and create an enlarged image. Some electron microscopes can magnify specimens up to 2 million times
2. Which of the following statements is incorrect?
A. DNA in the nucleus is usually coiled into chromosomes.
B. The nucleolus is the site of ribosomal RNA synthesis.
C. Some substances can pass into and out of the nucleus.
D. Red blood cells cannot synthesize RNA.
Chromatin fiber is coiled into a structure called a “solenoid”. This fiber is then looped and coiled yet again, leading finally to the familiar shapes known as chromosomes.
3. According to Dalton’s atomic theory the smallest particle which can exist independently is–
A. An atom
B. A molecule
C. A cation
D. An anion
4. The major ingredient of leather is–
D. Nucleic acid
5. The fastest acting enzyme in the biological kingdom is–
D. carbonic anhydrase
Carbonic anhydrase plays a key role in the regulation of pH and fluid balance in different parts of our body.
6. Glass is made from the mixture of–
A. Quartz and mica
B. Sand and salt
C. Sand and silicates
D. None of these
7. Which of following is used as a filter in rubber tyres?
D. Carbon Black
It is used in tires, rubber and plastic products, printing inks and coatings is related to properties of specific surface area, particle size and structure, conductivity and colour.
8. Vitamins are–
A. inorganic substances which cannot be synthesized by animals
B. inorganic by animals
C. organic substances that cannot be generally synthesized by animals
D. organic substances which can be commonly synthesized by animals
9. Which of the following is a physical change?
Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase.
10. The chemical used as a fixer in photography is–
B. Sodium thiosulphate
C. Sodium Sulphate
D. Ammonium persulphate
The sodium thiosulfate is known as a photographic fixer, and is often referred to as hypo, from the original chemical name, hyposulphite of soda.