Human beings hearing range is:

• 30 to 30,000 Hz
• 50 to 50,000 Hz
• 20 to 20,000 Hz
• 40 to 40,000 Hz
Correct Option: C  [ 20 to 20,000 Hz ]

Remark:

Saliva helps in the digestion of:

• fats
• starch
• proteins
• vitamins
Correct Option: B  [ starch ]

Remark:

Which of the following could be used as fuel in propellant of rockets?

• liquid hydrogen + liquid nitrogen
• liquid oxygen + liquid argon
• liquid nitrogen + liquid oxygen
• Liquid hydrogen + liquid oxygen
Correct Option: D  [ Liquid hydrogen + liquid oxygen ]

Remark:

In plants, meiotic cell division takes place in the:

• root tip
• shoot tip
• flowers
• fruits
Correct Option: C  [ flowers ]

Remark: Meiosis is a type of cell division in which the number of chromosomes is halved (from diploid to haploid) in the daughter cells, i.e., the gametes. In plant it takes place in Flower.

The longest cell in animals is

• Nerve cell
• Hepatocyte (Liver cell)
• Blood cell
• Muscle cell
Correct Option: A  [ Nerve cell ]

Remark:

The waves which can propagate even through the vacuum,are called __________.

• Mechanical waves
• Reverse waves
• Inverted waves
• Electromagnetic waves
Correct Option: D  [ Electromagnetic waves ]

Remark:

Muscle fatigue is due to accumulation of

• Carbon Dioxide
• Creatinine
• Lactic acid
• Ethyl alcohol
Correct Option: C  [ Lactic acid ]

Remark:

Which layer of the atmosphere is nearest to the surface of the earth?

• Mesosphere
• Thermosphere
• Troposphere
• Stratosphere
Correct Option: C  [ Troposphere ]

Remark:

Tajmahal is threatened mostly due to :

• Sulphur dioxide
• Carbon dioxide
• Carbon monooxide
• Water Vapour
Correct Option: A  [ Sulphur dioxide ]

Remark:

Plants prepare their food by:

• photosynthesis
• carbohydrolysis
• metabolic synthesis
• photorespiration
Correct Option: A  [ photosynthesis ]

Remark: