General Science MCQ Quiz - Objective Question with Answer for General Science - Download Free PDF

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General Science Question 1 Detailed Solution

Key Points

• Protein synthesis is the primary function of ribosomes in a cell.
• Ribosomes are complex molecular machines found within all living cells, serving as the site of biological protein synthesis (translation).
• They link amino acids together in the order specified by messenger RNA (mRNA) molecules.
• Ribosomes are composed of two subunits, the small subunit, which reads the RNA, and the large subunit, which joins amino acids to form a polypeptide chain.
• Protein synthesis is essential for cell growth, function, and replication.

Additional Information

• Ribosomes can be found floating freely within the cytoplasm or attached to the endoplasmic reticulum, forming rough ER.
• In eukaryotic cells, ribosomes are also found within mitochondria and chloroplasts.
• Ribosomes are made up of ribosomal RNA (rRNA) and proteins.
• The process of protein synthesis involves two main stages: transcription (in the nucleus) and translation (at the ribosome).
• During translation, tRNA molecules bring the appropriate amino acids to the ribosome based on the sequence of codons in the mRNA.

General Science Question 2:

1. the scattering of sunlight by air molecules
2. the presence of water vapour
3. the absorption of blue light due to the air
4. the scattering of white light

Answer (Detailed Solution Below)

General Science Question 2 Detailed Solution

Key Points

• The scattering of sunlight by air molecules is the primary reason for the sky's blue color.
• This phenomenon is known as Rayleigh scattering, which occurs when the molecules and small particles in the atmosphere scatter short-wavelength light, such as blue, more efficiently than longer wavelengths, like red.
• As a result, when we look up at the sky, we predominantly see scattered blue light.
• The effect is more pronounced when the sun is higher in the sky, leading to a vivid blue color.

Additional Information

• Rayleigh scattering is named after the British scientist Lord Rayleigh, who first described this phenomenon in the 19th century.
• In addition to making the sky appear blue, Rayleigh scattering also contributes to the red and orange hues seen during sunrise and sunset, as the light passes through a greater thickness of the Earth's atmosphere.
• The scattering of light by atmospheric particles is also responsible for other optical phenomena, such as the white appearance of clouds and the halo effect around the sun or moon.
• Understanding the principles of light scattering helps in various scientific fields, including meteorology, astronomy, and environmental science.

General Science Question 3:

1. electric conductance
2. magnetic flux
3. magnetic flux density
4. More than one of the above
5. None of the above

Answer (Detailed Solution Below)

General Science Question 3 Detailed Solution

The correct answer is magnetic flux.

Key Points

• Magnetic flux is a measurement of the total magnetic field which passes through a given area.
• Magnetic flux is the product of the average magnetic field times the perpendicular area that it penetrates.
• The SI unit of magnetic flux is Weber (Wb).

Important Points

• Conductance explains the ease with which electric current flows through a substance.
• Magnetic flux density is defined as the amount of magnetic flux in an area taken perpendicular to the magnetic flux's direction.
• Capacitance is the ability of a body to hold an electrical charge.

General Science Question 4:

1. Scattering
2. Reflection
3. Refraction
4. More than one of the above
5. None of the above

Answer (Detailed Solution Below)

General Science Question 4 Detailed Solution

The correct answer is Scattering.

Key Points

• When light passes from one medium to any other medium say air, a glass of water then a part of the light is absorbed by particles of the medium preceded by its subsequent radiation in a particular direction. This phenomenon is termed a scattering of light.
• Rayleigh's law of scattering :-
  • According to Rayleigh's law of scattering , the intensity of light of wavelength λ present in the scattered light is inversely proportional to the fourth power of λ, provided the size of the scattering particles is much smaller than λ . Mathematically,
  • \(I \propto \frac<\lambda^4 >\)

  

  ​ Additional Information

  • The molecules of air and other fine particles in the atmosphere have a size smaller than the wavelength of visible light .
  • These are more effective in scattering light of shorter wavelengths at the blue end than the light of longer wavelengths at the red end .
  • The r ed light has a wavelength of about 1.8 times greater than blue light .
  • Thus, when sunlight passes through the atmosphere, the fine particles in the air scatter the blue colour (shorter wavelengths) more strongly than red .
  • The scattered blue light enters our eyes .
  • The red colour of the sun at sunrise is due to the scattering of light .

  

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  General Science Question 5:

  When will you find the magnetic field stronger?
  1. When the field lines are not seen
  2. When field lines are crowded
  3. When the lines are together
  4. More than one of the above
  5. None of the above

  Answer (Detailed Solution Below)

  Option 2 : When field lines are crowded

  General Science Question 5 Detailed Solution

  

  The correct answer is "When the field lines are crowded". Key Points

  • The magnetic field is strongest near the poles of the magnet.
  • The strength of the magnetic field depends on how close the magnetic field lines are.
  • Magnetic field - It is an area around a magnetic material within which the force of magnetism acts.
  • The magnetic field arises when a charge is in motion.

  

  Additional Information

  • William Gilbert stated that the earth is a magnet.
  • Magnetic field never crosses each other.
  • Denser the field lines, the greater will be the strength of the field.
  • Magnetic field lines always make closed loops.
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  Top General Science MCQ Objective Questions

  General Science Question 6

  Ribosomes are sites for
  1. Protein synthesis
  2. Photosynthesis
  3. Fat synthesis
  4. Respiration

  Answer (Detailed Solution Below)

  Option 1 : Protein synthesis

  General Science Question 6 Detailed Solution

  The correct answer is Protein synthesis.

  

  Key Points

  • Ribosomes are membranous granular structures present in the cytoplasm.
  • They were first observed under an electron microscope as dense particles by George Palade in the year 1953.
  • Ribosomes are the site for ''protein synthesis'' so they are also called the ''protein factory'' of the cell.
  • There are two types of ribosomes
  1. Eukaryotic ribosomes - 80s - occurs in the cytoplasm of eukaryotic cell
  2. Prokaryotic ribosomes - 70s - occur in the cytoplasm as well as are associated with the cell membrane of prokaryotic cell.
  • The subunits of the ribosomes are:
    • 80s ribosomes - are made of 60s and 40s subunits.
    • 70s ribosomes - are made of 50s and 30s subunits.

    

    Important Points

    • Composition of the structure of ribosome:
    • They are composed of ribonucleic acid (RNA) and proteins

    Type	Composition
    70s	60% rRNA + 40% proteins
    80s	40% rRNA + 60% proteins

    
    

    

    Additional Information

    • Photosynthesis: It is the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. In this process, plant the chlorophyll, carbon dioxide, water, sunlight, and release oxygen.
    • Synthesis of Fatty acids occurs in the cytoplasm.

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    General Science Question 7

    What type of waves are light wave?
    1. Transverse wave
    2. Longitudinal wave
    3. Both A & B
    4. None

    Answer (Detailed Solution Below)

    Option 1 : Transverse wave

    General Science Question 7 Detailed Solution

    • Wave: The disturbance that transfers energy from one place to another is called a wave.

    There are mainly two types of waves :

    1. Transverse waves: The wave in which the movement of the particles is at right angles to the motion of the energy is called a transverse wave. Light is an example of a transverse wave.
    2. Longitudinal wave: The wave in which the movement of the particles is parallel to the motion of the energy is called a longitudinal wave. The sound wave is an example of a longitudinal wave.
    • Light-wave is a transverse wave because its components vibrate perpendicular to its direction of propagation. So option 1 is correct.

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    General Science Question 8

    Among the following statements which is/are correct? 1. Plants convert energy from sunlight into food stored as carbohydrates 2. Plants have chlorophyll 3. Plant cells do not have cell walls

    1. Only 1 is correct
    2. Only 1 and 2 are correct
    3. Only 1 and 3 are correct
    4. All are correct

    Answer (Detailed Solution Below)

    Option 2 : Only 1 and 2 are correct

    General Science Question 8 Detailed Solution

    • The leaves have a green pigment called chlorophyll.
    • It helps leaves to capture the energy of the sunlight.
    • This energy is used to synthesise (prepare) food from carbon dioxide and water. Since the synthesis of food occurs in the presence of sunlight, it is called photosynthesis.

    In the presence of sunlight Carbon dioxide + water → Carbohydrate + oxygen.

    • Some plants, green algae, and cyanobacteria can perform photosynthesis.
    • The process of photosynthesis is commonly written as

    6CO 2 + 6H 2 O + Sun-Light → C 6 H 12 O 6 + 6O 2

    Plant cells have a cell wall to protect them and make them rigid structure.

    1. Plants convert energy from sunlight into food stored as carbohydrate’s - Correct

    2. Plants have chlorophyll. - Correct

    3. Plant cells do not have cell walls. - Incorrect.

    

    Additional Information

    In the plant cells, there are different components and organelles for specific functions-

    

    • Cell Wall – It is a rigid layer composed of cellulose. It is the outermost layer of the cell, below this cell membrane is present. The primary function of the cell wall is to protect and provide structural support to the cell.
    • Cell Membrane – It is a semi-permeable membrane that helps in regulating and the substance for entry and exit inside and outside the cell.
    • Nucleus – It is a vital part of the cell as it contains all the information or DNA of the cell and their heredity information for growth and cell division.
    • Vacuole – Most of the part of the plant cell is occupied by the vacuole. It is surrounded by Tonoplast. The vital role of the vacuole is to provide support again the pressure of the cell wall.
    • Golgi apparatus – They act as a transport system in the cell, as they transport various molecules to a different part of the cell.
    • Ribosomes – They are the sites of protein synthesis, also termed as the protein factory of the cell.
    • Mitochondrion – They break the complex molecules and produce energy and hence called the powerhouse of the cell.
    • Lysosomes – They are termed suicidal bags as they hold the enzymes that are capable to digest the whole cell itself.