General Science Questions (MCQs) for Competitive Examinations
General Science Multiple choice questions for GK paper in SSC, NDA, CDS, UPSC, UPPSC and State PSC Examinations. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
1. The exceptionally low melting point of mercury can be explained on the basis of which of the following explanations?
1. Mercury has completely filled-up atomic orbitals
2. In mercury, the binding energy of outer electrons (towards nucleus) is highest and no electron is available to participate in metallic bond formation
Choose the correct option from the codes given below:
[A] Only 1 is correct
[B] Only 2 is correct
[C] Both 1 & 2 are correct
[D] Neither 1 nor 2 is correct
Show Answer
Correct Answer: C [ Both 1 & 2 are correct]
Notes:
Mercury belongs to the zinc group of elements in the periodic table, which comprises zinc, cadmium and mercury. They all have completely filled-up atomic orbitals. It becomes difficult to knock out these electron(s) from their orbitals and form metallic bonds. With its filled shell electron configuration it is very reluctant to form bonds even with other mercury atoms.
2. The suicidal bags of the cell are
____:
[A] Ribosomes
[B] Lysosomes
[C] Phagosomes
[D] Dictyosomes
Show Answer
Correct Answer: B [Lysosomes]
Notes:
Lysosomes are called the suicide bags of the cells they contain digestive enzymes, and break down food, cellular debris and foreign invaders like bacteria. When the cell is injured beyond repair, or becomes old, the lysosome digests the cell. So, it is called “suicide bag of the cell.”
3. Which one of the following endocrine gland is situated in the neck?
[A] Pituitary
[B] Thyroid
[C] Pancreas
[D] Adrenals
Show Answer
Correct Answer: B [Thyroid]
Notes:
The thyroid gland is one of the largest endocrine glands in the human body which is found in the neck. It controls how quickly the body uses energy, makes proteins, and controls how sensitive the body is to other hormones.
4. An eardrum is absent in ____:
[A] Snakes
[B] Toads
[C] Turtles
[D] Tuatara
Show Answer
Correct Answer: A [Snakes]
Notes:
The ear has three main parts: the outer, middle and inner ear. The outer ear consists of the pinna and the auditory canal. The middle ear is filled with air and contains three tiny bones called ossicles – the anvil, hammer and stirrup. The inner ear contains the semicircular canals and the cochlea. Eardrum is the membrane of middle ear. Snakes have fully developed inner ear structures but no eardrum.
5. The biological process in which both aerobes and anaerobes degrade organic matter is ____:
[A] Digesting
[B] Composting
[C] Manuring
[D] Nutrifying
Show Answer
Correct Answer: B [Composting]
Notes:
Composting is the depomposition of plant remains and other once-living materials to make an earthy, dark, crumbly substance that is excellent for enriching soil. It is the chief way to recycle wastes.
6. Which of the following diseases has been eradicated worldwide?
[A] Smallpox
[B] Plague
[C] Chickenpox
[D] Dracunculiasis
Show Answer
Correct Answer: A [Smallpox]
Notes:
Smallpox was one of the world’s most devastating diseases known to humanity. The last known natural case was in Somalia in 1977. It was declared eradicated in 1980 following a global immunization campaign led by the World Health Organization. Smallpox is caused by infection with the variola virus.
7. When we touch leaves of “Touch me not plant”, they close, these movements are called ____:
[A] Seismonastic movements
[B] Photonastic movements
[C] Nyctinastic movements
[D] Chemonastic movements
Show Answer
Correct Answer: A [Seismonastic movements]
Notes:
These types of mechanism have been termed seismonastic movements. The movement occurs when specific regions of cells lose turgor pressure, which is the force that is applied onto the cell wall by water within the cell vacuoles and other cell contents.
8. Which of the following statement is incorrect?
[A] Each sperm is a single cell
[B] Oviparous animal does not give birth to young ones
[C] External fertilisation takes place in frog
[D] Fertilisation is necessary even in asexual reproduction
Show Answer
Correct Answer: D [Fertilisation is necessary even in asexual reproduction]
Notes:
While fertilization is necessary for organisms that reproduce sexually, individuals that reproduce asexually?do so without the need for fertilization. These organisms produce genetically identical copies of themselves through?binary fission, budding, fragmentation, parthenogenesis, or other forms of asexual reproduction.
9. Solitary cymose inflorescence is observed in ____:
[A] Rose
[B] Tuberose
[C] Chinarose
[D] Gardenia
Show Answer
Correct Answer: D [Gardenia]
Notes:
Solitary cymose inflorescence refers to a determinate inflorescence composed of a single flower. Examples include poppy, gardenia (ornamental plant), tulip, etc. Flowers are said to be solitary when the plant bears only one, or when single flowers appear on the ends of lateral branches that are remote from one another.
10. If a healthy freshwater fish is placed in salt water, what will be the expected consequence?
[A] The fish becomes dehydrated and dies
[B] The fish becomes bloated and dies
[C] The fish suffers from fungal or bacterial disease and dies
[D] There is no observable effect on the fish provided there is sufficient food
Show Answer
Correct Answer: A [The fish becomes dehydrated and dies]
Notes:
When freshwater fish is placed in salt water, the water molecules contained in the fish’s body would pass through the cell membranes of the fish, causing the fish to lose water by osmosis. This sudden change in the molecular makeup of the fish would cause the fish to undergo severe dehydration followed by death.
