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. Which of the following is correct about effective nuclear charge experienced by the orbital?
[A] it increases with increase of azimuthal quantum number
[B] it increases with increase of magnetic quantum number
[C] it decreases with increase of azimuthal quantum number
[D] It is same everywhere
Show Answer
Correct Answer: C [it decreases with increase of azimuthal quantum number]
Notes:
Because of the screening effect, the net positive charge experienced by the electron from the nucleus is lowered and is known as effective nuclear charge. Effective nuclear charge experienced by the orbital decreases with increase of azimuthal quantum number(l).
2. Biofortification is a ____:
[A] Method of plant breeding for disease resistance
[B] Method of developing resistance to insect pests
[C] Method of breeding crops to increase their nutritional value
[D] Strategy to combat unwanted nutrients in plants
Show Answer
Correct Answer: C [Method of breeding crops to increase their nutritional value]
Notes:
Biofortification is the breeding crops to increase their nutritional value. This can be done either through conventional selective breeding or genetic engineering. Biofortification differs from ordinary fortification because it focuses on making plant foods more nutritious as the plants are growing, rather than having nutrients added to the foods when they are being processed.
3. Hydrochloric acid is secreted by the cells lining the
____:
[A] Stomach
[B] Ileum
[C] Oral cavity
[D] Colon
Show Answer
Correct Answer: A [Stomach]
Notes:
The chief cells of the stomach secrete enzymes for protein breakdown (inactive pepsinogen and rennin). Hydrochloric acid activates pepsinogen into the enzyme pepsin, which then helps digestion by breaking the bonds linking amino acids, a process known as proteolysis.
4. In winter, at the time of hibernation, Toads maintain breathing through ____:
[A] Lungs
[B] Skin
[C] Both by Skin and Lungs
[D] Buccal cavity
Show Answer
Correct Answer: B [Skin]
Notes:
During hibernation in winter, toads or frogs spend the time tucked away deep in the soil, in the mud underwater or hidden amidst foliage or rotting plants. Outside of times of hibernation, they usually take in oxygen via the air, employing their lungs. However, during hibernation, they receive their necessary oxygen through their permeable skin. This is referred to as cutaneous gas exchange.
5. Which one of the following features is absent in a virus?
[A] Presence of cell wall
[B] Reproduce within host cell
[C] Fully parasitic in nature
[D] Presence of either DNA or RNA
Show Answer
Correct Answer: A [Presence of cell wall]
Notes:
A virus has a simple structure. It has no internal cellular structure, no cell wall or cell membrane, just the protein coat that holds the string of nucleic acid. It is made only of a nucleic acid + a protein coat. A cell wall is a layer located outside the cell membrane found in plants, fungi, bacteria, algae, and archaea.
6. Which of the following cell organells are present only in plant cell?
[A] Lysosomes
[B] Plastids
[C] Mitochondria
[D] Cell membrane
Show Answer
Correct Answer: B [Plastids]
Notes:
The plastid is a major double-membrane organelle found in the cells of plants. Plastids are the site of manufacture and storage of important chemical compounds used by the cell. Plastids often contain pigments used in photosynthesis, and the types of pigments present can change or determine the cell’s colour.
7. 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.
8. Growing agricultural crops between rows of planted trees is known as ____:
[A] Jhum
[B] Agro forestry
[C] Social forestry
[D] Taungya system
Show Answer
Correct Answer: D [Taungya system]
Notes:
The Taungya system involves growing agricultural crops between rows of planted trees (sal, teak, etc). Along with jhum cultivation, it is one of the well-known systems of agro forestry programmes in practice in our country.
9. The colour change in the Chameleon is due to the presence of ____:
[A] Chromatophore
[B] Haemoglobin
[C] Chlorophyll
[D] Pneumatophore
Show Answer
Correct Answer: A [Chromatophore]
Notes:
Chameleons have specialized cells, chromatophores, which contain pigments in their cytoplasm, in three layers below their transparent outer skin. Dispersion of the pigment granules in the chromatophores sets the intensity of each color. Chromatophores contain pigments and reflect light, which are responsible for creating coloration. In chameleons, there are four types of chromatophores: xanthophores, erythrophores, iridiophores, and melanophores (Cooper and Greenberg, 1992).
10. Fat present below the skin surface in our body acts as a barrier against ____:
[A] Loss of heat from the body
[B] Loss of salt from the body
[C] Loss of essential body fluids
[D] Entry of harmful micro-organisms from the environment
Show Answer
Correct Answer: A [Loss of heat from the body]
Notes:
A layer of body fat acts as an insulator and traps heat. The subcutis is the deepest layer of skin. The subcutis, consisting of a network of collagen and fat cells, helps conserve the body’s heat and protects the body from injury by acting as a “shock absorber.
