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 elements is present in heavy water?
[A] Heavy Oxygen
[B] Heavy Hydrogen
[C] Heavy Chlorine
[D] Heavy Nitrogen
Show Answer
Correct Answer: B [Heavy Hydrogen ]
Notes:
Heavy water is water that contains heavy hydrogen or deuterium. Deuterium differs from the hydrogen usually found in water, protium, in that each atom of deuterium contains a proton and a neutron. Heavy water may be deuterium oxide, D2O or it may be deuterium protium oxide, DHO.
2. Membrane lipids of chillsensitive plants contain ____:
[A] Low proportion of saturated fatty acids
[B] Equal proportion of saturated and unsaturated fatty acids
[C] Low proportion of unsaturated fatty acids
[D] High proportion of unsaturated fatty acids
Show Answer
Correct Answer: D [High proportion of unsaturated fatty acids]
Notes:
The membranes of chill sensitive plants have about a 2 :1 ratio of unsaturated to saturated fatty acids. It has been seen that the proportion of unsaturated membrane fatty acids increases and the critical temperature decreases so that chill-sensitive plants are more acclimitized to low temperatures.
3. Which one of the following is commonly known as Pond Silk?
[A] Yeast
[B] Rhizopus
[C] Ulothrix
[D] Spirogyra
Show Answer
Correct Answer: D [Spirogyra]
Notes:
Pond silk is the common name of Spirogyra (algae) because it is very slimy in shape. It is also known as pond silk, water silk, pond scum or mermaid’s trees because of its bright green silky appearance. Its filaments shine like silk due to the presence of mucilage and spiral shaped chloroplast.
4. 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.
5. Consider the following statements about how plants absorb nitrogen:
- Plants absorb nitrogen in the form of inorganic nitrates or nitrites.
- Plants take in nitrogen in the form of organic compounds.
- Nitrogen is directly taken up by the plants from the atmosphere.
Which of the above statements is / are correct?
[A] Only 1 and 2
[B] Only 1 and 3
[C] Only 2 and 3
[D] All of these
Show Answer
Correct Answer: A [Only 1 and 2]
Notes:
Plants obtain nitrogen through their roots. In the soil, nitrifying bacteria change ammonia into nitrite (NO2 –) and then into nitrate (NO3 –), this process is known as nitrification. Furthermore, plants also absorb nitrogen in an organic form. Several organic compounds (compounds containing carbon) constitute the organic fraction of nitrogen in the soil. The organic matter in the soil exists as decomposing plant and animal residues, relatively stable decomposition-resistant compounds, and humus. The abundance of various forms of nitrogen can be altered by plant roots through the change in pH and secretion of organic compounds or oxygen.
6. The edible part of an onion is ____:
[A] Fleshy leaves
[B] Aerial stem
[C] Modified root
[D] Aerial flower
Show Answer
Correct Answer: A [Fleshy leaves]
Notes:
The edible portion in an onion is swollen leaves with a bit of stem. They are bulbs which, like garlic and leeks, are modified stems in which the primary storage tissue is expanded leaf bases. They come in white, yellow, and red varieties. The swollen leaves have sugar as stored food in them.
7. Osteocytes are found in ____:
[A] Blood
[B] Bone
[C] Lymph
[D] Cartilage
Show Answer
Correct Answer: B [Bone]
Notes:
An osteocyte, a star shaped cell, is the most commonly found cell in mature bone, and can live as long as the organism itself. Osteocytes are networked to each other via long cytoplasmic extensions that occupy tiny canals called canaliculi, which are used for exchange of nutrients and waste through gap junctions. The space that an osteocyte occupies is called a lacuna.
8. Preserved traces of living organisms retained in the form of impressions of the body parts in the soil are called ____:
[A] Specimen
[B] Phylogeny
[C] Fossils
[D] Antique
Show Answer
Correct Answer: C [Fossils]
Notes:
A fossil is the naturally preserved remains or traces of organisms that lived in the geologic past. There are two main types of fossils; body and trace. Body fossils include the remains of organisms that were once living, and trace fossils are the signs that organisms were present (i.e. footprints, tracks, trails, and burrows).
9. The part of the stem where a leaf arises is known as ___:
[A] Carpel
[B] Bud
[C] Node
[D] Tuber
Show Answer
Correct Answer: C [Node]
Notes:
The leaves arise in the regions of the plant known as the plant nodes and are therefore the point of attachment of the leaves. The region of the plant between two nodes is known as the internode. The angle between the upper surface of the leaf and the stem from which it arises is known as the axil.
10. People with Downs syndrome invariably affected by _____:
[A] Alzheimers disease
[B] Huntingtons disease
[C] Brain haemorrhage
[D] Meningitis
Show Answer
Correct Answer: A [Alzheimers disease]
Notes:
The best-known and most common chromosome abnormality in humans is Down’s syndrome, (Trisomy of 21st pair of chromosome). Down’s syndrome individuals also almost invariably develop Alzheimer’s disease, a form of dementia that is fairly common among the elderly people. People with Down’s syndrome develop this disease in their fourth or fifth decade of life, much sooner than other people. These people are also characterized by presence of webbed neck, Plamers crease, very broad forehead, round face and forked tongue.
