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. Epidermal cells of which part of plant often secrete a waxy water resistant layer on their outer surface?
[A] Aerial parts only
[B] Roots only
[C] Both aerial parts and roots
[D] Neither aerial parts nor roots
Show Answer
Correct Answer: A [Aerial parts only]
Notes:
The major role of epidermis is to protect all the parts of the plant. Epidermal cells on the aerial parts of the plant often secrete a waxy, water-resistant layer on their outer surface. This aids in protection against loss of water, mechanical injury and invasion by parasitic fungi.
2. Filariasis is not transmitted by ____:
[A] Anopheles mosquito
[B] Aedes mosquito
[C] Culex mosquito
[D] Swamp mosquito
Show Answer
Correct Answer: D [Swamp mosquito]
Notes:
Most cases of filariasis are caused by the parasite known as Wuchereria bancrofti. A wide range of mosquitoes can transmit this parasite, depending on the geographic area. In Africa, the most common vector is Anopheles while in the Americas, it is Culex quinquefasciatus. Aedes and Mansonia transmits transmit the infection in the Pacific and in Asia. Thus, Culex, Aedes and Anopheles mosquitoes serve as vector for W. bancrofti in transmission of the disease. Aedes mosquito causes dengue fever. Anopheles mosquito causes malaria. Culex mosquito causes filaria. A wide range of mosquitoes can transmit the parasite, depending on the geographic area. In Africa, the most common vector is Anopheles and in the Americas, it is Culex quinquefasciatus. [This question was wrongly framed in exam as “filaria is caused by__:”. GKtoday has edited it to make it correct.]
3. Which of the following is not a multicellular organism?
[A] Fungi
[B] Hydra
[C] Spirogyra
[D] Paramecium
Show Answer
Correct Answer: D [Paramecium]
Notes:
Multicellular organisms are made up of more than one cell. The development of multicellular organisms is accompanied by cellular specialization and division of labor; cells become efficient in one process and are dependent upon other cells for the necessities of life. Paramecium is single-celled protists naturally found in aquatic habitats. Paramecium is the only genus in the family Parameciidae, which resides within the phylum Ciliophora.
4. 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.
5. The special modified epidermal cells surrounding stomatal pore are called ____:
[A] Accessory cells
[B] Epithelial cells
[C] Guard cells
[D] Subsidiary cells
Show Answer
Correct Answer: C [Guard cells]
Notes:
The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the opening. Guard cells are specialized cells in the epidermis of leaves, stems and other organs that are used to control gaseous exchange and rate of transpiration.
6. 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.
7. Which of the following is/are agent(s) of infection?
[A] Physical contact
[B] Water
[C] Vectors
[D] All of the above
Show Answer
Correct Answer: D [All of the above ]
Notes:
Infection is the invasion of an organism’s body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to the infectious agents and the toxins they produce. Infectious diseases can be spread from one person to another, for example through contact with bodily fluids, by aerosols (through coughing and sneezing), or via a vector, for example a mosquito.
8. The release of which of the following into ponds and wells helps in controlling mosquitoes?
[A] Snail
[B] Crab
[C] Dogfish
[D] Gambusia fish
Show Answer
Correct Answer: D [Gambusia fish]
Notes:
The Gambusia fish, also known as larvivorous stagnant water fish. It feeds on the larvae of mosquitoes. So it helps in controlling their population. It is also called ‘mosquito fish’ and is being used as a biological control measure. Hence, a check on malaria and other vector borne diseases like even dengue.
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. Element that is not found in blood is ___:
[A] Copper
[B] Iron
[C] Chromium
[D] Magnesium
Show Answer
Correct Answer: C [Chromium ]
Notes:
In the blood the key minerals are iron, copper, zinc, sodium, potassium, calcium and magnesium. Minerals constitute important part of blood plasma that constitutes almost 55% of blood. In the blood, iron is found in larger amounts than any other mineral.
