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. Which of the following are the limitations of Bohr’s model of atom?
[A] it cannot explain spectrum of atoms containing more than one electron
[B] it cannot explain the Zeeman effect
[C] it cannot explain the Stark effect
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Bohr’s model of atom cannot explain spectrum of atoms containing more than one electron. Also, it cannot explain the Zeeman effect i.e. splitting of spectral line in presence of magnetic field. It also fails to explain Stark effect i.e. splitting of spectral line in presence of electric field.
3. Among the given nutrients, milk is a poor source of which of the following?
[A] Carbohydrate
[B] Calcium
[C] Protein
[D] Vitamin C
Show Answer
Correct Answer: D [Vitamin C]
Notes:
Milk is a poor source of ascorbic acid (Vitamin C). It contains about 1 mg ascorbate per 100 g. Even the little Vitamin C is usually destroyed when the milk is heat treated. Milk as a complete food contains most of the esential nutrients except are vitamin C and iron.
4. Typhoid fever is caused by ____:
[A] Virus
[B] Bacteria
[C] Fungus
[D] Allergy
Show Answer
Correct Answer: B [Bacteria]
Notes:
Typhoid fever, also known as typhoid, is a common water borne worldwide bacterial disease, transmitted by the ingestion of food or water contaminated with the feces of an infected person, which contain the bacterium Salmonella Typhi.
5. Wilting of plants occurs due to excessive ____:
[A] Respiration
[B] Glutation
[C] Absorption
[D] Transpiration
Show Answer
Correct Answer: D [Transpiration]
Notes:
Plant wilting occurs after excessive loss of water by transpiration and lesser absorption. i.e. rate of transpiration exceeds rate of water absorption. On a hot day, plants transpire heavily and cannot absorb water speedily to keep pace with transpiration loss, even when there is enough water.
6. Which of the following processes are associated with plants during dark period?
[A] Respiration and transpiration
[B] Transpiration and conduction
[C] Photosynthesis and respiration
[D] Conduction and respiration
Show Answer
Correct Answer: D [Conduction and respiration]
Notes:
Conduction is the process by which vital nutrients are transported to the different parts of a plant. This process is independent of the light factor. Respiration process in plants is the intake of carbon-dioxide and exhales oxygen during the day as the plants gets energy through the photosynthesis process in which the carbon-dioxide is converted into sugars using the sun light energy, as this process uses carbon-dioxide and water, the resulting gas oxygen is given out as a waste product. During the night, as the photosynthesis process does not take place it exhales the carbon-dioxide itself.
7. The connective tissue that connects a muscle to a bone is _____:
[A] Cartilage
[B] Ligament
[C] Interstitial fluid
[D] Tendon
Show Answer
Correct Answer: D [Tendon]
Notes:
A tendon or sinew is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments; both are made of collagen. Ligaments join one bone to another bone, while tendons connect muscle to bone.
8. Commonest mammal is ____:
[A] Elephant
[B] Lion
[C] Human
[D] Panther
Show Answer
Correct Answer: C [Human]
Notes:
Humans are likely the most numerous species of mammal on Earth at the moment.
9. The hydrophilic nature of DNA is due to the presence of ____:
[A] A number of hydrogen bonds
[B] Phosphate group
[C] Thymine base
[D] Deoxyribose sugar
Show Answer
Correct Answer: A [A number of hydrogen bonds]
Notes:
The phosphate groups on DNA are ionic and charged. Each phosphate group on the DNA backbone has one unit of negative charge (-1). Charged molecules attract water and are hydrophilic. DNA has two hydrophilic polar external backbones made of sugars and phosphate groups joined by ester bonds. Therefore, DNA as nucleic acid is characterized by presence of phosphodiester bond.
10. ____ is the branch of zoology concerned with the study of amphibians:
[A] Herpetology
[B] Ethology
[C] Mammology
[D] Morphology
Show Answer
Correct Answer: A [Herpetology]
Notes:
Herpetology is the branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians (gymnophiona)) and reptiles (including snakes, lizards, amphisbaena, turtles, terrapins, tortoises, crocodilians, and the tuataras). It is the study of ectothermic (coldblooded) tetrapods.
