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 increases with increase of highly soluble impurities in water?
- Melting point
- Boiling point
- Surface tension
Select the correct option from codes given below:
[A] 1 & 2 Only
[B] 3 Only
[C] 2 & 3 Only
[D] 1, 2 & 3
Show Answer
Correct Answer: C [ 2 & 3 Only]
Notes:
The melting point of a pure substance is always higher than the melting point of that substance when a small amount of an impurity is present. Melting point decreases with increase of impurity in water. Increase in impurity increases the electrostatic attraction between ions and thus more energy is needed to break the bonds. The surface tension of water increases when highly soluble impurities are added to it.
3. Radioactive materials should be kept in the container made of:
[A] Iron
[B] Aluminum
[C] Steel
[D] Lead
Show Answer
Correct Answer: C [Steel]
Notes:
Radioactive materials are first encased in resin or concrete and sealed in steel drums. The drums are then packed into concrete casks and placed in concrete trenches up to 18 metres deep.
4. What is Blubber?
[A] A layer of thick fat
[B] A device to trap insects by some aquatic
[C] A milky secretion of rubber plant
[D] Fungal infection of rice plants
Show Answer
Correct Answer: A [A layer of thick fat]
Notes:
Blubber is a thick layer of vascularized adipose tissue found under the skin particularly whales inhabiting of Arctic ocean. It’s presence insulate their body from ice cold. The energy stored in blubber includes both proteins (mostly collagen) and fats (mostly lipids). Blubber covers the entire body of animals such as seals, whales, and walruses—except for their fins, flippers, and flukes. Whaling largely targeted the collection of blubber: whalers rendered it into oil in try pots, or later, in vats on factory ships. The oil could serve in the manufacture of soap, leather, and cosmetics. Whale oil was used in candles as wax, and in oil lamps as fuel.
5. Root cap is derived from
____:
[A] Dermatogen
[B] Calyptrogen
[C] Protoderm
[D] Histogen
Show Answer
Correct Answer: B [Calyptrogen]
Notes:
Calyptrogen is a layer of rapidly dividing cells at the tip of a plant root, from which the root cap is formed. It occurs in grasses and many other plants. The root cap is formed by several layers of cells that envelop the root tip externally. This covering of cells, of which the outermost ones are dead, envelops and protects the growing tip of root.
6. The wing of a bat and the wing of a bird are the examples of ____ limbs:
[A] Heterogeneous
[B] Homogenous
[C] Homologous
[D] Analogous
Show Answer
Correct Answer: D [Analogous]
Notes:
The wings of insects, bats and birds, that evolved independently in each lineage separately after diverging from an ancestor without wings, are examples of analogous organs. Analogous organs are the opposite of homologous organs, which have similar functions but different origins.
7. Which organ is the main digester and absorber of food?
[A] Colon
[B] Stomach
[C] Liver
[D] Small intestine
Show Answer
Correct Answer: D [Small intestine]
Notes:
The small intestine, the part of the gastrointestinal tract between the stomach and the large intestine, is the main digester and absorber of food. The small intestine has three distinct regions – the duodenum, jejunum, and ileum–that carry out the absorption of nutrients and minerals from food. It converts the food into a semi-solid mass.
8. To digest protein which of the enzyme is present in pancreatic juice?
[A] Pepsin
[B] Upes
[C] Trypsin
[D] Amaylase
Show Answer
Correct Answer: C [Trypsin]
Notes:
Trypsin is an enzyme that helps us digest protein. In the small intestine, trypsin breaks down proteins, continuing the process of digestion that began in the stomach. It may also be referred to as a proteolytic enzyme, or proteinase. Trypsin is produced by the pancreas in an inactive form called trypsinogen. The trypsinogen enters the small intestine through the common bile duct and is converted to active trypsin.
9. How the rate of absorption of water through roots can be increased?
[A] Keeping the plants under the fan
[B] Keeping the plants in the dim light
[C] Keeping the plants in the shade
[D] Covering the plants with a polythene bag
Show Answer
Correct Answer: A [Keeping the plants under the fan]
Notes:
When a plant is placed under the fan, the speed of air is increased which leads to high rate of transpiration through the stomata. The increase in the rate of transpiration increases the water absorption also. As by keeping the plants under the fan, the transpiration process is boosted. Therefore, more amount of water and other minerals are absorbed by the plant roots from the soil.
10. Which among the following has open circulatory system?
I. Cockroach
II. Human
III. Prawn
[A] I and II
[B] I and III
[C] II and III
[D] Only III
Show Answer
Correct Answer: B [I and III]
Notes:
Cockroach and prawns have open circulatory system in which the blood is not confined within blood vessels. The blood bathes the organs and tissues directly. Open circulatory systems pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood. The open circulatory system is common to molluscs and arthropods.