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 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.
2. What percentage of carbon is present in steel?
[A] 0.0 to 2.5
[B] 2.5 to 5.0
[C] 5.0 to 7.5
[D] 7.5 to 10.0
Show Answer
Correct Answer: A [0.0 to 2.5 ]
Notes:
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2. 1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
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. ____ is the cell organelle, in which the biochemical processes of respiration and energy production occur:
[A] Ribosomes
[B] Mitochondria
[C] Nucleus
[D] Chloroplast
Show Answer
Correct Answer: B [Mitochondria]
Notes:
Mitochondria is an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It is for this reason that mitochondria are often referred to as the powerhouses of the cell mitochondria also play a key role in the ageing process as well as in the onset of degenerative disease.
5. What is the basis of classifying various plant tissues as meristematic tissue and permanent tissue?
[A] Size
[B] Dividing capacity
[C] Location
[D] None of the above
Show Answer
Correct Answer: B [Dividing capacity]
Notes:
Based on the dividing capacity of the tissues, various plant tissues can be classified as growing or meristematic tissue and permanent tissue. Meristem is a type of tissue system in plants, composed of a mass of undifferentiated cells and their primary function is to take part in the growth of plants. Permanent tissues are differentiated tissues doing specific functions such as conduction, providing mechanical support or carrying out photosynthesis etc.
6. Which of the following is the smallest bird?
[A] Parrot
[B] Pigeon
[C] Hummingbird
[D] House sparrow
Show Answer
Correct Answer: C [Hummingbird ]
Notes:
Humming birds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm (3–5 in) range. Indeed, the smallest extinct bird species is a humming bird, the 5-cm Bee Humming bird. These birds being the smallest are, capable of flying both in forward and back direction.
7. Cuscuta is a ____:
[A] Complete stem parasite
[B] Partial root parasite
[C] Partial stem parasite
[D] Complete root parasite
Show Answer
Correct Answer: A [Complete stem parasite]
Notes:
Cuscuta (Dodder) is a genus of about 100-170 species of yellow, orange or red (rarely green) parasitic plants. Dodders are supremely adapted for a life of plunder and pillage. Reduced in form to scrambling and twining threads, they appear to be completely leafless, although closer inspection reveals tiny scale leaves pressed close to the stems. So, it is a stem parasite.
8. The duration 19-21 days refers to ___:
[A] The period of menstrual cycle soon after menstruation, during which fertilisation is most likely to occur
[B] Incubation period of hens egg
[C] Average life-span of a red blood cell in humans
[D] Period of completion of one schizogony cycle of malarial parasite inside a red blood cell
Show Answer
Correct Answer: A [The period of menstrual cycle soon after menstruation, during which fertilisation is most likely to occur]
Notes:
In menstrual cycle 19-21 days stands for the fertilizing period also called danger period. After ovulation on 14th day chances of contraption are at their highest with well developed endometrium for implantation. This is the time in the menstrual cycle when progesterone should be at its peak for the month and when estrogen should be at the height of its luteal plateau.
9. Blood pressure is measured by ____:
[A] Hydrometer
[B] Thermometer
[C] Sphygmanometer
[D] Barometer
Show Answer
Correct Answer: C [Sphygmanometer]
Notes:
Sphygmomanometer an instrument for measuring blood pressure. It typically consists of an inflatable rubber cuff which is applied to the arm and connected to a column of mercury next to a graduated scale, enabling the determination of systolic and diastolic blood pressure by increasing and gradually releasing the pressure in the cuff. The sphygmomanometer was invented by Samuel Siegfried Karl Ritter von Basch in 1881.
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.