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. 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.
3. 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.
4. Heart attack occurs due to
____:
[A] Impairment of hearts working due to unknown reasons
[B] Bacterial attack on the heart
[C] Lack of supply of blood to the heart itself
[D] Stopping of heart beat
Show Answer
Correct Answer: C [Lack of supply of blood to the heart itself]
Notes:
A heart attack occurs when blood flow to a part of your heart is blocked for a long enough time that part of the heart muscle is damaged or dies. The medical term for this is myocardial infarction. Most heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. If the blood flow is blocked, the heart is starved of oxygen and heart cells die.
5. 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.
6. The part of brain which controls emotional reactions in our body is ____:
[A] Hypothalamus
[B] Meninges
[C] Cerebrum
[D] Thalamus
Show Answer
Correct Answer: A [Hypothalamus]
Notes:
The brain’s limbic system controls emotional expression through the hypothalamus, which has control over the body’s emotional responses systems. The hypothalamus is responsible for regulating hunger, thirst, response to pain, levels of pleasure, sexual satisfaction, anger and aggressive behavior, etc. It also regulates pulse, blood pressure, breathing, and arousal in response to emotional circumstances.
7. Which one of the following endocrine gland is situated in the neck?
[A] Pituitary
[B] Thyroid
[C] Pancreas
[D] Adrenals
Show Answer
Correct Answer: B [Thyroid]
Notes:
The thyroid gland is one of the largest endocrine glands in the human body which is found in the neck. It controls how quickly the body uses energy, makes proteins, and controls how sensitive the body is to other hormones.
8. In the grass lands, trees do not replace the grasses as a part of an ecological succession because of ____:
[A] Limited sun light and paucity of nutrients
[B] Insect and fungi
[C] Water limits and fire
[D] None of the above
Show Answer
Correct Answer: C [Water limits and fire]
Notes:
Ecological succession is unidirectional progressive process of development in an ecosystem or biome. Grass ecosystems are an early stage of succession in regions where the mature ecosystems are forests. However, grass ecosystems are climax ecosystems in grassland regions, where there is not enough rainfall to support a forest. Due to limiting factors such as water scarcity and forest fire, a grassland ecosystem changes to a desert ecosystem. The ecological succession of grassland is desert.
9. 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.
10. The strongest muscle (based on its weight) of the body is the masseter muscle and is located in the ___:
[A] Hand
[B] Jaw
[C] Thigh
[D] Chest
Show Answer
Correct Answer: B [Jaw]
Notes:
The masseter is located in the jaw and is one of the muscles of mastication or chewing. ? The bite strength of an average man is between 117 to 265 pounds. ? This ability to exert a force on an external object is an example of absolute strength.
