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 is correct about effective nuclear charge experienced by the orbital?
[A] it increases with increase of azimuthal quantum number
[B] it increases with increase of magnetic quantum number
[C] it decreases with increase of azimuthal quantum number
[D] It is same everywhere
Show Answer
Correct Answer: C [it decreases with increase of azimuthal quantum number]
Notes:
Because of the screening effect, the net positive charge experienced by the electron from the nucleus is lowered and is known as effective nuclear charge. Effective nuclear charge experienced by the orbital decreases with increase of azimuthal quantum number(l).
2. Which of the following structures are present in the throat to prevent the air passage from collapsing?
[A] Rings of cartilage
[B] Rings of muscle
[C] Rings of bone
[D] Rings of connective tissue
Show Answer
Correct Answer: A [Rings of cartilage]
Notes:
Rings of cartilage are present in the throat, specifically in the trachea or windpipe, to ensure that the air passage does not collapse. These semi-circular rings provide the necessary structural support to keep the airway open regardless of pressure changes that occur during breathing. This is very important for maintaining a clear, open path for air to flow into our lungs for respiration.
3. What is the ultimate product of Glycolysis?
[A] Pyruvic acid
[B] Carbon dioxide
[C] Glucose
[D] Ethyl alcohol
Show Answer
Correct Answer: A [Pyruvic acid]
Notes:
Glycolysis, part of cellular respiration, is a series of reactions that constitute the first phase of most carbohydrate catabolism, catabolism meaning the breaking down of larger molecules into smaller ones. Glycolysis breaks down glucose and forms pyruvate with the production of two molecules of ATP. The entire process from conversion of glucose to pyruvate is anaerobic that is it does not take place in presence of oxygen.
4. What does Insulin do?
[A] Increases blood sugar
[B] Decreases blood sugar
[C] Constricts blood vessels
[D] Stimulates lactation
Show Answer
Correct Answer: B [Decreases blood sugar]
Notes:
Insulin is central to regulating carbohydrate and fat metabolism in the body. It stops the use of fat as an energy source by inhibiting the release of glucagon. It removes excess glucose from the blood, which otherwise would be toxic. Insulin helps blood sugar enter the body’s cells so it can be used for energy. Insulin also signals the liver to store blood sugar for later use. Blood sugar enters cells, and levels in the bloodstream decrease, signaling insulin to decrease too.
5. 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.
6. 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.
7. Seed dormancy is regulated by ____:
[A] Abscisic acid
[B] Indole acetic acid
[C] Ethylene
[D] Gibberellic acid
Show Answer
Correct Answer: A [Abscisic acid]
Notes:
The transition from dormancy to germination in seeds is a key physiological process during the lifecycle of plants. Abscisic acid (ABA) is the sole plant hormone known to maintain seed dormancy. It acts through a gene expression network involving the transcription factor Abscisic Acid Insensitive 3 (ABI3).
8. In which one of the following is swim bladder absent?
[A] Cartilaginous fish
[B] Silverfish
[C] Cuttlefish
[D] Bony fish
Show Answer
Correct Answer: A [Cartilaginous fish]
Notes:
The swim bladder is an internal gas-filled organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth without having to waste energy in swimming. The cartilaginous fish (e.g. sharks and rays) split from the other fishes about 420 million years ago and lack both lungs and swim bladders, suggesting that these structures evolved after that split.
9. 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.
10. A molecule in plants comparable to haemoglobin in animals is ____:
[A] Carotene
[B] Chlorophyll
[C] Cellulose
[D] Cytochrome
Show Answer
Correct Answer: B [Chlorophyll]
Notes:
Haemoglobin is the iron-containing oxygen transporting metalloprotein in the red blood cells of all vertebrates. Similarly, Cytochromes are, in general, membrane-bound haemo-proteins containing heme groups and are primarily responsible for the generation of ATP via electron transport.