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 antiseptic compounds is present in Dettol?
[A] Iodine
[B] Cresol
[C] Chloroxylenol
[D] Biothional
Show Answer
Correct Answer: C [ Chloroxylenol ]
Notes:
Chloroxylenol, also known as para-chloro-meta-xylenol, is an antiseptic and disinfectant which is used for skin disinfection and cleaning surgical instruments. It is also used within a number of household disinfectants and wound cleaners.
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. Which of the following protein is found in nails?
[A] Keratin
[B] Histone
[C] Actin
[D] Elastin
Show Answer
Correct Answer: A [Keratin]
Notes:
Keratin is a family of fibrous structural proteins that is the key structural component of hair and nails. It is also the key structural material making up the outer layer of human skin. Besides, it provides the necessary strength and toughness for masticatory organs, such as the tongue.
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. 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).
7. The pigment that gives human skin, hair and eyes their colour is called ____:
[A] Quinacridone
[B] Alizarin
[C] Melanin
[D] Phthalocyanine
Show Answer
Correct Answer: C [Melanin ]
Notes:
The pigment that gives human skin, hair, and eyes their color. Dark-skinned people have more melanin in their skin than light-skinned people have. Melanin is produced by cells called melanocytes. Everyone has the same number of melanocytes, but some people make more melanin than others.
8. The colour change in the Chameleon is due to the presence of ____:
[A] Chromatophore
[B] Haemoglobin
[C] Chlorophyll
[D] Pneumatophore
Show Answer
Correct Answer: A [Chromatophore]
Notes:
Chameleons have specialized cells, chromatophores, which contain pigments in their cytoplasm, in three layers below their transparent outer skin. Dispersion of the pigment granules in the chromatophores sets the intensity of each color. Chromatophores contain pigments and reflect light, which are responsible for creating coloration. In chameleons, there are four types of chromatophores: xanthophores, erythrophores, iridiophores, and melanophores (Cooper and Greenberg, 1992).
9. Which of the following acids is synthesized in human stomach?
[A] Hydrochloric acid
[B] Sulphuric acid
[C] Nitric acid
[D] Phosphoric acid
Show Answer
Correct Answer: A [Hydrochloric acid]
Notes:
A typical adult human stomach will secrete about 1.5 liters of gastric acid daily. The best-known component of gastric juice is hydrochloric acid, the secretory product of the parietal, or oxyntic cell. It is known that the capacity of the stomach to secrete HCl is almost linearly related to parietal cell numbers.
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.
