1113 RAS Prelims practice MCQs on science and technology are on this page, in 6 chapters. They cover the basics of everyday science, computers and information technology, defence and space technology in India, genetics, biotechnology and nanotechnology, science and technology policies and government programmes, and recent advances with Indian contributors and indigenisation. Each question has an answer and an explanation.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 741–750 of 1113 questions
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RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q741. Consider the following steps of plant tissue culture (micropropagation): A. Hardening and acclimatization of plantlets B. Inoculation of explant on culture medium C. Selection and sterilization of explant D. Callus formation and regeneration of shoots/roots Which of the following represents the correct sequence?
Explanation
In micropropagation the explant is first selected and sterilised, then placed on the culture medium, then callus forms and shoots and roots regenerate, and finally the plantlets are hardened. The order is C, B, D, A.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q742. The capacity of a single plant cell to regenerate into an entire adult plant is known as:
Explanation
The capacity of a single plant cell to grow into a whole plant is called totipotency. It is the basis of plant tissue culture.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q743. In plant tissue culture, an unorganized mass of actively dividing cells is called a:
Explanation
An unorganised mass of actively dividing cells in plant tissue culture is called a callus.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q744. Which nematode infects the roots of tobacco plants causing a great reduction in yield, which is countered by RNAi technology?
Explanation
Meloidogyne incognita is the root-knot nematode that infects tobacco roots and reduces the yield. RNA interference (RNAi) technology is used to protect plants from it.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q745. Genetic variations observed in plants regenerated from tissue culture are called:
Explanation
Genetic variations seen in plants regenerated from tissue culture are called somaclonal variations.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q746. To produce virus-free plants from a virus-infected plant via tissue culture, which specific part of the plant is used as an explant?
Explanation
To get virus-free plants, the meristem (apical or axillary) is used as the explant, because the cells of the meristem are free of virus.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q747. The fusion of isolated protoplasts from two different plant species to create a hybrid (like the Pomato) is an example of:
Explanation
Somatic hybridization is a technique where the cell walls of two different plant species are removed to create protoplasts, which are then fused together to form a hybrid cell. This allows for the combination of traits from species that cannot be crossed through sexual reproduction. A famous example is the Pomato, a hybrid produced by fusing protoplasts from potato and tomato.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q748. What is the role of polyethylene glycol (PEG) in agricultural biotechnology?
Explanation
Polyethylene glycol is a chemical agent used in agricultural biotechnology to facilitate the fusion of plant protoplasts during somatic hybridization. Because protoplasts are negatively charged, they naturally repel each other. Adding PEG acts as a molecular bridge that reduces this repulsion and alters the cell membrane properties, allowing the protoplasts from two different species to come into close contact and merge.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q749. Which of the following best describes the principle of RNA interference (RNAi)?
Explanation
RNA interference is a natural biological process where double-stranded RNA molecules inhibit gene expression or translation. When dsRNA enters a cell, it is processed into short fragments that guide a protein complex to a specific messenger RNA molecule. The complex then binds to and cleaves the mRNA, preventing it from being translated into a protein. This results in specific gene silencing.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q750. Match List-I with List-II regarding nanomaterials:
Nanomaterial
Characteristic
A. Graphene
i. Hollow spherical cages of 60 carbon atoms
B. Carbon Nanotubes (CNTs)
ii. Semiconductor nanocrystals with unique optical properties
C. Quantum dots
iii. Cylindrical carbon structures with exceptional tensile strength
D. Fullerenes (Buckyballs)
iv. A single layer of carbon atoms arranged in a 2D hexagonal lattice
Explanation
Nanomaterials come in various structural forms. Graphene is a single, two-dimensional layer of carbon atoms in a hexagonal lattice. Carbon Nanotubes are cylindrical structures with immense strength. Quantum dots are tiny semiconductor crystals with unique optical properties, such as size-dependent light emission. Fullerenes are hollow spherical molecules composed of sixty carbon atoms arranged in a pattern resembling a soccer ball.
Answer key for these questions
Q
Correct answer
741
(a) C, B, D, A
742
(b) Totipotency
743
(a) Callus
744
(c) Meloidogyne incognita
745
(b) Somaclonal variations
746
(d) Meristem (apical or axillary)
747
(a) Somatic hybridization
748
(c) It induces the fusion of plant protoplasts.
749
(a) Gene silencing via complementary double- stranded RNA
750
(a) A-iv, B-iii, C-ii, D-i
Key facts from Science and Technology
The RPSC paper is General Knowledge and General Science, so science questions come with a strong dose of applied and recent topics.
Everyday science questions test the laws and terms of physics, chemistry and biology through examples.
Defence and space questions pair a missile, satellite or mission with its year and organisation.
Policy questions ask for the year, the body and the aim of schemes like STIP, the National Quantum Mission and BioE3.
Health, environment and agriculture are on a separate page, with their own chapters.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Science and Technology?
This page has 1113 practice MCQs on Science and Technology. Each has the correct answer, and most have an explanation.
Which chapters does the science and technology set cover?
Six chapters: basics of everyday science; computers, information and communication technology; defence and space technology in India; genetics, biotechnology and nanotechnology; science and technology policies and government programmes; and recent advances, Indian contributors and indigenisation.
Is science and technology part of the RAS Prelims syllabus?
Yes. The RPSC paper is called General Knowledge and General Science, and its syllabus lists science and technology topics along with environment, health, agriculture and government programmes, so questions can come from any of these areas.
How should I prepare science for RAS Prelims?
Revise the concepts by examples, then learn the missions, schemes and scientists with their year and organisation. Attempt each chapter, read the explanations and keep a list of the facts you missed.
