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 651–660 of 1113 questions
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RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q651. Consider the following statements about recombinant DNA (rDNA) technology: I. It involves cutting DNA from two different sources and joining them together. II. A host organism, typically a bacterium, is used to multiply the recombinant DNA. III. It completely avoids the use of vectors. IV. Stanley Cohen and Herbert Boyer produced the first recombinant DNA molecule. Which of the above statement(s) is/are correct?
Explanation
Recombinant DNA technology involves combining DNA fragments from different sources to create a new genetic sequence. A host organism, such as E. coli, is essential for cloning and multiplying this DNA. The first successful recombinant DNA was created by Cohen and Boyer.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q652. Consider the following statements regarding genetic engineering: Statement I: Genetic engineering allows for the transfer of genes across different biological species. Statement II: Natural sexual reproduction strictly restricts gene transfer to members of the same or closely related species. Which of the following represents the correct option?
Explanation
Genetic engineering breaks biological barriers by allowing the transfer of specific genes between entirely different species, such as moving a bacterial gene into a plant. In contrast, natural sexual reproduction is generally restricted by biological compatibility, occurring only between members of the same species or very closely related ones. This fundamental difference enables biotechnology to create organisms with traits that could never arise through traditional breeding.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q653. The first recombinant DNA molecule was created by linking an antibiotic resistance gene to a native plasmid of which bacterium?
Explanation
The first recombinant DNA molecule was constructed in 1972 by Stanley Cohen and Herbert Boyer. They successfully linked a gene encoding antibiotic resistance to a native plasmid of the bacterium Salmonella typhimurium. This pioneering experiment demonstrated that genetic material could be manipulated and functionalized in a foreign host, laying the foundation for the modern biotechnology industry.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q654. In recombinant DNA technology, the term transformation refers to:
Explanation
In the context of recombinant DNA technology, transformation refers to the process by which a host cell, typically a bacterium, takes up foreign DNA from its environment. This is a crucial step in gene cloning, as it allows the recombinant vector to enter the cell where it can replicate and express the inserted gene. Various methods, such as heat shock, are used to facilitate this uptake.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q655. Which of the following best describes a chimeric DNA?
Explanation
Chimeric DNA, often used synonymously with recombinant DNA, is a single DNA molecule that has been constructed in a laboratory using genetic material from two or more different biological sources or species. The name is derived from the Chimera of Greek mythology, a creature composed of parts from different animals. This molecular hybrid allows for the expression of specific foreign traits within a host organism.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q656. The primary goal of inserting a gene into a host organism during genetic engineering is to:
Explanation
The primary objective of inserting a specific gene into a host organism is to utilize the hosts cellular machinery to either create many identical copies of that gene or to synthesize large quantities of the protein the gene encodes. This process is essential for research, the manufacturing of therapeutic drugs like insulin, and the development of genetically modified organisms with enhanced agricultural or industrial properties.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q657. Identify the incorrect statement regarding the tools of genetic engineering.
Explanation
The enzyme used to synthesize complementary DNA from a messenger RNA template is reverse transcriptase, not RNA polymerase. RNA polymerase is actually responsible for synthesizing RNA from a DNA template during transcription. Other tools mentioned are correct: restriction enzymes act as molecular scissors, DNA ligase functions as molecular glue, and plasmids serve as essential vectors for carrying foreign genetic material into host cells.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q658. What role does calcium chloride play in the transformation process of bacteria in genetic engineering?
Explanation
During the transformation process, bacteria are treated with a high concentration of calcium chloride to increase their competence, or their ability to take up foreign DNA. The divalent calcium ions are thought to neutralize the negative charges on both the DNA and the bacterial cell membrane, making it easier for the recombinant DNA to pass through the cell wall during a subsequent heat shock.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q659. Restriction endonucleases are enzymes that:
Explanation
Restriction endonucleases are specialized enzymes that recognize specific, usually palindromic, sequences of nucleotides within a DNA molecule. Upon finding these recognition sites, the enzymes cleave the sugar-phosphate backbone at precise internal locations. This ability to cut DNA at predictable and specific sites is the cornerstone of recombinant DNA technology, enabling the isolation and manipulation of particular genes or DNA fragments.
RAS PrelimsScience and Technology · Genetics, Biotechnology and Nanotechnology
Q660. Match List-I with List-II regarding enzyme functions in biotechnology:
Enzyme
Function
A. Restriction Endonuclease
i. Forms phosphodiester bonds to join DNA fragments
B. DNA Ligase
ii. Cleaves DNA at specific palindromic sequences
C. DNA Polymerase
iii. Synthesizes complementary DNA from an RNA template
D. Reverse Transcriptase
iv. Synthesizes new DNA strands by adding nucleotides
Explanation
Different enzymes perform specific tasks in biotechnology. Restriction endonucleases cut DNA at palindromic sequences. DNA ligase joins DNA fragments by forming phosphodiester bonds. DNA polymerase is used to synthesize new DNA strands by adding nucleotides to a primer. Reverse transcriptase is essential for creating complementary DNA from an RNA template, which is a key step in cloning eukaryotic genes from messenger RNA.
Answer key for these questions
Q
Correct answer
651
(b) I, II and IV
652
(a) Both Statement I and Statement II are correct.
653
(a) Salmonella typhimurium
654
(b) The introduction of recombinant DNA into a host cell.
655
(d) Recombinant DNA formed from material of different species
656
(a) Production of gene copies or the encoded protein product
657
(c) RNA polymerase is the primary enzyme used to synthesize cDNA from mRNA.
658
(a) Facilitation of DNA entry by enhancing cell competence
659
(d) Cleavage of DNA at specific internal recognition sites
660
(a) A-ii, B-i, C-iv, D-iii
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.
