Q141. Who is credited with the first discovery and naming of the "cell" in 1665?
Science and Technology: RAS Prelims MCQs
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 141–150 of 1113 questions
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Q142. Which of the following is not a postulate of the classical Cell Theory?
Explanation
Classical cell theory says that all organisms are made of cells, the cell is the basic unit of life and all cells come from pre-existing cells. It does not say that all cells have a true nucleus, since bacterial cells have none, so D is not a postulate.
Q143. The primary distinguishing feature of a prokaryotic cell compared to a eukaryotic cell is the absence of:
Explanation
The fundamental difference between prokaryotic and eukaryotic cells is the organization of their genetic material. Eukaryotic cells have a distinct, membrane-bound nucleus that houses their DNA. In contrast, prokaryotic cells lack this structure; their genetic material is found in a region called the nucleoid, which is not separated from the rest of the cytoplasm by a protective membrane or envelope.
Q144. Which of the following structures is found in plant cells but strictly absent in animal cells?
Explanation
While both plant and animal cells share many organelles like mitochondria and the nucleus, plant cells have a rigid outer layer called the cell wall. Composed mainly of cellulose, this structure provides mechanical support and protection, helping the plant maintain its shape and withstand osmotic pressure. Animal cells lack a cell wall, possessing only a flexible plasma membrane as their outer boundary.
Q145. Mitochondria are often referred to as the "powerhouses" of the cell because they:
Explanation
Mitochondria are specialized organelles found in most eukaryotic cells and are responsible for aerobic cellular respiration. They convert the chemical energy from nutrients, such as glucose, into a form that the cell can easily use, known as adenosine triphosphate or ATP. This energy production is vital for all cellular activities, earning mitochondria the nickname "the powerhouses of the cell" in biology.
Q146. Consider the following cellular organelles and their functions:
I. Lysosomes - Intracellular digestion (suicide bags)
II. Ribosomes - Protein synthesis
III. Chloroplasts - Lipid synthesis
IV. Vacuoles - Storage of substances
Which of the above pair(s) is/are correctly matched?
I. Lysosomes - Intracellular digestion (suicide bags)
II. Ribosomes - Protein synthesis
III. Chloroplasts - Lipid synthesis
IV. Vacuoles - Storage of substances
Which of the above pair(s) is/are correctly matched?
Explanation
Most listed organelle functions are correct: lysosomes perform digestion, ribosomes synthesize proteins, and vacuoles store various substances. However, the statement about chloroplasts is wrong; their primary role is photosynthesis, the process of converting light energy into chemical energy. Lipid synthesis is actually performed by the smooth endoplasmic reticulum, not by chloroplasts, which are exclusive to plants and some algae.
Q147. The primary function of the Golgi apparatus in a eukaryotic cell is:
Explanation
The Golgi apparatus serves as the central shipping and receiving department of the eukaryotic cell. It receives proteins and lipids from the endoplasmic reticulum, modifies them chemically, and then sorts them into membrane-bound vesicles for delivery to specific destinations, such as the cell membrane or lysosomes. This processing is essential for ensuring that cellular products are functional and reach locations.
Q148. Rough Endoplasmic Reticulum (RER) appears "rough" under a microscope due to the presence of which attached structures?
Explanation
The Endoplasmic Reticulum is a network of membranes within the cell. The "rough" variety, or RER, is named for its bumpy appearance under an electron microscope, which is caused by the presence of numerous ribosomes attached to its outer surface. These ribosomes are actively involved in the synthesis of proteins that are destined for secretion or for use in the cell membrane.
Q149. Chromoplasts are a type of plastid primarily responsible for:
Explanation
Chromoplasts are specialized plastids found in certain plant tissues, such as the petals of flowers and the skins of ripening fruits. Unlike green chloroplasts, chromoplasts contain carotenoid pigments that produce yellow, orange, and red colors. These vibrant colors play a crucial biological role by attracting pollinators like bees and birds or animals that help in the dispersal of seeds and fruits.
Q150. The currently accepted model describing the structure of the cell membrane is known as the:
Explanation
The fluid mosaic model is the currently accepted description of the cell membrane’s structure. It depicts the membrane as a dynamic, flexible phospholipid bilayer in which various protein molecules are embedded or attached. This "mosaic" of proteins can move laterally within the "fluid" lipid layer, allowing the membrane to perform essential functions such as selective permeability, cell signaling, and structural support.Answer key for these questions
| Q | Correct answer |
|---|---|
| 141 | (c) Robert Hooke |
| 142 | (d) All cells contain a true nucleus and membrane-bound organelles |
| 143 | (a) A distinct, membrane-bound nucleus |
| 144 | (b) Cell wall |
| 145 | (b) Generate cellular energy in the form of ATP |
| 146 | (a) I, II and IV |
| 147 | (c) Modification, sorting, and packaging of proteins |
| 148 | (d) Ribosomes |
| 149 | (c) Imparting colors other than green to flowers and fruits |
| 150 | (b) Fluid mosaic model |
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.