Q141. Who is credited with the first discovery and naming of the "cell" in 1665?
Basics of Everyday Science: RAS Prelims MCQs
200 RAS Prelims MCQs on the basics of everyday science test the scientific method, the laws of motion, chemical bonding and the cell theory. The questions use daily-life examples, such as the recoil of a gun and the orbit of a satellite, and the explanations give the principle behind each example so that you can reason out similar questions.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 141–150 of 200 questions
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 Basics of Everyday Science
- Inductive reasoning draws a general conclusion from specific observations; a control variable is kept constant in an experiment; communicating the results is the last step of the scientific method.
- Newton’s second law relates force, mass and acceleration; the recoil of a gun illustrates the third law.
- Momentum is the product of mass and velocity; impulse is equal to the change in momentum.
- A satellite in uniform circular orbit is held by the centripetal force provided by gravity.
- Water (H₂O) and N₂ show covalent bonding; sodium chloride, MgO and CaF₂ are ionic.
- The classical cell theory does not say that all cells have a true nucleus.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Basics of Everyday Science?
This page has 200 practice MCQs on Basics of Everyday Science (Science and Technology). Each has the correct answer, and most have an explanation.
What is the product of mass and velocity called?
Momentum. Newton’s second law says that the rate of change of momentum is equal to the force applied, and impulse is equal to the change in momentum of a body.
Which law explains the recoil of a gun?
Newton’s third law of motion. The gun pushes the bullet forward, and the bullet pushes the gun back with an equal and opposite force, which is felt as recoil.
What holds a satellite in a circular orbit?
The centripetal force provided by gravity. The Earth’s pull keeps changing the direction of the satellite’s velocity so that it moves in a circle and does not fly off in a straight line.