Comprehensive Review Flashcards: Social Media, STEM, Computing & Current Affairs

This flashcard set (100 cards) covers key facts from the provided lecture notes: record-breaking social-media milestones, essential biology, physics, chemistry, computer science concepts, cybersecurity, notable scientists, Indian IT current affairs, and quiz-worthy trivia. Use these Q&A cards for rapid revision and exam practice across multiple subjects.

Which video was the first on YouTube to surpass 1 billion views, and when did it achieve this?

Psy’s “Gangnam Style” in December 2012.

As of March 2025, which YouTube video is the only one to have passed 15 billion views?

“Baby Shark Dance.”

What is the most-liked video on YouTube as of January 2025 and roughly how many likes does it have?

MrBeast’s “Would You Fly to Paris for a Baguette?” with ~55 million likes.

Which YouTube video holds the record for most dislikes?

YouTube Rewind 2018: “Everyone Controls Rewind.”

What Instagram post is the most-liked of all time and approximately how many likes does it have?

Lionel Messi lifting the FIFA World Cup 2022 trophy (~75 million likes).

What account posted the famous brown egg that once topped Instagram, and when?

@worldrecordegg on January 4, 2019.

Which chess-themed Instagram collaboration between footballers earned over 42 million likes?

Messi vs Ronaldo playing chess in a Louis Vuitton ad.

What was the first tweet ever sent and by whom?

“just setting up my twttr” by Jack Dorsey on March 21, 2006.

In what year did Twitter double its character limit from 140 to 280?

2017.

Who acquired Twitter in October 2022 and later rebranded it as X?

Elon Musk.

What biological process converts light energy into chemical energy, and in which organelle does it occur?

Photosynthesis; it occurs in the chloroplasts.

Which cell organelle is dubbed the “powerhouse of the cell” and why?

Mitochondria, because they perform respiration to release ATP.

During which phase of the cell cycle does DNA replication occur?

The S phase of interphase.

What is the end product count and ploidy of meiosis?

Four varied haploid cells.

Which molecule is considered the cell’s energy currency?

ATP (Adenosine Triphosphate).

Name the enzyme found in saliva that begins starch digestion.

Amylase.

Which model organism is widely used for regeneration studies?

The axolotl.

Why is Saccharomyces cerevisiae famous in molecular biology?

It was the first eukaryote to have its genome fully sequenced.

Who is known as the Father of Genetics and what organism did he study?

Gregor Mendel; he studied pea plants.

Which scientist’s X-ray diffraction image was pivotal in solving DNA’s structure?

Rosalind Franklin.

Which human body system includes the brain and spinal cord and controls coordination?

The nervous system.

What gene-editing technology won a Nobel Prize and is widely used today?

CRISPR-Cas9.

Which video game–like animal can survive extreme conditions including space and radiation?

Tardigrades (water bears).

What is the smallest known cell type?

Mycoplasma.

State Newton’s Second Law of Motion in formula form.

F = m a.

Which thermodynamic law states that entropy of an isolated system always increases?

The Second Law of Thermodynamics.

Write Ohm’s Law.

V = I R.

What law explains the bending of light between two media with different refractive indices?

Snell’s Law.

What SI unit is used to measure force?

Newton (N).

Which wave phenomenon involves alternating bright and dark fringes, demonstrated by Young’s double-slit experiment?

Interference (and diffraction).

Name the physicist who unified electricity and magnetism through four famous equations.

James Clerk Maxwell.

Who first detected gravitational waves in 2015 confirming Einstein’s prediction?

The LIGO collaboration.

State the approximate value of the speed of light in vacuum.

3 × 10⁸ m/s.

Which constant is symbolized by h and what does it represent?

Planck’s constant; it relates photon energy to frequency and underpins quantum theory.

Which branch of physics deals with heat and energy transfer?

Thermodynamics.

What scientific oddity describes light behaving as both a wave and a particle?

Wave-particle duality.

Which chemistry branch focuses on carbon-based compounds?

Organic Chemistry.

What is Avogadro’s number and what does it define?

6.022 × 10²³; the number of particles in one mole.

Name the law stating that at constant temperature, the pressure of a gas is inversely proportional to its volume.

Boyle’s Law.

Which reaction produces ammonia for fertilizers and who invented it?

The Haber Process, invented by Fritz Haber and Carl Bosch.

Identify the pH range that defines an acid.

Less than 7 on the pH scale.

Which purple compound is a common oxidizing agent and quiz favorite for color questions?

Potassium permanganate (KMnO₄).

Who arranged the Periodic Table by atomic number?

Dmitri Mendeleev.

Which chemist is called the Father of Modern Chemistry and coined the term oxygen?

Antoine Lavoisier.

What element is most abundant in the universe?

Hydrogen.

Which two metals are liquid at, or near, room temperature?

Mercury (liquid at room temp) and gallium (melts in your hand).

What is the only bird capable of flying backward?

The hummingbird.

Name the first electronic computer and its year of completion.

ENIAC, completed in 1945.

Who is referred to as the Father of Theoretical Computer Science and AI?

Alan Turing.

Define Moore’s Law.

The number of transistors on a microchip doubles about every two years.

What does CPU stand for, and what is its primary role?

Central Processing Unit; it executes instructions and acts as the computer’s brain.

Differentiate between RAM and ROM in one sentence.

RAM is volatile temporary memory; ROM is non-volatile permanent memory.

What networking device connects multiple networks together?

A router.

Which protocol secures web traffic by encryption and uses port 443 by default?

HTTPS (Hypertext Transfer Protocol Secure).

Name the inventor of the World Wide Web and the year it was proposed.

Tim Berners-Lee, 1989.

What does VPN stand for and what is its key benefit?

Virtual Private Network; it encrypts and hides internet traffic and location.

Explain the difference between a compiler and an interpreter.

A compiler translates entire source code into machine code before execution, whereas an interpreter executes code line by line.

Which programming language was created by Dennis Ritchie in 1972?

C.

What keyboard layout is most common worldwide and why is it named so?

QWERTY; named after its first six letters on the top letter row.

What is the smallest unit of digital data?

A bit.

Which key combination typically opens Task Manager in Windows?

Ctrl + Alt + Del.

Who created Linux and in what year?

Linus Torvalds in 1991.

What is phishing in cybersecurity terms?

Fraudulently tricking users into divulging sensitive information.

Define ransomware.

Malware that encrypts files and demands payment for decryption.

Which device converts AC to DC power inside a computer?

Power Supply Unit (PSU).

What is the numerical size of a kilobyte in bytes (binary definition)?

1,024 bytes.

What social media platform was launched on April 1, 2004 and by whom?

Gmail, launched by Google.

What does ASCII stand for?

American Standard Code for Information Interchange.

Name the first computer virus and its release year.

“Creeper,” 1971.

Which social-media-centric keyboard layout bumps appear on which keys to aid touch typing?

Small bumps on the F and J keys.

Who invented the computer mouse and what was its original name?

Douglas Engelbart; originally called the “X-Y Position Indicator.”

Define deepfake.

AI-generated synthetic media that convincingly alters video or audio to mimic real people.

Which statisticians devised the Duckworth-Lewis method in cricket?

Frank Duckworth and Tony Lewis.

What is the full form of 2FA and why is it important?

Two-Factor Authentication; it adds an extra verification step to enhance security.

Which Indian IT giant announced ~12,000 layoffs (≈2% workforce) for FY 2026?

Tata Consultancy Services (TCS).

Why did TCS face criticism during its 2025 layoffs?

Because CEO K. Krithivasan received ₹26.52 crore compensation while layoffs were occurring.

Which company named TCS its 2025 “Delivery Excellence Partner of the Year”?

Databricks.

How much is TCS investing in infrastructure expansion across Indian cities?

Over ₹4,500 crore.

What is TCS’s brand valuation in 2025?

USD 21.3 billion.

Which social media founders created YouTube in 2005?

Steve Chen, Chad Hurley, and Jawed Karim.

What practice allows web addresses to be converted into IP addresses?

DNS (Domain Name System).

Which Internet protocol version uses 128-bit addresses?

IPv6.

Which law of chemistry states that matter cannot be created or destroyed?

Law of Conservation of Mass.

What gas law states V ∝ T at constant pressure?

Charles’s Law.

Which molecule is responsible for most structural protein in the human body?

Collagen.

Identify the strongest bone in the human body.

The femur.

Which nerve is the longest in the human body?

The sciatic nerve.

Name the scientific principle behind generators and transformers.

Faraday’s Law of Electromagnetic Induction.

Which phenomenon causes star light to shift toward the red end of the spectrum in an expanding universe?

Redshift.

What is E = m c² an expression of and who formulated it?

Mass–energy equivalence; formulated by Albert Einstein.

What is the main purpose of a firewall in networking?

To control and filter incoming and outgoing network traffic.

Which Nobel-winning Indian physicist discovered Raman scattering?

C. V. Raman (Nobel Prize 1930).

What theory explains the uncertainty and dual nature of particles?

Quantum mechanics (Heisenberg uncertainty principle and wave-particle duality).

Name the constant 6.022 × 10²³ and its symbol.

Avogadro’s Number, Nₐ.

Which Nobel Prize–winning discovery showed bacteria can cause disease and led to pasteurization?

Louis Pasteur’s germ theory of disease.

Who discovered penicillin and in what year?

Alexander Fleming in 1928 (published 1929).

What is the SI unit for electrical resistance?

Ohm (Ω).

Which SI unit measures frequency?

Hertz (Hz).

What physics effect involves electrons emitted from a metal when light shines on it, and who explained it?

Photoelectric effect; explained by Albert Einstein.

Define superconductivity in one sentence.

A state in which a material exhibits zero electrical resistance at very low temperatures.