Biology GK Questions for SSC CGL 2026: Top 30 Expected Biology MCQs with Answers

Cell Biology • Genetics • Animal Kingdom • Key Biological Facts — curated for SSC CGL, CHSL, MTS, Stenographer, and Railway exams.

Biology GK infographic for SSC CGL 2026 covering cell structure, DNA and chromosomes, and animal kingdom classification

Quick-revision infographic: cell organelles, DNA & chromosomes, and animal kingdom classification for SSC CGL 2026.

Why Biology Is Important for SSC Exams

Biology is one of the highest-scoring sections in the General Awareness syllabus for SSC CGL, SSC CHSL, Railway NTPC, Group D, MTS, and several other competitive examinations. Every year, direct questions are asked from cell biology, genetics, human physiology, animal classification, microorganisms, and plant biology.

Biology questions are generally factual and concept-based, which means candidates who understand the basic scientific principles can answer them quickly during the exam. This guide covers the most exam-relevant topics: cell biology, genetics, DNA, chromosomes, cell organelles, animal kingdom classification, and important scientific discoveries.

Cell Biology: Most Important Biology GK Topics

Cell Biology forms one of the strongest areas of Biology GK. Candidates should focus on:

  • Cell Theory
  • Protoplasm
  • Cell Membrane
  • Osmosis and Plasmolysis
  • Cell Wall
  • Nucleus
  • Ribosomes
  • Cell Organelles

Students should understand the function of every major organelle, since direct questions are frequently asked using nicknames such as:

  • Powerhouse of the Cell – Mitochondria
  • Brain of the Cell – Nucleus
  • Post Office of the Cell – Golgi Apparatus
  • Suicidal Bags of the Cell – Lysosomes
  • Father of Microbiology – Antonie van Leeuwenhoek

Genetics and DNA

Genetics remains one of the most frequently tested biology topics in SSC exams. Key areas to revise include:

  • DNA Structure & the Watson-Crick double helix model
  • Chromosomes and human chromosome number
  • DNA Replication and the Cell Cycle
  • S Phase of the cell cycle
  • Helicase enzyme
  • Histone Proteins
Key Fact: Humans have 46 chromosomes arranged in 23 pairs — 22 pairs of autosomes plus 1 pair of sex chromosomes (XX in females, XY in males). DNA replication occurs during the S (Synthesis) phase, and the enzyme helicase unwinds the DNA strands during this process.

Cell Organelles and Their Functions

A functional understanding of each organelle helps answer direct as well as application-based questions:

OrganelleImportant Function
NucleusControls cell activities
MitochondriaProduces cellular energy (ATP)
RibosomesProtein synthesis
Golgi ApparatusPackaging and transport
LysosomesIntracellular digestion
Rough Endoplasmic ReticulumProtein synthesis
Smooth Endoplasmic ReticulumLipid synthesis

Plastids — including chromoplasts and leucoplasts — also carry specialized functions and appear occasionally in exams. Lycopene gives tomatoes their red colour, and elaioplasts store oils and fats.

Key Fact: Mitochondria and chloroplasts have their own DNA and ribosomes, which supports the endosymbiotic theory.

Animal Kingdom and Classification

Animal Classification is another high-weightage Biology topic. Candidates should understand body symmetry, germ layers, coelom, segmentation, notochord, and characteristic examples of each phylum.

PhylumKey FeaturesExamples
PoriferaPore-bearing, simplest multicellular animals, no true tissuesSycon, Sponges
Coelenterata (Cnidaria)Radial symmetry, stinging cells (cnidocytes), two body layersHydra, Jellyfish, Sea anemone
PlatyhelminthesFlat, unsegmented body, bilateral symmetry, hermaphroditePlanaria, Tapeworm
Aschelminthes (Nematoda)Cylindrical, unsegmented body, pseudocoelomateAscaris, Pinworm
AnnelidaSegmented body, true coelom, closed circulatory systemEarthworm, Leech
ArthropodaJointed appendages, chitinous exoskeleton, largest animal phylumInsects, Crabs, Spiders
MolluscaSoft body, muscular foot, mantle present, radula in mostSnail, Octopus, Mussel
EchinodermataSpiny skin, water vascular system, radial symmetry (adults)Starfish, Sea urchin

High-Scoring Biology GK Facts

  • Antonie van Leeuwenhoek is known as the Father of Microbiology.
  • Robert Brown discovered the nucleus.
  • Rudolf Virchow proposed that all cells arise from pre-existing cells.
  • Watson and Crick proposed the double-helical structure of DNA.
  • Mitochondria possess their own DNA.
  • Ribosomes are formed in the nucleolus.
  • Golgi Apparatus packages proteins.
  • Lycopene gives tomatoes their red colour.
  • Elaioplast stores oils and fats.
  • DNA synthesis occurs during the S phase of the cell cycle.

Quick Revision Checklist

Before the examination, make sure you have revised:

  • Cell Theory
  • Cell Organelles
  • DNA & RNA
  • Chromosomes & Cell Division
  • Genetics
  • Animal Classification
  • Human Chromosome Number
  • Scientists and Their Discoveries
  • Biological Terminology
Exam Tip: Focus on NCERT diagrams, tables, and definitions. Practice previous-year questions to identify high-frequency topics and boost your score. Revise scientific names regularly, learn organelle functions, memorize scientists and their discoveries, and go through classification charts one final time before the exam.

Frequently Asked Questions

Who is called the Father of Microbiology?

Antonie van Leeuwenhoek is known as the Father of Microbiology.

How many chromosomes do humans have?

Humans possess 46 chromosomes arranged in 23 pairs.

Which organelle is known as the powerhouse of the cell?

Mitochondria is identified as the powerhouse of the cell.

Which organelle is called the brain of the cell?

The nucleus controls cellular activities and is commonly referred to as the brain of the cell.

During which phase does DNA replication occur?

DNA replication occurs during the S (Synthesis) phase of the cell cycle.

Which phylum is completely asymmetrical?

Porifera exhibits asymmetrical body organization.

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Conclusion

Biology remains one of the easiest scoring subjects in SSC CGL, SSC CHSL, Railway NTPC, and other government examinations. The topics covered in this guide — cell biology, genetics, chromosomes, organelles, and animal classification — represent the core concepts most frequently tested. Regular revision and consistent MCQ practice can help you improve both speed and accuracy in the General Awareness section.