Biology Glossary G–M (Part 2)

Biology Glossary G–M (Part 2): Key Terms Every Student Should Know

Biology is built on precise terminology. This second part of our glossary covers essential terms from G to M, including gene, glycolysis, hormone, immune system, lysosome, meiosis, mitochondrion, and more. Each entry includes a clear definition, context, and links to authoritative sources. Whether you're preparing for an exam or expanding your scientific vocabulary, this guide will help you master these foundational concepts.

Biology glossary terms G–M – essential vocabulary for life sciences.

Quick Summary:

• G–H: Gene, genome, glycolysis, hormone, histology.
• I–K: Immune system, ion, karyotype, Krebs cycle.
• L–M: Lysosome, meiosis, mitochondrion, mitosis, mutation.

G–H Terms: The Building Blocks of Genetics and Metabolism

Gene: A segment of DNA that codes for a specific protein or functional RNA. Genes are the basic units of heredity. [Genome.gov]
Genome: The complete set of genetic material present in an organism. [Nature Scitable]
Glycolysis: The metabolic pathway that breaks down glucose into pyruvate, releasing energy (ATP) and NADH. Occurs in the cytoplasm. [Khan Academy]
Hormone: A chemical messenger secreted by endocrine glands that regulates specific physiological processes. [Britannica]
Histology: The study of the microscopic structure of tissues. [Britannica]

I–K Terms: Immunity, Ions, and Energy Cycles

Immune system: The body’s defense network against pathogens, including white blood cells, antibodies, and lymphoid organs. [Britannica]
Ion: An atom or molecule with a net electric charge due to loss or gain of electrons. Important in nerve impulses and cellular transport. [Britannica]
Karyotype: The number and appearance of chromosomes in the nucleus of a eukaryotic cell. Used to detect genetic abnormalities. [Genome.gov]
Krebs cycle (citric acid cycle): A series of chemical reactions that generate energy through the oxidation of acetyl‑CoA. Takes place in the mitochondrial matrix. [Khan Academy]

Tips for Mastering Biology Terminology

• Create flashcards with the term on one side and definition, diagram, and example on the other.
• Use mnemonic devices (e.g., “Mitochondria is the powerhouse of the cell”).
• Connect terms to real‑world applications (e.g., insulin as a hormone controlling blood sugar).
• Regularly quiz yourself using active recall.

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L–M Terms: Cellular Structures and Cell Division

• Lysosome: Membrane‑bound organelle containing digestive enzymes that break down waste materials and cellular debris. [Britannica]
• Meiosis: A type of cell division that produces four haploid gametes (sex cells), each with half the chromosome number of the parent. Essential for sexual reproduction. [Genome.gov]
• Mitochondrion: The organelle responsible for aerobic respiration, producing ATP; often called the “powerhouse of the cell.” [Britannica]
• Mitosis: Division of the nucleus resulting in two identical daughter cells with the same chromosome number; used for growth and repair. [Genome.gov]
• Mutation: A permanent change in the DNA sequence of an organism. Can be beneficial, harmful, or neutral. [Genome.gov]

Benefits of Learning Biology Glossary Terms

• Improved exam performance: Understanding precise definitions helps answer structured questions accurately.
• Better comprehension of advanced topics: Terms like glycolysis and meiosis are foundational to physiology, genetics, and evolution.
• Enhanced scientific literacy: You can read research articles and follow science news with confidence.
• Easier communication with peers and instructors: Shared vocabulary speeds up learning.

Frequently Asked Questions

What is the difference between mitosis and meiosis?

Mitosis produces two identical diploid daughter cells for growth and repair. Meiosis produces four genetically diverse haploid gametes for sexual reproduction. Mitosis involves one division; meiosis involves two divisions.

Why are mitochondria often called the “powerhouse” of the cell?

Mitochondria generate most of the cell’s supply of adenosine triphosphate (ATP), which is used as a source of chemical energy. Through aerobic respiration, they convert glucose and oxygen into ATP, carbon dioxide, and water.

How can I remember all these terms for my O Level exam?

Use spaced repetition with flashcards, draw labelled diagrams, and explain each term aloud as if teaching someone else. Linking terms to real‑life examples (e.g., insulin as a hormone) also reinforces memory.

Related Articles

• Biology Glossary A–F (Part 1) Live 
• Biology Glossary N–Z (Part 3) Live
• Cell Structure and Function: A Visual Guide Live

Conclusion

Mastering the Biology Glossary G–M (Part 2) terms is a vital step toward understanding life at the molecular, cellular, and systemic levels. From genes to mitochondria, each term opens a window into the complex machinery of living organisms. Continue to build your vocabulary, use active recall, and refer to trusted sources. Stay tuned for the final installment (N–Z) to complete your essential biology lexicon.