Biology and its branches: one science of life, many ways to look

What Biology studies

Your book calls Biology the science of life. The word comes from two Greek words: "bios" (life) and "logos" (study). It explores the structures, functions and interactions of living organisms.

Biology is divided into three main fields. Zoology studies animals, Botany studies plants, and Microbiology studies microorganisms such as bacteria and microscopic fungi.

Inside these fields are branches, each asking one kind of question. Is it about form, inner structure, working, tissues or cells? About heredity, fossils, classification or surroundings? About disease, immunity or drugs?

Use the name to decode the branch. Cyto- is cell, histo- is tissue, palaeo- is ancient, patho- is disease. The table below lists every branch your book names.

Biology = bios (life) + logos (study). Three main fields: Zoology, Botany, Microbiology. Each branch is named after what it studies.

Key terms

Microbiology

Study of microorganisms: structure, habitats, reproduction, impact.

Anatomy

The internal physical structure of organisms.

Physiology

The functioning of body parts.

Palaeontology

The study of fossils and evolutionary history.

Short questions with model answers

1. Q1. Exercise A Q4: "Heart pumps blood, stomach digests food, and kidneys excrete wastes." Which branch does this come from?

   • Look at the verbs: pumps, digests, excretes.
   • Doing, not shape: Physiology.

   Physiology, option (a).

2. Q2. Short question B4: differentiate between Morphology and Physiology.

   • Morphology: form and structure.
   • Physiology: function.

   Morphology asks what a part looks like; Physiology asks how it works.

Common mistakes

• ✗ Swapping Cytology and Histology.

  ✓ Cytology is cells; Histology is tissues, groups of cells with similar functions.

• ✗ Calling the working of an organ its Anatomy.

  ✓ Anatomy is structure; Physiology is function.

• ✗ Listing only Botany and Zoology as the main fields.

  ✓ Your book names three: Zoology, Botany and Microbiology.

MCQs

1. 1. Which branch focuses on the structure and function of cells? (Exercise A Q1)

   1. (a) Cytology
   2. (b) Microbiology
   3. (c) Histology
   4. (d) Ecology
   Show answer

   (a) Cytology is the study of cells, the building blocks of life.

2. 2. The study of heredity and variation is known as: (Exercise A Q2)

   1. (a) Ecology
   2. (b) Anatomy
   3. (c) Embryology
   4. (d) Genetics
   Show answer

   (d) Genetics deals with transfer of characteristics from parents to offspring.

3. 3. Which branch studies the classification of organisms? (Exercise A Q5)

   1. (a) Physiology
   2. (b) Taxonomy
   3. (c) Palaeontology
   4. (d) Biogeography
   Show answer

   (b) Taxonomy groups organisms by similarities and differences.

4. 4. Development of an organism from a fertilized egg is studied in:

   1. (a) Morphology
   2. (b) Pathology
   3. (c) Embryology
   4. (d) Histology
   Show answer

   (c) Embryology, as in short question B2.

5. 5. Which is one of the three main fields of Biology?

   1. (a) Ecology
   2. (b) Microbiology
   3. (c) Genetics
   4. (d) Pathology
   Show answer

   (b) Zoology, Botany and Microbiology are the main fields; the rest are branches.

Quick revision

• Biology is the science of life: bios (life) + logos (study).
• Three main fields: Zoology, Botany and Microbiology.
• Branches split by question: structure, function, cells, tissues, heredity, fossils, disease, drugs.