Essential Biology Notes
Subject Overview
Essential Biology is the opening theory paper of the B.Sc Medical Laboratory Science program, building the biological foundation the rest of the degree assumes. It starts with biology's branches and career scope within medical laboratory sciences, moves through tissue structure (epithelial, connective, muscular, nervous), and gives a detailed treatment of the cell — prokaryotic vs eukaryotic structure, the fluid-mosaic membrane model, organelles, and cell division. It closes with the molecules of life (carbohydrates, lipids, proteins, nucleic acids) and the basics of heredity, from Mendel's laws through DNA structure and replication. A 4-credit core theory paper across 5 units.
Subject at a glance
5
Units
37
Topics
4
Credits
5
Infographics
Unit-wise Syllabus
5 units — open any unit for detailed topic-wise notes, diagrams and important exam questions
- Biology and its branches
- scientific methods in biology
- scope of biology and career options in Medical Laboratory Sciences
- 1
Observation
- 2
Question
- 3
Hypothesis
A testable explanation
- 4
Experiment
Controlled test
- 5
Analysis of results
- 6
Conclusion
Accept, reject or refine
Study guide
This opening unit places biology in the context of a medical laboratory career: the branches of biology, the scientific method and the scope of careers in Medical Laboratory Sciences. Think of every later paper as an application of these basics to diagnosing disease.
- Structure and function of epithelial
- connective
- muscular and nervous tissue
Epithelial
Covers surfaces and lines cavities
Connective
Supports and binds: bone, blood, cartilage
Muscular
Contraction: skeletal, smooth, cardiac
Nervous
Carries electrical signals
Study guide
Tissues are groups of similar cells working together. You study the structure and function of epithelial, connective, muscular and nervous tissue, the same tissues a pathologist examines under the microscope. Learn to identify each tissue type from its picture.
- Cell theory
- prokaryotic and eukaryotic cells
- unicellular and multicellular organisms
- ultrastructure — cell wall
- cell membrane (fluid-mosaic model)
- membrane transport
- exocytosis and endocytosis
- cell organelles (nucleus, mitochondria, plastids, endoplasmic reticulum, Golgi complex, lysosomes, microtubules, centriole, vacuole, cytoskeleton, cilia and flagella, ribosomes)
Nucleus
No true nucleus (nucleoid)
True nucleus with membrane
Organelles
No membrane-bound organelles
Mitochondria, ER, Golgi and more
Ribosomes
70S
80S in cytoplasm
Examples
Bacteria
Animals, plants, fungi
Study guide
The cell is the unit of life. You study cell theory, prokaryotic and eukaryotic cells, the cell membrane and fluid-mosaic model, transport, endocytosis and exocytosis and every organelle from nucleus and mitochondria to ribosomes and the cytoskeleton. Draw a labelled eukaryotic cell and write one function beside each organelle.
- Inorganic and organic materials — water
- salts
- mineral ions
- carbohydrates
- lipids
- amino acids
- proteins
- nucleotides
- nucleic acids (DNA and RNA)
- binary fission
- mitosis and meiosis
Divisions
One
Two
Daughter cells
Two, identical, diploid
Four, different, haploid
Crossing over
No
Yes, in prophase I
Purpose
Growth and repair
Gamete formation
Study guide
You study the molecules of the cell (water, salts, carbohydrates, lipids, amino acids, proteins, nucleotides, DNA and RNA) and cell division by binary fission, mitosis and meiosis. Learn the phases of mitosis and meiosis with a simple diagram of each.
- Heredity and variation
- Mendel's laws of inheritance
- chromosomal basis of inheritance
- incomplete dominance
- multiple allelism
- quantitative inheritance
- genome
- linkage and crossing over
- gene mapping
- recombination
- DNA structure and replication
- RNA structure and role in protein synthesis
- 1DNA
Stores genetic information
- 2Replication
DNA copies itself
- 3Transcription
DNA to mRNA in the nucleus
- 4Translation
mRNA to protein on ribosomes
- 5Protein
Does the cell's work
Study guide
You study heredity and variation: Mendel's laws, chromosomal inheritance, incomplete dominance, multiple alleles, quantitative inheritance, linkage, crossing over, gene mapping, recombination, DNA structure and replication and the role of RNA in protein synthesis. Practise Mendelian cross problems with a Punnett square.
Why Essential Biology Matters
Cell biology and genetics are the foundation of every diagnostic test you will perform, from blood counts to molecular tests. A confident grasp of cells, tissues and inheritance makes pathology, haematology and microbiology far easier to understand.
How to Prepare for Essential Biology
- Draw and label cells, organelles and cell-division stages repeatedly until you can do so from memory.
- Use microscope slides in practicals to connect diagrams with real tissue.
- Practise genetics problems with Punnett squares and ratios.
Essential Biology: Frequently Asked Questions
Why do Medical Lab Science students study biology?
Because laboratory tests examine cells, tissues, molecules and genes, so understanding normal biology is essential to recognising what is abnormal.
What is the difference between mitosis and meiosis?
Mitosis produces two identical body cells for growth and repair, while meiosis produces four genetically different sex cells with half the chromosome number.