1. The Fundamentals of Life
1.2. Cell Theory
van Leeuwenhoek's microscope
Antonie van Leeuwenhoek is credited with constructing the first microscope.
- Size: matchbox
- Held close to the eye
- Magnification: 400x
van Leeuwenhoek was the first to describe sperm and (probably) bacteria, which he called "animalcules" ("little animals").
Hooke also drew what he saw through his microscope.
- Publishes "Micrographia" with detailed drawings of the "little life".
- Coins the term "cell"
In a sample from cork oak, Hooke sees what he describes looking like cells in a monastery. Although nobody at the time knew what a (biological) cell is, Hooke coined the term "cell".
A modern light microscope
A modern light microscope works essentially the same way as Hooke's microscope, although the design has changed quite a bit.
What characterizes a cell?
All cells have
- a cell membrane,
- cytoplasm (fluid-like intracellular substance), and
- DNA (in one or several chromosomes).
What the cell theory says
- All organisms consist of one or more cells.
- The cell is the fundamental living unit.
- New cells may only arise from other cells.
What do you need to build a cell?
Lipids are a diverse group of fat or fat-like molecules, insoluble in water.
Cell membranes are made of phospholipids.
The nucleic acids are DNA and RNA.
- Alternating sugar (S) and phosphate (P) residues.
- A always base pairs with T (in RNA, T is replaced with U), and vice versa.
- G always base pairs with C
- 1. The Fundamentals of Life
- 2. Cellular Structure and Function
- 3. Cellular Genetics
- 4. Mendelian Genetics
- 5. Evolution and Systematics
- 5.1. Roadmap to a Theory of Evolution
- 5.2. The Pillars of Evolution
- 5.3. Evidence for Evolution
- 5.4. Convergent and Divergent Evolution
- 5.5. Coevolution
- 5.6. Stabilizing and Disruptive Selection
- 5.7. Speciation
- 5.8. How to Build a Family Tree
- 5.9. The History of Life
- 5.10. The Formation of Life
- 5.11. The Divisions of Life
- 5.12. Plant Systematics
- 5.13. Animal Systematics
- 5.14. Chordate Systematics
- 5.15. Human Evolution
- 6. Ethology and Behavioural Ecology
- 7. Ecology: Systems of Organisms
- 7.1. Ecosystems
- 7.2. Nutritional Chains and Food Webs
- 7.3. Flow of Energy in an Ecosystem
- 7.4. The Water Cycle
- 7.5. The Carbon Cycle
- 7.6. The Nitrogen Cycle
- 7.7. The Phosphorous Cycle
- 7.8. Populations: Size and Growth
- 7.9. Communities. Living Together
- 7.10. Ecological Succession
- 7.11. From Bedrock to Litter
- 7.12. The Lakes
- 7.13. The Oceans and Seas
- 7.14. Climate and Biomes
- 8. Environmental Science
- 9. Viruses and Biotechnology
- 10. Plant & Fungal Physiology
- 10.1. The Organs of the Plants
- 10.2. Plants With and Without Seeds
- 10.3. The Root. How the Plant Absorbs Water and Nutrients
- 10.4. The Trunk and Water Transport
- 10.5. Structure and Function of the Leaf
- 10.6. Photosynthesis
- 10.7. How Plants Grow
- 10.8. How Plants Reproduce
- 10.9. Classification of the Fungi
- 10.10. How Fungi Reproduce
- 10.11. Fungal Parasites and Pathogens
- 11. Human Physiology
- 11.1. Physiology Basics
- 11.2. The Nervous System
- 11.3. The Senses
- 11.4. The Endocrine System
- 11.5. Food and Digestion
- 11.6. The Locomotor System
- 11.7. Gas Exchange and Circulation
- 11.7.1. Respirational Systems
- 11.7.2. Human Respiration
- 11.7.3. Circulation in Different Animals
- 11.7.4. The Human Circulatory System. Heart, Blood Vessels and Blood Pressure
- 11.7.5. Activity in the Capillaries
- 11.7.6. Blood Constituents
- 11.7.7. Blood Groups
- 11.7.8. Coagulation
- 11.7.9. Some Blood Diseases
- 11.7.10. Water Balance. Kidneys
- 11.8. The Immune System
- 11.9. Sex, Love, and STDs