Principles of Organisation

Principles of Organisation

Cellular Organisation

  • All life forms demonstrate a significant degree of organisation, starting at the cellular level.
  • Cells, as basic units of life, work in coordinated ways to ensure the survival and functioning of the organism.
  • While all cells share basic features, some are specialised to carry out distinct functions, such as sensory cells, muscle cells, or root hair cells in plants.

Tissues

  • A tissue is a collection of similar cells and their products, functioning together to perform a specific task.
  • Examples in humans: epithelial tissue (provides covering), nervous tissue (transmits nerve signals), muscle tissue (enables movement).
  • In plants: xylem tissue (transports water), phloem tissue (transports nutrients), meristematic tissue (enables growth).

Organs and Organ Systems

  • When different tissues work together to carry out a specific function, they form an organ.
  • Examples of organs: the heart, kidneys, lungs, leaf, or stem.
  • When organs work in synergy, they form an organ system.
  • In humans, examples of organ systems include the digestive system, respiratory system, and circulatory system.
  • Plants have fewer organ systems, but they also have a transport system (xylem and phloem).

Importance of Organisation in Biology

  • The level of organisation is a determinant of complexity in an organism, with advanced organisms demonstrating a high degree of structural organisation.
  • Homeostasis, which is required for life, depends on the functioning and coordination of the different levels of organisation.
  • Breaking down organisation, such as in diseases or injuries, can help understand the significance of organisation in maintaining life.

Enzymes and Digestion

  • Enzymes are biological catalysts responsible for regulating chemical reactions in all life forms.
  • They are highly specific and can be affected by temperature, pH, and substrate concentration.
  • Digestive enzymes, such as amylase, protease, and lipase, play a crucial role in breaking down large food molecules into smaller ones for absorption.
  • An understanding of enzyme functionality helps appreciate the complex metabolic activities at the cellular and organismal levels.

Digestive System

  • The digestive system is an example of a complex organ system in humans, involved in breaking down food, absorbing nutrients, and eliminating waste.
  • It comprises various organs, including the mouth, oesophagus, stomach, small intestine, large intestine, and rectum, each contributing a specific step in digestion.
  • Understanding the organisation of the digestive system and its functioning reveals how complex biological tasks are divided among different specialised parts.

Revisiting these principles and understanding how each level of organisation contributes to overall functioning will give a well-rounded perspective of biological organisation.