Everything Life Sciences Grade 10

10 Biodiversity and classification

10.1 Overview

Introduction DUMMY

‘Biodiversity is the greatest treasure we have. Its diminishing is to be prevented at all costs’.

— Thomas Eisner, US environmental scientist who has made some of the most interesting

findings into how organisms produce chemicals to fight off predation.

The diversity of life on Earth has fascinated scientists for generations. The earliest scientists

attempted to understand life partly by categorising it according to a range of common traits.

These classification systems have changed based on the new evidence gathered. In this

unit you will study the history of the system of naming organisms, starting with Aristotle

and progressing to the current five-kingdom system devised by Whittaker. You will also be

introduced to the scientific convention of referring to organisms in Latin using two names -

referred to as binomial nomenclature. It is important to try and draw connections between

this section and the previous one in which you studied the plant and animal life common to

each biome.

Key concepts

• There is enormous biodiversity on Earth consisting of different ecosystems containing
  a variety of species which each have genetic differences.


• South Africa is a ’hotspot’ of diversity and has a large diversity of species endemic to
  the region.


• Classification schemes are a way of categorising biodiversity based on common char-
  acteristics.


• The history of classification began with Aristotle.


• Currently, the most widely used classification system is the five-kingdom scheme con-
  sisting of the kingdoms: Animalia, Plantae, Fungi, Protista and Monera (or Bacteria).


• In Science we name living organisms using a naming system called binomial nomen-
  clature, which is written in the form:Genus, species


• Based on cell structure there are key differences between prokaryotes and eukaryotes.


• The main groupings of living organisms are bacteria, protists, fungi, plants and animals.
  The features that allow us to determine which is which must be understood.

10.2 Biodiversity

Biodiversity is the term we use to refer to the variation in life forms in an ecosystem, biome

or the entire planet. The term also describes the genetic wealth within each species, the

inter-relationships between them and the natural areas in which they occur.

In this chapter we will focus on understanding the existing biodiversity and how scientists

294 10.1. Overview