3.2 Life on earth

Natural sciences

Grade 8

Biodiversity

Module 22

Life on earth

All plants and animals are divided into groups according to their characteristics. Can you remember what we call the process by which this division is performed?

Classification

• Test your memory:

• Animals are divided into TWO main groups according to the presence or absence of a

• Animals that do not have an internal skeleton are known as

• Animals with an internal skeleton are known as

• Vertebrates are divided into

Activity: to classify information

• Cut out the pictures on this page and paste them on another sheet of paper under the propriate heading (Fish, Amphians, Reptiles, Birds, Mammals ). List three external features of each group. (Remember that features may not be visible in the pictures.)

Fish eagle Haliaeetus vocifer

Rhinoceros Diceros bicornis

Leguan Varanus niloticus

Common frog Rana temporia

Common carp Cyprinus carpio

Assessment of classification:

Could you apply the sketches correctly and list the correct features?

[ LO 2.2]

The classification of living organisms is performed according to an international system designed by scientists. This makes it possible for people from all language groups and from all over the world to know precisely which organism is meant when information is offered or received.

Carl Linnaeus (1707-1778), a Swedish doctor, botanist and zoologist, has had the most important influence on our present classification system.

• Names given to organisms are mainly of Latin origin (so it is “Greek” to most of us).

• Each organism bears a "NAME" and a "SURNAME".

• The name represents the species – it refers to similarities in structure, function and reproduction potential (the chromosome number is the same).

• The surname represents the Genus – it indicates a group of related species.

• The rule for writing this has INTERNATIONAL validity.

• The Genus name is written first and with an initial capital letter followed by lower case letters.

• This is followed by a space and the species name, using lower case letters throughout.

• If the name is printed, italic script is used. In hand-written format, the two words are underlined separately.

• The scientific name of the earthworm, for instance, is Lumbricus terrestris.

• This system is referred to as a BINOMINAL system (two names).

Activity: to apply a simple classification system

1. What is a biologist?

2. What is a botanist?

3. Write the scientific name of the earthworm according to the international rule:

4. Why is classification important?

5. What is the meaning of terre in the scientific name of the earthworm?.

6. Use of the information provided on the page of sketches and write the scientific name in one column and the common name in another column.

7. Examine the names of the different robins (birds)

• Chorister robin: Cossypha dichroa

• Heuglin’s robin: Cossypha heuglini

• Natal robin: Cossypha natalensis

• Cape robin Cossypha caffra

• Explain the meaning of the Genus and the species names as in the binominal classification system with reference to these names.

Assessment of APPLICATION:

Could you answer the questions?

[LO 2.4]

ASSIGNMENT [LO 1.2]:

• Do research on Carl Linnaeus as a scientist. Write a report of approximately 100 words.

Assessment

Learning outcomes 1: Scientific investigations

The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

This is evident when the learner

1.2 is able to conduct an investigation and collect data.

Learning outcomes 2: Constructing Science Knowledge

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

This is evident when the learner

• able to categorise information;

2.4 is able to apply knowledge.

Memorandum

Activity: APPLICATION OF CLASSIFICATION

• Explain classification and the binominal system.
• Sources dealing with Carolus Linnaeus.