Learning Intention: You will understand the characteristics that are used to define living organisms and how they are classified into groups.
Success Criteria: You will remember the six characteristics used to define life, the names of the Five Kingdoms of living organisms and create a poster that demonstrates your understanding of how vertebrates are classified.
This week we started a new unit of work – “What is Life?” – and you have learned about the characteristics of living organisms:
- Made of cells and the products of cells
- Require oxygen and nutrients
- Produce wastes
- Move and grow
- Reproduce themselves
- Respond to stimuli (light, touch, sound, odour)
Complete the three circle Venn diagram with these characteristics. We have learnt why it is important to identify living organisms – so we can communicate with others about dangerous and useful species.
Now we are going to learn about why we classify living organisms into groups – we have discussed the Five Kingdoms of Living Organisms – Plants, Animals, Fungi, Protists and Bacteria. They are grouped according to common characteristics – whether they can produce their own food or rely on other sources (autotrophs and heterotrophs), their cell type (single-celled or multicellular, with or without a cell wall, distinct nucleus and cell organelles or not) and how they reproduce (sexually or asexually).
Within each Kingdom there are smaller groups in a hierarchical, nested structure:
A ‘species’ is a group of organisms with similar characteristics that can interbreed to produce fertile offspring. Modern scientists (taxonomists) use DNA evidence to classify organisms into groups. Museums and herbariums usually have a ‘type’ specimen that is an example of the particulate species.
Today we are going to investigate how invertebrates (animals without backbones) are classified. There are six main groups:
- Protozoans – microscopic animals that consist of only one cell (unicellular) and live in water or as parasites inside other organisms.
- Coelenterates – soft, hollow-bodied organisms that mostly live in the sea. They have only one body opening and no body organs. They have special stinging cells called ‘nematocysts’.
- Worms – soft-bodies animals that can be flat, round or threadlike. Some have segmented bodies.
- Molluscs – soft-bodied organisms, often with a protective shell.
- Echinoderms – marine animals with tough, spiny skin and radial symmetry.
- Arthropods – animals with an exoskeleton (hard cuticle), a segmented body and jointed limbs. They are divided into four groups mainly on the basis of how many legs.
Create a table with these six headings. Go to “Arthur’s Clip Art” and copy and paste the different invertebrate groups into the correct column of your table. So, for example, snails and slugs are molluscs; seastars and sea urchins are echinoderms; jellyfish and sea-anenomes are coelenterates. Email me your work as an attachment to brittgow(at)gmail(dot)com.
Next week we will learn about classifying vertebrates (animals with backbones). There are five classes of vertebrates: Amphibians, Birds, Mammals, Fish and Reptiles. Some of the characteristics used to classify these animals are:
- Does it have fins, fur or scales?
- Does it lay eggs or give birth to live young?
- Can it maintain it’s own body temperature? (warm or cold-blooded)
- Does it have gills or lungs?
- Does it have mammary glands and feed it’s babies with milk?
There is one group of mammals that does not fit the pattern – a very ancient group that includes only two species of Australian native animals. Do you know what they are called?
Your homework is to create a poster that shows the characteristics of each of the five groups and a picture of at least one animal in each group (use clip-art, magazine pictures or draw your own).