aim: why do scientists need to classify organisms? aim: why do scientists need to classify...

CLASSIFICATIONMonday, June 13, 2011 – LESSON 2

AIM:Why do scientists need to classify organisms?

OUTCOMES:Level E: I can know that organisms are classified in to kingdomsLevel D: I can explain how organisms are classified Level C: I can describe why scientists need to classify organisms and explain its uses in society

STARTER:

• WHICH IS THE ODD ONE OUT?

• For each option, decide amongst your group which is the odd one out

Why do we need to classify species?

• Scientists estimate that there are about 2 million types of living things on earth

• Many more are yet to be discovered... They estimate that there could be anywhere up to 30 million different types of living organisms

What is Classification?

• Sponges used to be classed as plants but they are actually animals.

• Aristotle was one of the first people to sort organisms into groups based on their characteristics

• This is called CLASSIFICATION

Classification Today

• Scientists look at the cells of organisms to decide if they are in the Plant Kingdom or the Animal Kingdom.

1. Which cell is the animal cell?

2. How can you use these cells to classify organisms?

Other KingdomsMembers of the Fungus

kingdom do not make their own food.

Members of the Protoctista Kingdom are simple and often single-

celled

Members of the Prokaryote Kingdom are very small

single celled and have no nuclei in their cells

Quick Recap...

What are the five kingdoms?

(this would be part of the level E outcome)

Answer: Animal, Plant, Protoctista, Prokaryote, Fungi

What About Viruses?

Viruses

• There is no kingdom for viruses because most scientists do not think of them as being alive.

• When viruses get into living cells they change the way the cell works and cause it to make copies of the virus

• The actual virus is not living

What questions could you ask to subdivide the Animal Kingdom?

• Is it bigger than a dog?• Does it have a backbone?• Is it covered in feathers?• How many legs does it have?• Where does it live?

• Which of these questions is the most important?

How is the Animal Kingdom Subdivided?

• In 1797 the duckbill platypus was discovered • They were sent back to the UK but scientists

thought they were a practical joke

Scientists could not agree how to classify a poisonous, furry animal with a duck’s beak, a beaver’s tail, and otter’s feet and a lizard’s skeleton shape,

that lays leathery eggs

They all agreed that the platypus was a vertebrate.

What is the purpose of a backbone?

Give two examples of:a) Vertebrates

b) invertebrates

Animal Classification

Vertebrate features

Kingdoms

7 LEVELS OF CLASSIFICATION

• The different groups of vertebrates are split into smaller groups which have more characteristics in common

• These groups are called species

What is a Species?

• A species is a group of organisms that can interbreed and produce offspring that are fertile (can make babies)

Hybrids – What were they thinking?

Or the ‘how to name a really silly looking animal badly’ game

Guess the hybrid…

Zeedonk

Zebra and Donkey

In South Africa they are called zonkeys and are fairly common where zebras and donkeys are found in proximity to each other. Like mules, however, they cannot usually breed, due to an odd number of chromosomes disrupting meiosis.

Guess the hybrid…

Liger

Lion and Tiger

A Liger looks like a giant lion with diffused stripes. Some male ligers grow sparse manes. Like tigers, but unlike lions, ligers enjoy swimming.

Guess the hybrid…

Cama

Camel and Llama

Though born even smaller than a Llama calf, the Cama had the short ears and long tail of a camel, no hump and llama-like cloven hooves rather than the dromedary like pads. The Cama apparently inherited the poor temperament of both parents

Guess the hybrid…

Zorse

Zebra and Horse

The zorse is shaped more like a horse than a zebra, but has boldly striped legs and, often, stripes on the body or neck. Like most other interspecies hybrids, it is infertile.

Guess the hybrid…

Wholphin

Whale and Dolphin

A wolphin or wholphin is a rare hybrid, formed from a cross between a bottlenose dolphin Tursiops truncatus (mother), and a false killer whale Pseudorca crassidens (father). The wolphin's size, colour and shape are intermediate between the parent species. Named Kekaimalu, she has 66 teeth - intermediate between a bottlenose (88 teeth) and false killer whale (44 teeth). The wolphin proved fertile.

Key Points

• Animals of the same species have the same number of chromosomes (sections of genetic information)

• Different species cannot usually interbreed- but sometimes do to produce a hybrid.

• Often the hybrid offspring is infertile – due to the amount of chromosomes it has

Plenary – What have we learned so far?

• Why do scientists need to classify organisms?

• What are the five kingdoms?

• What is the difference between a vertebrate and an invertebrate?

• What are the seven levels of classification?

• What is a hybrid?

CLASSIFICATION – PART 2Monday, June 13, 2011 – LESSON 3

AIM:How do scientists classify organisms?

OUTCOMES:Level E: I can describe how organism are classified and list some basic features of each kingdomLevel D: I can explain how organisms are classified at the cellular level Level C: I can explain how organisms are classified and describe the differences at a cellular level

Cell Structure

• What do organisms of each kingdom have in common?

– USUALLY, the most basic thing that organisms of the same kingdom have in common is their cell structure

Examples of Cell Structures

Task – 20 minutes

• Using the microscope slides that you are given.

• Find the cell and draw a quick sketch of the cells you see

• Based on the cell structure, state whether you think it is animal, plant or neither

• Write your names and the name of the species on top of the piece of paper.

Plenary

• Card sort• Match the cell type to the characteristics listed

in your groups