Classification of Living Things

Learning intention for unit Characteristics of living organisms Classification of living organisms The hierarchical classification system Binomial system of naming species Simple dichotomous key

Success criteria of unit (I can…) list and describe the characteristics of organisms define the terms nutrition, excretion, respiration, sensitivity,

reproduction, growth and movement outline the use of a hierarchical classification system for living

organisms classify living organisms into kingdoms, orders, classes, families,

genera and species define and describe the binomial system of naming species construct dichotomous keys use simple dichotomous keys based on easily identifiable features.

Revision quiz List the 8 characteristics that are needed to be classified as

being living Define Biology Explain why we need to classify things List 3 areas of study within Biology. Classify the following as living, non-living or dead;

A. A leaf that is on a tree

B. A log that is lying on the forest floor

C. A fire

D. A human

How do we know if something is ‘living’? All living things are characterised as being able to do

seven things These are usually remembered by the mnemonic MRS

NERG

MRS

NERG

Can you guess what these

letters stand for?

The 8 characteristics of Living ThingsMovement – Animals move to find food and keep away

from predators, plants move to face the light

Reproduction – the ability to produce offspring to keep the species in existence

Sensitivity – responding and reacting to the environment

Nutrition – Animals need food for respiration, plants need minerals from the soil

Excretion – Getting rid of waste

Respiration – Turning food into energy

Growth – Growing larger and stronger becoming adult size

cells

Task You have three minutes to classify the

following fruit in anyway way you wish in your work book.

Binomial Scientific name All organisms have a ‘two’ (binomial) part scientific

name. e.g. Homo sapiens The first part a binomial scientific name is the

generic name or the name of the genus in which the organism belongs to. And always has a capital name.

The second part of the name always begins with a lowercase letter and identifies the particular member that belongs to the genus, this is known as the specific name.

Advantages of the scientific name Common names vary from language to

language, scientific names are universal. Sometimes the same common name applies

to different organisms.

Classification why? If you have ever been to a library, you will

know how much easier it is to find a book on a particular subject if the books are arranged in subject groups. When the librarian has a new book to add to the library, he or she will group it with books on a similar topic, according to a classification system.

CLASSIFICATION helps us to impose order and a general plan on the diversity of living things. Scientists have always tried to organize and classify the objects, including living organisms, around them. Classification can be defined as grouping organisms according to their structural similarities.

This means that organisms that share similar features are placed in one group. These groups are arranged from the largest group of organisms to the smallest group of organisms.

Materials used for identification You can identify a species using the following materialsThe whole speciesParts of the speciesGenetic materialIndirect evidence

Classification of Living Things Everything that

is living can be sorted into these

5 kingdomsKingdom Moneran

Protist Kingdom

Fungi Kingdom

Plant Kingdom

Animal Kingdom

Kingdom Moneran Tiny, single-celled organisms Do not have a nucleus E.g. bacteria

Protist Kingdom Single-celled organisms with a

nucleus Live in damp places of water E.g. amoeba

Fungi Kingdom Body is made up of a network of

threads called hyphae E.g moulds, mushrooms

Plant Kingdom Multicellular – made up of lots of

cells Make their own food by

photosynthesis Lots of examples: flowering

plants / non-flowering plants

Animal Kingdom Multicellular – made up of may

specialised cells Cannot make own food Can be further classified into

vertebrates and non-vertebrates then into classes such as amphibians, reptiles, birds, mammals

All kingdoms can be broken in small groups according common characteristics.

A detail classification should includes the following steps in the ladder.

Phylum – Second highest classification it covers different groups with a common physical characteristics.

Class – Grouped families according a shared attribute. (mammals)

Order– How the a class group survive? (carnivorous, herbivorous)

Family – Taxonomic group containing one or more genera.

Genus – The second smallest group

Species –Smallest group whose members can interbreed. The science of classifying things is called Taxonomy.

Classification goes beyond kingdom level

The five kingdoms

Complete the table

Classification keys Circular key Dichotomous key Field guide

Circular key

Circular keys can also be used to unlock identity. To read this type of key you start in the middle and work outwards, choosing one of the options in each layer. The final layer provides you with the solution of the organism’s identity. Carefully observe the dinosaurs on this page and consider features that could be used to separate them into groups. Consider how you could use these features in the design of a circular key that would enable each individual to be identified.

Dichotomous key

Dichotomous keys provide choices at each branch (dichotomous = ‘cutting in two’). Features such as size, colour, behaviour and habitat are not good for classification because they can change throughout the life of the organism. It is better to use the presence or absence of structural features or differences in these features.

Field guide

Field guides are a commonly used type of reference book to help people identify organisms. These guides are specially designed to assist you in ‘on-the-spot’ identification. They often contain brief written descriptions and pictures and are small enough to take outside when you are observing wildlife. There are also a number of electronic ‘field guide’ databases available.

Read and complete questions

Task You are to create a creature. Every one

must start their creature using a Styrofoam ball. You must also give your creature a name.

You will be getting into groups and creating a Dichotomous key based on your creatures and create a poster, then you will present you key to the class.