Subject:
Biology
Type of Lesson:
Discovery, cooperative learning,
brainstorming
Grade:
10
CSEC OBJ:
A 1.1 Students should be able to
group living organisms according to
observed similarities and differences
(Expansion of obj. A 1.1)
Term:
Christmas
UNIT: 1
Classification
Duration:
40 mins
Lesson 2:
Grouping and Naming Organisms
Week: 1
Objectives
As a result of this lesson, you will be able to:
1) Suggest reasons why taxonomy (identifying, classifying and naming organisms) is an
important aspect of biology.
2) Suggest various criteria that may be used in the classification of a given group of organisms
3) Group living organisms according to observed similarities and differences.
4) Describe the taxonomic hierarchy used by scientists in the classification of organisms.
5) Demonstrate the correct protocol in the writing of scientific names.
Prerequisite Student Knowledge
You should be familiar with:
1) Characteristics of living things.
2) Introduction to differences and similarities between plants and animals.
3) Lesson 1 – Classification and Keys
Important Points
Important points in this lesson:
1) Variation exists among living things, this variation can be used to classify organisms.
2) The use of scientific names allows us to differentiate accurately between organisms.
Key Terms
Taxonomy
Nomenclature
Binomial
Species, Genus
Family, Order, Class
Phylum, Kingdom
Challenge Areas
Students can research the various divisions into which plants fall and the characteristics of each
division. Notes should be made of each one.
Equipment/Material Needed
Worksheets will be provided for you by your teacher.
Note to Student
Your ability to make detailed observations would be very useful here – record observations
accurately.
Introduction
1) Introductory Activity
a. The identification parade.
If you were given a list of five descriptions relating to a particular individual in
your class do you think that you would be able to identify the required person?
Let’s try it!
Important Point
The term used by
scientists to describe the
act of placing organisms
into groups according to
observed similarities and
differences is
classification.
i. Look carefully at the individuals placed at the front of the class by your
teacher. Listen to the descriptions that your teacher is reading. Can you
determine who the individual is after the first description is read? Why not?
What happens as you teacher gives more and more descriptions?
ii. Give the name of the student who needed to be identified.
b. Now answer the following questions:
i. What do you think was the aim of this activity?
ii. What features do all six students have in common?
iii. The students who are standing before the class are not close relatives. What
would you have noticed if these students were siblings, i.e. had the same
parents? Why are we still able to tell sisters or brothers apart?
iv. What is the feature that allows us to separate the student identified from all the
others – what makes him/her unique?
Body of Lesson
1) Why classify?
a. Biologists are not the only persons who use classification – in fact we all do in our
everyday lives, we are constantly placing things into groups.
i. Get into a group with two of your peers. One member of your group must
read the questions given by the teacher and ensure that the discussion remains
on track, the other should record the group’s answer, and you should be
prepared to communicate the findings to the class.
Notes
Taxonomy is that the
branch of biology
concerned with
identifying, naming and
classifying organisms.
Think of a situation in everyday life in which classification is used. Identify the
objects that are classified and list the criteria used to classify them. Suggest two
benefits associated with the use of classification in that situation.
ii. Share your response with the class.
iii. Listen to what your peers have to say and generate a list of reasons why
classification in general is important. Decide which of these reasons might
also apply to the classification efforts of biologists.
2) Taxonomic Hierarchy
a. Reflect again on the introductory activity, and answer the following questions:
i. What happened to the size of the group stepping forward as each
description was read?
ii. How helpful was this in determining the identity of the individual being
described?
iii. Modern day classification schemes used by biologists follow a similar
pattern.
3) When, why and how do scientists classify organisms?
Notes
Taxonomic hierarchy –
Related groups into
which organisms can be
placed that decrease in
size as one gets closer
to identifying the
specific animal. The
groups used in
descending order of size
are:
Kingdom, phylum, class,
order, family, genus and
species.
Form a small group with one more of your peers. Your teacher will provide each of
you with a copy of Worksheet 2.1 on grouping and naming things. Read the
information provided, discuss possible answers to the questions with your partner and
write answers in the spaces provided.
i. After you have completed your worksheet, participate in the discussion
guided by your teacher to ensure you’re your answers are accurate. Be sure to
ask any questions that might be on your mind concerning classification.
ii. What’s in a name? Why are names important? One reason is that it
sometimes provides us with useful information. Each student in the classroom
has at least two names. What kind of information do these names provide us
with?
iii. Each organism known to man has also been assigned a scientific name, as
you discovered on your worksheet. Scientific names indicate the groups to
which an organism belongs.
iv. List once again, the major categories or taxa that are used in the
classification of organisms. Your teacher will write your response on the board
and you will be guided through an exercise to classify humans using these
taxa. Be sure to participate in this exercise by answering the questions that
you teacher asks.
v. Now look at the finished product – various taxa to which man belongs:
Kingdom:
Phylum:
Class:
Order:
Family:
Genus:
Species:
Animalia
Chordates
Mammals
Primates
Homonidae
Homo
sapiens
The scientific name of man is a combination of the genus name and the species
name: Homo sapiens.
a. Do you recall the special protocol that should be followed when writing scientific
names? Be sure to summarize these in your notebook. Remember that although the
common name of an organism may change from place to
place, the scientific
name always remains the same!
Closure
In-Class Assignments
1) Complete the crossword puzzle on Worksheet 2.2 provided by your teacher.
Out-of-Class Assignment
1) Using the taxonomic hierarchy (kingdom to phylum), classify the domestic cat and one other
living organism.
2) Find out the common names and the scientific names of any five plants around your home or
community. Write a short description of each plant and state exactly where it was found.
Remember to follow the protocol for writing scientific names.
Supplemental
Glossary of Terms
Taxonomy
Nomenclature
The branch of biology concerned with
identifying, naming and classifying organisms
Giving of scientific names to organisms
Taxon
Plural – taxa. The name given to categories used
in classifying organisms i.e. species, genus,
family, order, class, phylum, kingdom
Species
Group of organisms which can mate to produce
fertile offspring. Smallest group in taxonomic
hierarchy.
CSEC Questions
There are no relevant CSEC questions for these concepts
Recommended Materials
http://anthro.palomar.edu/animal/animal_1.htm:
Bibliography
1) Atwaroo-Ali, L (2003) CXC Biology Macmillan Caribbean Publishers
2) Roberts, M. B. V. & Mitchelmore, J. (1985) Biology for CXC Thomas Nelson and Sons
Worksheet 2.1: Grouping and Naming Living Things
Instructions: You may visit the following website:
http://anthro.palomar.edu/animal/animal_1.htm
OR if it is not available you may read the following slightly modified excerpt and
answer the questions that follow. Take a look at the questions before you begin to
read, this will guide you.
Title: When, why and how did scientists begin classifying living things?
Before the advent of modern, genetically based evolutionary studies, European and
American biology consisted primarily of taxonomy, or classification of organisms
into different categories based on their physical characteristics. The leading
naturalists of the 18th and 19th centuries spent their lives identifying and naming
newly discovered plants and animals. However, few of them asked what accounted
for the patterns of similarities and differences between the organisms, since most
naturalists two centuries ago held the view that plants and animals (including
humans) had been created in their present form and that they have remained
unchanged. As a result, it made no sense to ask how organisms have evolved
through time.
One of the most important 18th century naturalists was a Swedish botanist and
medical doctor named Carolus Linnaeus. In 1735, Linnaeus published an influential
book in which he outlined his scheme for classifying all known and yet to be
discovered organisms according to the greater or lesser extent of their similarities.
This Linnaean system of classification was widely accepted by the early 19th century
and is still the basic framework for all taxonomy in the biological sciences today.
The Linnaean system uses two Latin name categories, genus and species, to
designate each type of organism. A genus is a higher level category that includes one
or more species under it. Such a dual level designation is referred to as a binomial
(literally "two names" in Latin) nomenclature. This is the organism’s scientific name
and it is internationally accepted – the same all around the world. For example,
Linnaeus described humans in his system with the scientific name Homo sapiens, or
"man who is wise"--Homo is our genus and sapiens is our species. In specific places
however local people may use common names to identify a specific organism e.g.
guinep (Jamaica) also called chennet (Trinidad) or ackee (Barbados) carries the
scientific name Melicoccus bijugatus.
Linnaeus also created higher, more inclusive classification categories or taxa
(singular: taxon) – in sequence from smallest to the largest group are as follows:
species, genus, family, order, class, phylum and kingdom. While the form of the
Linnaean classification system remains substantially the same, the reasoning behind
it has undergone considerable change. Today classification studies are used as
important tools in attempts to understand the theory of evolution.
Now that you have read the passage carefully, answer the following questions. You
may discuss possible answers with your group members from the previous activity.
1.
What is the name of the scientist primarily responsible for developing
the classification system that we use today?
______________________________________________________
2.
Suggest two differences between the scientific name and the common
name of an organism.
______________________________________________________
______________________________________________________
3.
Can you suggest why local names often seem to be more popular than
scientific names?
______________________________________________________
______________________________________________________
______________________________________________________
Worksheet 2.2: Let’s Review Classifying and Naming Organisms