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Review characteristics of living organisms
In the last lesson you learned seven characteristics of living organisms that distinguish them from non-living things.Spend a few minutes reviewing the terms and definitions. Use either the flash cards or the visual aid that you made.
Introduction to lesson
Being able to distinguish between living and non--living things is the first step in classification. But there is a wide variety of living organisms - from the tiny bacteria to the whale and redwood trees. It is therefore necessary to classify the different organisms into smaller groups that make it easier for us to study them. In this lesson, you will learn about the classification system biologists use to classify living organisms.
As you begin this lesson ask yourself the following questions:
- How do you think biologists classify living organisms?
- What criteria do you think biologists use when classifying living organisms? (Is it body shape, how the organism feeds or some other criteria?)
Classification
Read section 1.2 'Classification' on p.3-5 of the Coursebook.
Thinking it through
Answer the following questions to help you think through what you have read.
- Why do scientists classify living things?
- In describing the interesting fact that many organisms have similar features (like the mammals), the Coursebook takes an evolutionary approach and attributes that to a common ancestor. How do you feel about that approach? Do you think a divine design could explain this phenomenon?
- Scientists are now making use of DNA study to classify organisms. Is this a better method of classification than the study of body structure? Why or why not? What are some of the limitations of the earlier method? What do you think could be some of the limitations of the DNA method of classifying living organisms?
In your biology reference book, add the following terms and definitions
Definitions
morphology - the overall shape and form of an organism's body
anatomy - the detailed body structure of an organism
DNA - the chemical form which genes and chromosomes are made
chromosomes - a thread-like structure of DNA, made up of a string of genes
species - a group of organisms with similar characteristics, which can interbreed with each other to produce fertile offspring.
genus - a group of similar and related species
binomial system - an internationally agreed system in which the scientific name of an organism is made up of two parts showing the genus and the species.
Add any other term and its definition that you may be unfamiliar with.
Learning Activity 1
Answer the following comprehension questions in your exercise book.
- What did scientists use to classify living organisms?
- Who was the first person to try and classify living organisms?
- When did he live?
- Where was he from?
- How do scientists generally define a species?
- List the different levels of classification groups from the most general to the most specific.
- What is meant by the binomial name?
- Which part of the binomial name starts with a capital letter?
- Why do you think it is important to have a scientific name instead of using common or generic names?
Learning Activity 2
Answer in your exercise book. The purpose of this activity is to help you familiarize yourself with the classification system.
- Give the Kingdom, phylum, class, order, family, genus, and species of
- your favourite animal
- your favourite bird
- your favourite tree
- your favourite fish
- an insect.
Learning Activity 3
In your exercise book, answer Question 1.1 (a-c) on p.5 of the Coursebook.
Mark your work. The answers to Question 1.1 (Learning Activity 3) are at the back of the Coursebook on p.318 and the answers to Learning Activity 1 are LINK
Make a mind map or write a summary of this section. This will be an important part of your exam revision - so make it clear and make sure you have included all the relevant information.
Common misunderstandings and misconceptions
- The Latin names of the binomial are often written incorrectly. Usually the mistake is giving a capital letter to the species. Make sure you know that the genus has a capital letter and the species has a small letter. For example, Panthera leo. (See the Study tip on p.5). Also note that in print the binomial is always in italics. Since you can't write in italics, you must underline the binomial.
- Generic names do not have capital letters, unless they begin a sentence. For example, lion.
Closing the lesson
- What new things did you learn in this lesson?
- What did you already know?
- Are you confused about anything? Ask your parent or teacher to help you.