Feb 12 (Dichotomous Keys)
Feb 12(The Five Kingdoms)
Learning Objectives
- Use and create a dichotomous key
- Compare and contrast the characteristics of the five kingdoms
- Compare and contrast prokaryotes and eukaryotes
- Identify the characteristics that differentiates the kingdoms from each other
What is a Dichotomous Key?
- A step-by-step key used to identify an organism, usually a plant or animal.
- Each step presents descriptions of two distinguishing characters with a direction to another stage in the key until the species is identified
Using a dichotomous key is actually quite simple.
- Start with the organism you want to identify
- Start with number 1 on the key
- Identify whether the organism has the characteristic in number one and follow the instructions to a) identify the organism or b) follow the directions and move to the next number.
- Continue until you arrive at the species.
An example of a dichotomous key for the woodpeckers above may look something like this
- Is the bird tan-coloured?
- Yes …. Go to number 2
- No ….. Go to number 3
- Does the bird have a red spot on its head?
- Yes… Northern flicker
- No … Gilded flicker
- Does the bird have white wing bars?
- Yes … Go to number 4
- No …. Williamson’s sapsucker
- Does the bird have black bars behind its eyes?
- Yes … Red-naped sapsucker
- No …. Red breasted sapsucker
The Five Kingdoms
The five kingdoms system separates all life on Earth into five categories:
| Kingdom | Characteristics | Energy Source |
| Monerans | Prokaryotic
Unicellular |
Heterotrophic
Autotrophic Chemotrophic |
| Protista | The “miscellaneous pile”
Unicellular Eukaryotic Have characteristics of fungi, plants and animals |
Heterotrophic
Autotrophic And both |
| Fungi | Eukaryotic
Generally made of hyphae (thin strands of cells) Cell walls are made of chitin |
Heterotrophic |
| Plantae | Eukaryotic
Multicellular Cell walls out of cellulose Have chloroplasts |
Autotrophic |
| Animalia | Eukaryotic
Multicellular No cell walls or chloroplasts |
Heterotrophic |
Prokaryotes: are organisms whose cells lack a nucleus and other organelles. They are generally much smaller than eukaryotic cells.
Eukaryotes: are organisms whose cells contain a nucleus and other organelles.
Autotrophic: organisms which are able to obtain their food from inorganic sources such as light and chemicals
Heterotrophic: organisms which obtain their food from organic sources
Inorganic Substances: Non-living substances
Organic Substances: Substances that is derived from something that was or is alive.