1. Kingdom Proyaryota (bacteria) Kingdom Protoctista
Dichotomous key
Kingdom Proyaryota (bacteria)
Kingdom Protoctista
by Hazel 6S (23)

2. Dichotomous keys
A device for easy and quick identification of unknown object.
Construction of a dichotomous key:
- Use constant characteristics
-  Use quantitative X (e.g. big, small ……)
- Precede the descriptive terms with the name of the anatomical part to which it applies.

3. When using a key, please remember :
Always read both choices.
Be sure you understand the meaning of the terms involved.
When measurements are given, use a calibrated scale.
Since living things are always variable, do not base your conclusion on a single observation. Study several specimens to be sure your specimen is typical.

4. Examples of Dichotomous keys
1a. Organisms lacking cell nuclei Prokaryotae
1b. Organisms with cell nuclei
2a. Unicellular or tissue-level organisms . . Protista
2b. Complex, multicellular organisms
3a. Organisms autotrophic Plantae
3b. Organisms heterotrophic
4a. Organisms absorb food Fungi
4b. Organisms ingest food Animalia

8. Kingdom prokaryota (Kingdom Monera)
Prokaryotic organisms (bacteria)
Bacteria
Tiny (diameter: um)
Unicellular
Occur in clusters or filaments
Spherical, rod-shaped and helical
Survive even under extreme conditions
Flagella ( motile )
Prokaryotic organisms (bacteria)
Bacteria
Tiny (diameter: um)
Unicellular
Occur in clusters or filaments
Spherical, rod-shaped and helical
Survive even under extreme conditions
Flagella ( motile )

10. Reproduction
Reproduce asexually ( binary fission )

11. Reproduce sexually ( conjugation )

12. 3 types of survival ways Heterotrophs(most) Autotrophs (some)
e.g. blue green algae (cyanobacteria) green sulphur bacteria purple sulphur bacteria
Chemoautotrophs

13. Archaebacteria & Eubacteria
Eubacteria (true bacteria)
Shape
Various shape
Cell wall
X Peptidoglycan
Peptidoglycan
Cell membrane
Branched chain ether linked lipids.
Straight chain ester with lipids.
tRNA
X thymine
thymine
Interaction with other organisms
mutualism
commensal
mutualists
predators
pathogens
Significance in technology and industry
Thermostable enzymes, sewage treatment, antibiotics, organic solvents, production of biogas
Fermented foods, bioremediation, waste processing, agrichemicals, biological pest control, scientific research

14. Kingdom Subkingdom Major group Prokaryotae Eubacteria ( true bacteria)
Heterotrophic eubacteria
Photosynthetic
Chemosynthetic
Archaebacteria
Methanogens
Halophiles
Thermophiles

15. Kingdom Protoctista Some: unicellular some: multicellular
 nuclei and other characteristically eukaryotic properties
Size: microscopic form – giant form
Motile ( pseudopodia, cilia, flagella )
Aquatic
3 subgroups : algae, protozoans, slime moulds

16. Algae Plant-like protoctists X many plant structures
Cellulose cell wall
Non-motile
Undergo photosynthesis
X many plant structures
Subgroup
Phylum
Distinguishing feature
Photosynthetic pigments
Algae
Chlorophyta (green algae )
Unicellular / multicellular
Cellulose cell wall
Chlorophyll
Phaeophyta (brown algae)
Chlorophyll & fucoxanthin
Bacillariophyta (diatoms)
Cell wall with a kind of silica
Various

17. Protozoa Animal-like unicellular protoctists Motile
X cell wall & chlorophyll
Obtain nutrients by engulfing other organisms
Subgroup
Phylum
Distinguishing features
Protozoa
Phytoflagellata (plant flagellates)
Unicellular
X cell wall
≥1 flagella
chlorophyll
Zooflagellata (animal flagellates)
Heterotrophic
Sarcodina (amoebae)
-  pseudopodia
Ciliophora (ciliates)
Numerous cilia
2 nuclei

18. Slime moulds Fungi-like protoctists
Body consist of thread-like structures
X photosynthesis
Obtain nutrients through absorption from the surroundings
Different structural constituents and composition from fungi

19. END