(1.2-1.4) Eukaryotic, Prokaryotic, Pathogenic organisms

What are the 5 kingdoms of living organisms?

Animals

Plants

Fungi

Protoctists

Prokaryotes

Which of the kingdoms are eukaryotic organisms?

animals, plants, fungi, protoctists

What are eukaryotes?

• can be multi or single celled

• cells contain a nucleus with a distinct membrane

What are prokaryotes?

• always single celled

• smaller than eukaryotes

• no nucleus; nuclear material is in cytoplasm

Outline the main features of animals:

• multicellular

• usually have a nervous system

• no cell wall

• no chloroplasts- no photosynthesis

• carbohydrates stored as glycogen

e.g. mammals and insects

Outline the main features of plants:

• multicellular

• chloroplast- photosynthesis

• cellulose cell walls

• carbohydrates stored as starch or sucrose

e.g. flowering plants (maize), herbaceous legume (peas)

Outline the main features of fungi:

• some are single celled, some are multicellular

• usually cannot carry out photosynthesis

• body- mycelium made from thread-like hyphae with many nuclei

• chitin cell walls

• feed by saprotrophic nutrition

• may have carbohydrates stored as glycogen

e.g. Mucor- hyphae, yeast- single-celled

What is saprotrophic nutrition?

Process of feeding through the secretion of digestive enzymes onto food and absorption of the organic products

Outline the main features of protoctists:

• microscopic single-celled organisms

• some have animal cell features (Amoeba)

• some have plant cell features (Chlorella)

e.g. Plasmodium- causes malaria

Outline the main features of prokaryotic organisms: (bacteria)

• microscopic single-celled organisms

• have cell walls, cell membrane, cytoplasm, plasmids

• no nucleus- circular chromosome of DNA

• some can photosynthesise- with chlorophyll

• most feed off other organisms

e.g. lactobacillus bulgaricus, pneumococcus

What is a pathogen?

a disease causing microorganism

Which microorganisms are pathogens?

bacteria, fungi, protoctists, viruses

Outline the main features of viruses:

• non-living organism

• smaller than bacteria

• parasitic- can only reproduce inside living cells

• infect every type of living organism

• no cellular structure

• protein coat

• contain either RNA or DNA

e.g. HIV, influenza

Name a pathogenic bacterium:

M. tuberculosis- causes tuberculosis in humans

Name a pathogenic fungus:

Black Sigatoka- fungal disease in bananas

athletes foot- surface of skin

Name a pathogenic protoctist:

Plasmodium falciparum- causes severe malaria in humans