- They require Nutrition
- They respire
- They Excrete their waste
- They respond to there surroundings
- They move
- They control their internal condidtions
- They reproduce
- They grow and develop
- Plants: these are multicellular organisms; their cells contain chloroplasts and are able to carry out photosynthesis; their cells have cellulose cell walls; they store carbohydrates as starch or sucrose. Examples include flowering plants, such as a cereal (for example, maize), and a herbaceous legume (for example, peas or beans).
- Animals: these are multicellular organisms; their cells do not contain chloroplasts and are not able to carry out photosynthesis; they have no cell walls; they usually have nervous co-ordination and are able to move from one place to another; they often store carbohydrate as glycogen. Examples include mammals (for example, humans) and insects (for example, housefly and mosquito).
Section 1: The nature and
variety of living organisms
- (b) Variety of living organisms (common features shown by prokaryotic organisms)
- b) Variety of living organisms (common features shown by eukaryotic organisms)
- a) Characteristics of living organisms
- (b) Variety of living organisms (the term pathogen)
- Common Pathogen
- Fungi: these are organisms that are not able to carry out photosynthesis; their body is usually organised into a mycelium made from thread-like structures called hyphae, which contain many nuclei; some examples are single-celled; their cells have walls made of chitin; they feed by extracellular secretion of digestive enzymes onto food material and absorption of the organic products; this is known as saprotrophic nutrition; they may store carbohydrate as glycogen. Examples include Mucor, which has the typical fungal hyphal structure, and yeast, which is single-celled.
- Protoctists: these are microscopic single-celled organisms. Some, like Amoeba, that live in pond water, have features like an animal cell, while others, like Chlorella, have chloroplasts and are more like plants. A pathogenic example is Plasmodium, responsible for causing malaria.
- Bacteria: these are microscopic single-celled organisms; they have a cell wall, cell membrane, cytoplasm and plasmids; they lack a nucleus but contain a circular chromosome of DNA; some bacteria can carry out photosynthesis but most feed off other living or dead organisms. Examples include Lactobacillus bulgaricus, a rod-shaped bacterium used in the production of yoghurt from milk, and Pneumococcus, a spherical bacterium that acts as the pathogen causing pneumonia
- VIRSUSSmall Particles ( smaller than Bacteria )Parasitic : can only reproduce in living Organisms They only reproduce infect every type of living OrganismsThey have a wide variety of shapes and sizesNo Cellular structureHas protein coat Contains one type of Nucleic Acid ( RNA or DNA )Example: Tobacco Mosaic Virus / HIV Plants: Chlorella
- Common Pathogen
- PATHOGENS: Micro-organisms that causes Diseases