1(b) Variety of Living Organisms Flashcards
Plants
Students should know
Multicellular organism; thir cells contain chloroplasts and are ableto carry out photosynthesis; their ells have cellulose cell walls; they store carbohydrates as starch or sucrose. Examples include flowering plants, such as a cereal (maize), and a herbaceous legume (peas or beans)
Animals
Students should know
Multicellular organism; their cells do not contain chloroplasts and are not able to carry out photosyntheses; they have no cell walls; they usually have nervous co-ordination and are able to move from one place to another; they often store carbohydrates as glycogen. Examples include mammals, and insects.
Fungi
Students should know
Organisms unable to carry out photosyntheses; 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 out 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 is single-celled.
Protoctists
Students should know
Microscopic single-celled organism. Some have animal cell like features like Amoeba others are more like plants like Chlorella which contain chloroplasts. Plasmodium the pathogenic example for causing malaria.
Describe the common features shown by the prokaryotic organisms such as bacteria
Students should know
Microscopic single-celled organism; 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.
Understand the term pathogen and know that pathogens may include fungi, bacteria, protoctists or viruses
Students should know
Not living organisms. Smaller than bacteria; they are parasitic and can reproduce only inside living cells; they infect every type of living organism. They have no cellular structure but have a protein coat and contain one type of nucleic acid, either DNA or RNA. Examples include the tobacco mosaic virus that causes discolouring in tobacco plant leaves by preventing the formation of chloroplasts, the influenza virus that causes ‘flu’ and the HIV virus that causes AIDS.
Photosythesis
A chemical reaction in plants that uses light energy from the sun to convert carbon dioxide and water to glucose and oxygen.
Cytoplasm
The material inside a cell in which cellular structures are found. Site of many chemical reaction within the cell.
Ribosome
Organelle in a cell where protein synthesis occurs.
Protoctists
Microscopic, single-celled organism. Examples include Plasmodium and chlorella.
Viruses
Very small, non-living particles that can only reproduce inside living cells. Possess a protein coat and genetic material only.
Organ
Group of tissues with a common function
Plasmodium
A pathogenic example of a protoctist that causes malaria.
Cell wall
Strong, freely permeable structure around the outside of plant cells. Made of cellulose in plants and chitin in fungi.
HIV
An example of a virus that causes AIDS.
Hyphae
Thread-like structures, often containing many nuclei. Found in fungi.
Fungi
Organism that feed by saprotrophic nutrition. Have a body made up of mycelium containing many hyphae and cell walls containing chitin. Act as decomposers.
Mucor
An example of a multicellular fungus.
Prokaryote
An organism that does not have a nucleus. Mostly the bacteria kingdom.
