Variety of life


Variety of life - Prototists

These are microscopic single-called 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. Anpathogenic example is Plasmodium, responsible for causing malaria.

Picture of Euglena - which is unicellular

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Variety of life - 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, contain many nuclei; some examples are single-called; they have cell walls made of chitin; they feed by extra cellular 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.

Mould grows better if it has some water but not to much
Saprotrophic nutrition:
•5 ways to make food not go off: Extra-cellular secretion of digestive
Freeze (bread) — Mucor means bread Mould. enzymes onto food material and
Frigde (milk). and absorption of the organic products
Put lemon juice on it (salad). ;this is known as saprotrophic nutrition.
Cook it (chicken)
Store in a dry place (soup)
Eat it (chocolate)

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Variety of life - 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 Bulgarians, a rod-shaped bacterium used in the production of yoghurt from milk, and Pneumococcus, a spherical bacterium that acts as the pathogen causing pneumonia

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Variety of life - Viruses

These are small particles, smaller than bacteria; they are parasitic and can reproduce oil inside living cells; they infact every type of living organism. They have a wide variety of shapes and sizes; they have no cellular structure but have a protein coat and contain one type of nuclei can acid, either DNA or RNA. Examples include the tabacco mosaic virus that causes discolouring of the leaves of tabacco plants by preventing the formation of chloroplasts, the influnza virus that causes 'flu' and the HIV virus that causes AIDS.

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Variety of life - Pathogens

Pathogens may be fungi, bacteria, protoctist or viruses. Know examples of diseases caused by each: fungi - athletes foot, bacteria - Pneumonia, protoctist - malaria, virus - 'flu and AIDS'

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