1 variety of living organisms, page 25-31 Flashcards
What are eukaryotes?
Cells that have a nucleus, all living organisms apart from bacteria.
What are the five major groups of living organisms?
- Plants.
- Animals.
- Fungi.
- Protoctists.
- Bacteria.
What are the features of plants?
- They are multicellular organisms.
- They contain chloroplasts so they are able to carry out photosynthesis.
- Their cell walls are made of cellulose.
- They store carbohydrates as starch which is often found inside plant cells and could be in cereal.
- They also store carbohydrates is sucrose which is transported around the plant and is sometimes stored in fruits and other plant organs.
What are the features of animals?
- They are multicellular organisms.
- Our cells do not contain chloroplasts so we gain our nutrition from eating other organisms.
- They have no cell wall so they can change shape.
- They have nervous coordination and are able to move from one place to another.
- We store carbohydrates as glycogen.
What is glycogen?
It is how homo-sapiens store carbohydrates. It can be found in the liver.
What are the features of fungi?
- They are not able to carry out photosynthesis.
- Their body is usually organised into mycelium made from thread like structures called hyphae which contain many nuclei.
- Some are single cellular but some are also a multicellular.
- They’re cell walls are made of chitin.
- They feed by extracellular secretion of digestive enzymes on to food material and absorption of the organic products which is known as saprotrophic nutrition.
- They store carbohydrates as glycogen.
- Mucor is an example, and so is yeast.
What is hyphae?
Thread like filaments of cells found in fungi.
How does mould infect something?
- When a Spore of Mucor lands on a structure.
- A hypha grows out from it.
- This hypha grows and it branches out again and again until the mycelium covers the surface of the food.
- The hyphae secrete digestive enzymes which break it down into soluble substances, like sugar, for the mould to absorb.
What are protoctists?
A mixed group of eukaryotic organisms that are not plants, animals nor fungi. They are mostly unicellular species.
What are the features of protists?
- They are microscopic single-celled organs.
- Some, like amoeba that live in pond water have features much like an animal cell.
- However, others like Chlorella have chloroplasts and are more like plants.
- A pathogenic examples plasmodium, responsible for causing malaria.
What are prokaryotic cells?
They are organism made of simpler cells; which have no nucleus, mitochondria or chloroplasts.
What are the features of bacteria?
- Microscopic single celled organisms.
- They have a cell wall, cell membrane, cytoplasm and plasmids
- They have a circular chromosome of DNA but lacks a nucleus
- Some bacteria can carry out photosynthesis but most feed off other living or dead organisms.
What are some examples of bacteria?
- Lactobacillus bulgaricus, which is a bacterium used in the production of yoghurt from milk.
- Pneumococcus which is a spherical bacterium that acts as the pathogen causing pneumonia.
What is a pathogen?
An organism that causes disease, e.g some bacteria.
What are examples of pathogens?
- Fungi.
- Bacteria.
- Protoctists.
- Viruses.
