Topoc 1 The nature And Variety Of life Flashcards
What characteristics do all living organisms share?
They move, respire, respond to their surroundings, they grow and develop, reproduce, excrete waste , require nutrition and they control their internal conditions
What common features do plants have?
There are multicellular organisms, their cells contain chloroplasts and are able to carry out photosynthesis, the cells store carbohydrates as starch or sucrose, their cells have cellulose cell walls
What common features do animals have?
They 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 coordination and they’re able to move from one place to another. They often store carbohydrates glycogen.
What common features do fungi have?
They don’t carry out photosynthesis; their body is usually organised into a mycelium made from threadlike structures called hyphae that contain many nuclei; some fungi are single celled; the store carbohydrate is glycogen
What is saprotrophic nutrition?
Fungi feed by extracellular secretion of digestive enzymes onto food material and absorption of the organic products
What’s a fungi cell wall is made of?
Chitin
What are common features of protoctists?
They microscopic single cell organisms some have features like animal cells whilst some have chloroplasts and more like plants
Examples of plants
Maize, peas or beans
Examples of animals
Mammals eg humans, insects eg house fly and mosquitoes
Examples of fungi
Mucor has typical structure and yeast is single celled
Examples of protoctists
Amoeba has animal cell like features, chlorella is more plantlike, a pathogenic example is plasmodium
What are the common features of bacteria?
They are microscopic single celled organisms they have a cell wall, cell membrane, cytoplasm, and plasmids. They don’t have a nucleus but contain a circular chromosome of DNA, some bacteria can carry out photosynthesis but most feed off of other living or dead organisms.
Examples of bacteria
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
What does the term pathogen mean?
Pathogens are organisms that cause disease
What can pathogens be?
Pathogens may include fungi, bacteria, protists or viruses
Describe common features of viruses
They are not living organisms; they are small particles then bacteria; they are parasitic and can reproduce only inside living cells. They infect every type of living organism. They have a wide variety of shapes and sizes. They have no cellular structure but I have a protein coat and contain one type of nuclear acid either DNA or RNA
Examples of viruses
The tobacco mosaic virus that causes discolouring of the leaves of tobacco plants by preventing the formation of chloroplasts , the influenza virus that causes flu and the HIV virus that causes AIDS
What organelles are in an animal cell?
Nucleus, ribosomes, cell membrane, mitochondria, cytoplasm
What structures are in plant cells?
Nucleus, ribosomes, cell membrane, cell wall, cytoplasm, mitochondria, chloroplast, permanent vacuole
Function off the mitochondria
Site of respiration and releases energy
Function of the nucleus
Controls the cells activities and contains DNA
Ribosomes function
Site of protein synthesis
Cytoplasm function
Site of chemical reactions
Cell membrane function
Controls what enters and exits cells
