1.2 - 1.4 Variety of Living Organisms

plants

multicellular, have chloroplasts meaning that they can photosynthesise, have cell walls which are made of cellulose and they store carbs as starch or sucrose

animals

multicellular, can’t photosynthesise, don’t have cells walls, most have some nervous coordination allowing them to adapt rapidly to their environment, they move around from one place to another and store carbs are glycogen

fungi

some are single celled, others have a body called mycelium which is made up of hyphae (thread like structures) which contains lots of nuclei, can’t photosynthesise, have cells walls made of chitin, most feed by saprotrophic nutrition and store carbs as glycogen

plant examples

flowering plants such as cereal (maize) or herbaceous legume (beans or peas)

animal examples

mammals (humans) or insects (houseflies and mosquitos)

fungi examples

singled celled fungus (yeast) and multicellular which has a mycelium and hyphae (mucor)

protoctists

eukaryotic, single celled and microscopic, some have chloroplasts and are similar to plant cells, others are more like animal cells

bacteria

prokaryotic, single cells and microscopic, don’t have a nucleus, have circular chromosomes of DNA, some can photosynthesise and most feed off other organisms

viruses

there are particles rather than cells and smaller than bacteria, they can only reproduce inside living cells, it is a parasite - it depends on another organism to grow and reproduce, they infect all types of living organisms, different shapes and sizes and don’t have a cellular structure but rather a protien coat around some genetic material (RNA or DNA)

protoctists examples

chlorella (plant cell like) and amoeba (animal cell like which lives in pond water)

bacteria examples

lactobacillus bulgaricus (makes milk go sour and turn into yoghurt and is rod shapes) and pneumococcus (spherical shape)

virus examples

influenza virus, tobacco mosaic virus (makes tobbacco leaves discolored by stopping them form producing chloroplasts) and HIV

pathogens

organisms that cause disease, they include some fungi, protoctists, bacterium and viruses even though they are not living

protoctist pathogen

plasmodium which causes malaria

bacteria pathogen

pneumococcus which causes pneumonia

viruses pathogen

influenza virus which causes the flu and HIV which causes AIDS

what is saprotrophic nutrition

feeding by extracellular secretion of enzymes onto food material and absorption of the organic products

differences between prokaryotic and eukaryotic cells

1. prokaryotic cells have circular DNA ,eukaryotic cells have linear DNA
2. prokaryotic cells don’t have a nuclei
3. prokaryotic DNA is stored in the cytoplasm, eukaryotic DNA is stored in the nucleus