Edexcel IGCSE and IB

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1.3 recall the term ‘pathogen’ and know that pathogens may be fungi, bacteria, protoctists or viruses.

Pathogenic cells include fungi, bacteria, protoctists, and viruses

[ibgcse]

1.2 describe the common features shared by organisms within the following main groups: plants, animals, fungi, bacteria, protoctists and viruses, and for each group describe examples and their features

Plants: 

multicellular

nucleus

contain chloroplasts

autotrophic (photosynthesise)

cellulose cell walls

cell membrane

ribosomes

mitochondria

vacuole

cytoplasm

store carbohydrates as starch or sucrose

e.g. flowering plants like cereal (maize) or peas

Animals:

multicellular

nucleus

no cell walls

ribosomes

mitochondria

cytoplasm

store carbohydrates as glycogen 

e.g. humans, mosquito

Fungi:

some are single-celled

body organised into a mycelium (made from thread-like structures called hyphae)

chitin cell walls

saprotrophic nutrition; secrete digestive enzymes onto food material and absorb organic matter

may store carbohydrates as glycogen 

e.g. mucor, yeast

Bacteria:

microscopic

single-celled

cell wall

cell membrane

cytoplasm

plasmids

no nucleus

circular chromosome of DNA

most feed off other living/dead organisms

e.g. Lactobacillus bulgaricus used in yoghurt production, Pneumococcus the pathogen that causes pneumonia

Protoctists:

microscopic

single-celled

e.g. Amoeba acts more like an animal cell, Chlorella more like a plant cell, pathogenic example is Plasmodium, which causes malaria

Viruses:

parasitic

can only reproduce in other living living

infect all living organisms

no cellular structure

protein coat

contain one type of nucleic acid (DNA or RNA)

e.g. Tobacco mosaic virus which discolours tobacco leaves, the influenza virus that causes the ‘flu', the HIV virus that causes AIDS 

[ibgcse]

1.1 Understand that living organisms share the following characteristics

Movement

Respiration

Sensitivity

Nutrition

Excretion

Reproduction

Growth

"MRS NERG"