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Cambridge IGCSE Biology
Extended Level
Classification
Plants, Bacteria, Viruses and Fungi
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You should be able to:
• List the main visible features of
monocotyledonous and dicotyledonous
flowering plants.
• List the main features of viruses, bacteria
and fungi, and their adaptations to the
environment
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Flowering plants are classified into
two groups:
Monocotyledonous plants
1 cotyledon
strap like leaves
parallel veins
flower parts divisible by 3
example: kaffir lily
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Flowering plants are classified into
two groups:
Dicotyledonous plants
2 cotyledons
broad leaves
branching veins
flower parts divisible by
4 or 5
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Comparing monocotyledons and
dicotyledons:
Feature
monocotyledon
dicotyledon
1
2
Leaf shape
strap like
broad
Vein pattern
parallel
branching
3
4 or 5
Kaffir lily
Hibiscus
Number of cotyledons
Flower parts divisible by:
Example
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Which plant is a monocotyledon
and which is a dicotyledon?
dicotyledon
monocotyledon
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Types of root systems
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Which one is a monocotyledonous plant?
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Bacteria are single celled
organisms
• Bacteria cells are about 1/1000th the size of animal or
plant cells.
cell membrane
cytoplasm
DNA
no nucleus,
DNA is one
long strand
kept in the
cytoplasm
cell wall
made of
peptidoglycans
slime capsule
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Structure of a bacteria
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Viruses are not classified as living
things as they are not made of cells
• Viruses are very small, approximately 100nm
across (1nm = 1/1000 000 of a mm)
10nm
RNA
proteins of the
virus coat
cross section of the human immunodeficiency virus (HIV)
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Viruses reproduce by invading
other cells
White blood cell (lymphocyte)
6. New viruses
leave the cell
1. Virus attaches
to cell membrane
2. Virus RNA
enters cell
3. DNA copy of
the RNA is made
5. Virus cores
are made in the
cytoplasm
4. Nucleus
makes copies of
the virus RNA
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The main body of a fungus is the
mycelium, which is made of hyphae
• Fungal cells have cell walls made of substances
such as chitin
mushroom
sporangium containing spores
spores produced here
hyphae of mushroom
mycelium
Mucor
growing on
moist bread
hyphae of Mucor
mycelium:
Secrete digestive
enzymes
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Now you should be able to:
• List the main visible features of
monocotyledonous and dicotyledonous
flowering plants.
• List the main features of viruses, bacteria
and fungi, and their adaptations to the
environment
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Cambridge IGCSE Biology
www.clickbiology.com
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