Transcript Edexcel AS Level Biology

Cell Biology
Cambridge IGCSE Biology
Extended Level
Cells
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You should be able to:
• Identify and describe the structure of plant cells and animal cells,
and describe the functions of their parts.
• Describe the difference between animal cells and plant cells.
• Explain the structure and function of specialised cells: red blood cell,
muscle cells, ciliated cells, xylem vessels and root hair cells.
• Define the terms tissue, organ and organ systems, with examples.
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A section through a liver cell (animal
cell):
cell membrane
controls what
enters and
leaves the cell
cytoplasm
metabolic
(chemical)
reactions
occur here
nucleus
contains the
DNA and so
controls the cell
DNA
contains the
coded
instructions to
make proteins
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Section through a palisade cell of a leaf
(plant cell)
chloroplast
cell membrane
nucleus
large sap vacuole
cellulose cell wall
cytoplasm
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You should be able to:
• Identify and describe the structure of plant cells and animal cells,
and describe the functions of their parts.
• Describe the difference between animal cells and plant cells.
• Explain the structure and function of specialised cells: red blood cell,
muscle cells, ciliated cells, xylem vessels and root hair cells.
• Define the terms tissue, organ and organ systems, with examples.
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Comparing animal and plant cells
Found in both animal
and plant cells
Found only in plant
cells
cell membrane
cellulose cell wall
nucleus
large sap vacuole
cytoplasm
chloroplast
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You should be able to:
• Identify and describe the structure of plant cells and animal cells,
and describe the functions of their parts.
• Describe the difference between animal cells and plant cells.
• Explain the structure and function of specialised cells: red blood cell,
muscle cells, ciliated cells, xylem vessels and root hair cells.
• Define the terms tissue, organ and organ systems, with examples.
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Red blood cells transport oxygen
cell surface membrane
cytoplasm contains
no nucleus
allows more room for
haemoglobin
cytoplasm contains
haemoglobin
haemoglobin is a
protein which carries
the oxygen molecules
bi-concave disc shape
increases surface area
over which absorption of
oxygen can occur
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Muscle cells contract and enable
movement of the body
muscle
Muscle cells have
many nuclei
cell surface membrane
nucleus
The strands of protein
slide over each other
making the muscle cell
(fibre) shorter and causing
the muscle to contract
protein strands
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Ciliated cells move bacteria and dust
away from the lungs
cilia
Cilia are small extensions of
the cell. They beat rhythmically
to sweep mucus, which has
trapped bacteria and dust,
away from the lungs
nucleus
magnification X3000
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Xylem vessels transport water and
minerals up the plant
xylem vessels are continuous tubes
xylem vessel
no cytoplasm
hollow: allows for
continuous flow of
water and dissolved
mineral ions
lignin
water-proof and strong;
helps support the plant
cross-section
longitudinal section
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Root hair cells absorb minerals and
water from the soil
Cross-section of a root hair cell
cytoplasm
contains no
chloroplasts as no
photosynthesis is
needed
cell membrane semi-permeable, so will
allow water and mineral
ions into the cell
root hair
increases surface area for absorption
of water and mineral ions
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You should be able to:
• Identify and describe the structure of plant cells and animal cells,
and describe the functions of their parts.
• Describe the difference between animal cells and plant cells.
• Explain the structure and function of specialised cells: red blood cell,
muscle cells, ciliated cells, xylem vessels and root hair cells.
• Define the terms tissue, organ and organ systems, with examples.
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A tissue is a group of cells of similar
structure that perform a shared function
Tissues found in the leaf
Animal tissues:
muscle tissue
upper epidermal
tissue
palisade mesophyll
tissue
spongy mesophyll
tissue
nervous tissue
lower epidermal
tissue
Cross-section of a leaf
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An organ is a structure made of a
group of tissues working together to
perform specific functions
heart
stomach
lungs
liver
brain
kidneys
Plant organs include the stem and the leaves
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An organ system is a group of organs that
coordinate to perform related functions
lymphatic
system
digestive
system
respiratory
system
reproductive
system
excretory
system
skeletal
system
muscular
system
endocrine
system
nervous
system
circulatory
system
In plants the shoot is an organ system consisting of leaves and the stem
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Levels of organisation
cell
nerve cell
smallest
tissue
nervous
tissue
organ
organ
systems
brain
nervous
system
organism
Homo sapiens
largest
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Now you should be able to:
• Identify and describe the structure of plant cells and
animal cells, and describe the functions of their parts.
• Describe the difference between animal cells and plant
cells.
• Explain the structure and function of specialised cells:
red blood cell, muscle cells, ciliated cells, xylem vessels
and root hair cells.
• Define the terms tissue, organ and organ systems, with
examples.
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Now write down everything you
remember from the presentation
• Don’t refer to your text book straight away,
see what information you have retained.
• Check the notes you have made by
checking your book.
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