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[BIOLOGY UNIT 2 REVISION NOTES]
EXAM 12th Jan 09 @ 9am
Cells
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All animals and plants are made of cells.
Animal cells and plant cells have features in common, such as a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes.
Plant cells also have a cell wall, and often have chloroplasts and a permanent vacuole. Cells may be specialised to carry out a particular function.
Dissolved substances pass into and out of cells by
. Water passes into and out of cells by
.
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This table shows the function of cells which animal and plant cells have in common.
Part
Function(s)
Nucleus
Contains genetic material; controls the activities of the cell.
Cytoplasm
Most chemical processes take place here; controlled by enzymes.
Cell Membrane
Controls the movement of substances into and out of the cell.
Mitochondria
Most energy is released by respiration here.
Ribosomes
Protein synthesis happens here – i.e. where proteins are made.
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This smaller table shows that plant cells also have extra parts.
Part
Function(s)
Cell Wall
Made of cellulose. Supports and strengthens the cell.
Chloroplasts
Contain chlorophyll, which absorbs light energy for photosynthesis.
Permanent Vacuole
Filled with cell sap (to help keep the cell turgid).
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Smallest living organisms are single cells – these can carry out all functions of life, from feeding and respiration to excretion and reproduction.
Most organisms are bigger and are made up of lots of cells, some of these become specialised to carry out particular jobs.
Good examples of specialist cells are sperm, eggs, red blood cells and nerve cells.
For example, a sperm cell’s function is to fertilise an egg cell:
Page 1 of 16
[BIOLOGY UNIT 2 REVISION NOTES]
EXAM 12th Jan 09 @ 9am
•
o The head contains genetic information and an enzyme
EXAM 12th Jan 09 @ 9am
Cells
s
u
f
f
i
d
s
i
s
o
m
s
o
•
i
•
•
o
•
All animals and plants are made of cells.
Animal cells and plant cells have features in common, such as a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes.
Plant cells also have a cell wall, and often have chloroplasts and a permanent vacuole. Cells may be specialised to carry out a particular function.
Dissolved substances pass into and out of cells by
. Water passes into and out of cells by
.
n
•
•
This table shows the function of cells which animal and plant cells have in common.
Part
Function(s)
Nucleus
Contains genetic material; controls the activities of the cell.
Cytoplasm
Most chemical processes take place here; controlled by enzymes.
Cell Membrane
Controls the movement of substances into and out of the cell.
Mitochondria
Most energy is released by respiration here.
Ribosomes
Protein synthesis happens here – i.e. where proteins are made.
•
This smaller table shows that plant cells also have extra parts.
Part
Function(s)
Cell Wall
Made of cellulose. Supports and strengthens the cell.
Chloroplasts
Contain chlorophyll, which absorbs light energy for photosynthesis.
Permanent Vacuole
Filled with cell sap (to help keep the cell turgid).
•
•
•
•
Smallest living organisms are single cells – these can carry out all functions of life, from feeding and respiration to excretion and reproduction.
Most organisms are bigger and are made up of lots of cells, some of these become specialised to carry out particular jobs.
Good examples of specialist cells are sperm, eggs, red blood cells and nerve cells.
For example, a sperm cell’s function is to fertilise an egg cell:
Page 1 of 16
[BIOLOGY UNIT 2 REVISION NOTES]
EXAM 12th Jan 09 @ 9am
•
o The head contains genetic information and an enzyme