CIE IGCSE Biology Revision Notes savemyexams.co.uk
2 ORGANISATION OF THE ORGANISM
YOUR NOTES
CONTENTS:
2.1 CELL STRUCTURE & ORGANISATION
2.2 SPECIALISED CELLS
2.3 LEVELS OF ORGANISATION
2.4 SIZE OF SPECIMENS
VIEW EXAM QUESTIONS
2.1 CELL STRUCTURE & ORGANISATION
Structures: Basics
• Cytoplasmis found inside the cell and contains all the other cell structures
• The large nucleus is surrounded by a nuclear membrane to separate it from the cytoplasm
• The cell membranesurrounds the cell
• The cell wallis made of cellulose and surrounds the cell membrane in plant cells
• Chloroplastsare organelles found in the cytoplasm that are packed with the pigment
chlorophylland so are green in colour
• Vacuolesare large vesicles that take up a large part of the interior of plant cells
An animal and plant cell as seen under a light microscope
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REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
2 ORGANISATION OF THE ORGANISM
YOUR NOTES
2.1 CELL STRUCTURE & ORGANISATION cont...
EXTENDED ONLY
Structures
Within the cytoplasm, the following organelles are visible in almost all cells except
prokaryotes when looking at higher magnification (ie using an electron microscope):
• Mitochondria(singular: mitochondrion) are organelles found throughout the
cytoplasm
• Ribosomesare tiny structures that can be free within the cytoplasm or attached to
a system of membranes within the cell known as Endoplasmic Reticulum
• Endoplasmic reticulum studded with ribosomes looks rough under the microscope;
this gives rise to its name of Rough Endoplasmic Reticulum
(often shortened to R .E.R.)
• Vesiclescan also be seen using a higher magnification – these are small circular
structures found moving throughout the cytoplasm
Structures in an animal cell visible under a light microscope
and an electron microscope
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REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
2 ORGANISATION OF THE ORGANISM
YOUR NOTES
2.1 CELL STRUCTURE & ORGANISATION cont...
EXTENDED ONLY cont...
Structures in a plant cell visible under a light microscope
and an electron microscope
Functions: Basics
STRUCTURE FUNCTION
NUCLEUS - CONTAINS GENETIC MATERIAL IN CHROMOSOMES WHICH
CONTROL HOW CELLS GROW AND WORK
- CONTROLS CELL DIVISION
CYTOPLASM - SUPPORTS CELL STRUCTURES
- SITE OF MANY CHEMICAL REACTIONS
- CONTAINS WATER AND MANY SOLUTES
CELL MEMBRANE - HOLDS THE CELL TOGETHER
- CONTROLS SUBSTANCES ENTERING AND LEAVING THE CELL
CELL WALL - GIVES THE CELL EXTRA SUPPORT AND DEFINES ITS SHAPE
CHLOROPLASTS - SITE OF PHOTOSYNTHESIS, PROVIDING FOOD FOR PLANTS
- THE CHLOROPHYLL PIGMENTS ABSORB LIGHT ENERGY NEEDED
FOR THE REACTION TO OCCUR
VACUOLE - CONTAINS CELL SAP
- USED FOR STORAGE OF CERTAIN MATERIALS
- ALSO HELPS SUPPORT THE SHAPE OF THE CELL
CIE IGCSE Biology Resources
© copyright Save My Exams Page 22
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
2 ORGANISATION OF THE ORGANISM
YOUR NOTES
CONTENTS:
2.1 CELL STRUCTURE & ORGANISATION
2.2 SPECIALISED CELLS
2.3 LEVELS OF ORGANISATION
2.4 SIZE OF SPECIMENS
VIEW EXAM QUESTIONS
2.1 CELL STRUCTURE & ORGANISATION
Structures: Basics
• Cytoplasmis found inside the cell and contains all the other cell structures
• The large nucleus is surrounded by a nuclear membrane to separate it from the cytoplasm
• The cell membranesurrounds the cell
• The cell wallis made of cellulose and surrounds the cell membrane in plant cells
• Chloroplastsare organelles found in the cytoplasm that are packed with the pigment
chlorophylland so are green in colour
• Vacuolesare large vesicles that take up a large part of the interior of plant cells
An animal and plant cell as seen under a light microscope
CIE IGCSE Biology Resources
© copyright Save My Exams Page 20
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
2 ORGANISATION OF THE ORGANISM
YOUR NOTES
2.1 CELL STRUCTURE & ORGANISATION cont...
EXTENDED ONLY
Structures
Within the cytoplasm, the following organelles are visible in almost all cells except
prokaryotes when looking at higher magnification (ie using an electron microscope):
• Mitochondria(singular: mitochondrion) are organelles found throughout the
cytoplasm
• Ribosomesare tiny structures that can be free within the cytoplasm or attached to
a system of membranes within the cell known as Endoplasmic Reticulum
• Endoplasmic reticulum studded with ribosomes looks rough under the microscope;
this gives rise to its name of Rough Endoplasmic Reticulum
(often shortened to R .E.R.)
• Vesiclescan also be seen using a higher magnification – these are small circular
structures found moving throughout the cytoplasm
Structures in an animal cell visible under a light microscope
and an electron microscope
CIE IGCSE Biology Resources
© copyright Save My Exams Page 21
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
2 ORGANISATION OF THE ORGANISM
YOUR NOTES
2.1 CELL STRUCTURE & ORGANISATION cont...
EXTENDED ONLY cont...
Structures in a plant cell visible under a light microscope
and an electron microscope
Functions: Basics
STRUCTURE FUNCTION
NUCLEUS - CONTAINS GENETIC MATERIAL IN CHROMOSOMES WHICH
CONTROL HOW CELLS GROW AND WORK
- CONTROLS CELL DIVISION
CYTOPLASM - SUPPORTS CELL STRUCTURES
- SITE OF MANY CHEMICAL REACTIONS
- CONTAINS WATER AND MANY SOLUTES
CELL MEMBRANE - HOLDS THE CELL TOGETHER
- CONTROLS SUBSTANCES ENTERING AND LEAVING THE CELL
CELL WALL - GIVES THE CELL EXTRA SUPPORT AND DEFINES ITS SHAPE
CHLOROPLASTS - SITE OF PHOTOSYNTHESIS, PROVIDING FOOD FOR PLANTS
- THE CHLOROPHYLL PIGMENTS ABSORB LIGHT ENERGY NEEDED
FOR THE REACTION TO OCCUR
VACUOLE - CONTAINS CELL SAP
- USED FOR STORAGE OF CERTAIN MATERIALS
- ALSO HELPS SUPPORT THE SHAPE OF THE CELL
CIE IGCSE Biology Resources
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REVISION NOTES TOPIC QUESTIONS PAST PAPERS
