IGCSE - BIOLOGY COMPLETE SYLLABUS
B1 Characteristics of living organisms
1. Describe the characteristics of living organisms by defining the terms:
○ Movement: an action by an organism causing a change of position or place
○ Respiration: the chemical reactions in cells that break down nutrient molecules
and release energy
○ Sensitivity: the ability to detect and respond to changes in the environment
○ Growth: a permanent increase in size
○ Reproduction: the processes that make more of the same kind of organism
○ Excretion: removal from organisms of toxic materials and substances in excess
of requirements
○ Nutrition: taking in of materials for energy, growth and development
B2 Cells
B2.1 Cell structure
1. State that living organisms are made of cells
2. Describe and compare the structure of a plant cell with an animal cell,
as seen under a light microscope, limited to cell wall, nucleus,
cytoplasm, chloroplasts, vacuoles and location of the cell membrane
○ All typical cells have:
■ Cell membrane: differentially or partially permeable to allow certain
substances to enter and leave the cell.
■ Cytoplasm: where chemical reactions take place
■ Nucleus: contains DNA and controls the cell
■ Mitochondria: organelle where aerobic respiration happens
■ Ribosome: makes protein and can be found floating within the
cytoplasm
*A typical animal cell (e.g. the liver cell) has all of the above
○ Only plant cells have:
○ Vacuole: stores food & water & helps to maintain the shape of cell
○ Cell wall: rigid to keep shape of cell
, ○ Chloroplasts: contain chlorophyll, which absorbs light energy for
photosynthesis
3. State the functions of the structures seen under the light microscope
in the plant cell and in the animal cell
4. Relate the structure of the following to their functions:
Structure Function Adaptation(s)
, ciliated Movement of mucus - Tiny hairs called cilia on the surface beat
cells in the trachea and to move mucus and trapped particles up
bronchi to the throat
root hair Absorb mineral ions - Root hair increases surface area of cell to
cells and water from soil ensure maximum absorption
- Elongated shape for more surface area
- Walls are thin to ensure water moves
through quickly
palisade Photosynthesize - Column-shaped to maximize absorption of
mesophyll sunlight and fit as many in a layer under the
cells upper epidermis of the leaf as possible
- Many chloroplasts
red blood Transport of oxygen - Biconcave disc shape
cells - No nucleus
- Flexible
- Contain haemoglobin (joins with oxygen to
transport it)
sperm and Reproduction - The acrosome in the head contain enzymes
egg cells to that it can penetrate the egg easily
- Head contains the genetic material for
fertilisation in a haploid nucleus
- Middle piece packed with mitochondria to
release energy needed to swim and fertilise
the egg
- Long, thin tail to enable it to swim
5. Calculate magnification and size of biological specimens using
millimetres as units
○ Using millimetres as units:
● Magnification is calculated using the following equation:
, B2.2 Movement in and out of cells
1. Define diffusion as the net movement of particles from a region of
their higher concentration to a region of their lower concentration
down a concentration gradient, as a result of their random movement
2. State that substances move into and out of cells by diffusion through
the cell membrane
3. State that water diffuses through partially permeable membranes by
osmosis
4. Define osmosis as the net movement of water molecules from a
region of higher water potential (dilute solution) to a region of lower
water potential (concentrated solution), through a partially permeable
membrane
5. State that water moves in and out of cells by osmosis through the cell
membrane
6. Investigate and describe the effects on plant tissues of immersing
them in solutions of different concentrations
○ The most common osmosis practical involves cutting cylinders of potato
and placing them into distilled water and sucrose solutions of increasing
concentration
○ The potato cylinders are weighed before placing into the solutions
○ They are left in the solutions for 20 – 30 minutes and then removed, dried to
remove excess liquid and reweighed
○ The potato cylinder in the distilled water will have increased its mass the
most as there is a greater concentration gradient in this tube between the
distilled water (high water concentration) and the potato cells (lower water
concentration)
○ This means more water molecules will move into the potato cells by
osmosis, pushing the cell membrane against the cell wall and so increasing
the turgor pressure in the cells which makes them turgid – the potato
cylinders will feel hard
B1 Characteristics of living organisms
1. Describe the characteristics of living organisms by defining the terms:
○ Movement: an action by an organism causing a change of position or place
○ Respiration: the chemical reactions in cells that break down nutrient molecules
and release energy
○ Sensitivity: the ability to detect and respond to changes in the environment
○ Growth: a permanent increase in size
○ Reproduction: the processes that make more of the same kind of organism
○ Excretion: removal from organisms of toxic materials and substances in excess
of requirements
○ Nutrition: taking in of materials for energy, growth and development
B2 Cells
B2.1 Cell structure
1. State that living organisms are made of cells
2. Describe and compare the structure of a plant cell with an animal cell,
as seen under a light microscope, limited to cell wall, nucleus,
cytoplasm, chloroplasts, vacuoles and location of the cell membrane
○ All typical cells have:
■ Cell membrane: differentially or partially permeable to allow certain
substances to enter and leave the cell.
■ Cytoplasm: where chemical reactions take place
■ Nucleus: contains DNA and controls the cell
■ Mitochondria: organelle where aerobic respiration happens
■ Ribosome: makes protein and can be found floating within the
cytoplasm
*A typical animal cell (e.g. the liver cell) has all of the above
○ Only plant cells have:
○ Vacuole: stores food & water & helps to maintain the shape of cell
○ Cell wall: rigid to keep shape of cell
, ○ Chloroplasts: contain chlorophyll, which absorbs light energy for
photosynthesis
3. State the functions of the structures seen under the light microscope
in the plant cell and in the animal cell
4. Relate the structure of the following to their functions:
Structure Function Adaptation(s)
, ciliated Movement of mucus - Tiny hairs called cilia on the surface beat
cells in the trachea and to move mucus and trapped particles up
bronchi to the throat
root hair Absorb mineral ions - Root hair increases surface area of cell to
cells and water from soil ensure maximum absorption
- Elongated shape for more surface area
- Walls are thin to ensure water moves
through quickly
palisade Photosynthesize - Column-shaped to maximize absorption of
mesophyll sunlight and fit as many in a layer under the
cells upper epidermis of the leaf as possible
- Many chloroplasts
red blood Transport of oxygen - Biconcave disc shape
cells - No nucleus
- Flexible
- Contain haemoglobin (joins with oxygen to
transport it)
sperm and Reproduction - The acrosome in the head contain enzymes
egg cells to that it can penetrate the egg easily
- Head contains the genetic material for
fertilisation in a haploid nucleus
- Middle piece packed with mitochondria to
release energy needed to swim and fertilise
the egg
- Long, thin tail to enable it to swim
5. Calculate magnification and size of biological specimens using
millimetres as units
○ Using millimetres as units:
● Magnification is calculated using the following equation:
, B2.2 Movement in and out of cells
1. Define diffusion as the net movement of particles from a region of
their higher concentration to a region of their lower concentration
down a concentration gradient, as a result of their random movement
2. State that substances move into and out of cells by diffusion through
the cell membrane
3. State that water diffuses through partially permeable membranes by
osmosis
4. Define osmosis as the net movement of water molecules from a
region of higher water potential (dilute solution) to a region of lower
water potential (concentrated solution), through a partially permeable
membrane
5. State that water moves in and out of cells by osmosis through the cell
membrane
6. Investigate and describe the effects on plant tissues of immersing
them in solutions of different concentrations
○ The most common osmosis practical involves cutting cylinders of potato
and placing them into distilled water and sucrose solutions of increasing
concentration
○ The potato cylinders are weighed before placing into the solutions
○ They are left in the solutions for 20 – 30 minutes and then removed, dried to
remove excess liquid and reweighed
○ The potato cylinder in the distilled water will have increased its mass the
most as there is a greater concentration gradient in this tube between the
distilled water (high water concentration) and the potato cells (lower water
concentration)
○ This means more water molecules will move into the potato cells by
osmosis, pushing the cell membrane against the cell wall and so increasing
the turgor pressure in the cells which makes them turgid – the potato
cylinders will feel hard
