Biology 2
Osmosis and Plant Transport
Osmosis is the diffusion of water High Low
molecules from a dilute solution (high concentration concentration of
concentration of water) to a more e.g., bowl of water water molecules
concentrated solution (low concentration e.g., plant cell
of water) across a selectively permeable
membrane. Large solute
molecules unable to
When water moves into an animal cell, it pass through
stretches and gets bigger; if this continues membrane
it will burst – lysis.
Plant cell
Vacuole
Water can move Small water molecules
Cell
freely across the able to pass through
Cytoplasm Wall
gradient membrane
Nucleus Cell Membrane
Pressure created by
Increases the
Water moves Vacuole cell wall prevents too
Chloroplast turgor pressure
into cell expands much water entering
making it turgid
and causing lysis
Plasmolysis – too much
Plants use water for: water moves out of cell.
• Turgor
• Transpiration B5 Potato Cylinder & Visking tubing
• Transport of minerals Cylinders in water or weak sucrose
• Photosynthesis solution gain mass – water moved in.
Cylinders in strong sucrose solution
lose mass – water moved out.
Transpiration Sucrose solution that causes no
Transpiration is the evaporation of water from the spongy mesophyll cells change is the concentration equal to
followed by the diffusion of water through the air spaces and out of the stomata. the potato cell.
Transpiration stream is important because it provides: Visking tubing will gain mass as
• Leaves with a continuous supply of water (for photosynthesis). water has moved from high (outside)
• Transport of minerals from roots to plant. to low (inside) concentration.
• Support to plant cells.
• Water for transpiration.
B6 Potometer & Washing Line Method
Use a potometer to investigate factors affecting
the rate of water uptake.
Use washing line method to investigate factors
affecting the rate water loss.
Factor Effect on Why? How to change this factor
trans.
Surface area Decrease Smaller leaves contain less stoma Remove leaves
Temperature Increase High temp. increases rate of Use a heater
evaporation
Wind speed Increase High wind speed increases rate of Use a fan
evaporation
Humidity Decrease High humidity will reduce evaporation Clear plastic bag over
plant
Light Decrease Darkness causes stomata to close Use a lamp
intensity
, Circulatory System
Functions of the circulatory system:
− Transport – blood cells, glucose/amino acids, carbon dioxide, urea
− Protect – against disease – lymphocytes and phagocytes
Blood Component Function Structure
Red blood cells Carry oxygen • Biconcave – large surface area for
diffusion of oxygen
• Contains haemoglobin (contains iron)
to carry oxygen
• No nucleus – more space
White blood cells Defend against disease Lymphocytes make antibodies
Phagocytes engulf and digest
Plasma Transport blood cells, food, urea, CO2, hormones Yellow coloured liquid
Platelets Converts fibrinogen to fibrin – blood clotting/scab Cell fragments
Blood Vessels
Artery usually deoxygented
• Thick wall of muscle and elastic fibres to withstand high pressure. Expand and recoil
after each blood surge.
• Small lumen
• Away from the heart
Vein usually oxygenated
• Thin wall of muscle and elastic fibres. Blood doesn’t surge through veins.
• Large lumen for less friction – faster travel of blood.
• Has valves to prevent backflow.
Glucose and oxygen carried in oxygenated
• Low pressure
blood is used for respiration.
• Into the heart
Capillary
• Wall is one cell thick – allows
diffusion of substances between
blood and body cells.
• Large lumen relatively
• From artery to vein
Pulmonary
Vein
Pulmonary
Artery
Aorta
Right side pumps deoxygenated
Vena Cava blood to the lungs.
Left side pumps oxygenated blood
to the organs of the body.
Ventricular walls thicker than atrial walls –
Hepatic Vein Hepatic ventricles must pump blood further.
Artery Left ventricle wall is thicker than right one –
left ventricle pumps blood all around the body,
Hepatic
Portal Vein Mesenteric
whereas right only pumps to the lungs.
Artery
The heart is a unidirectional pump.
Double circulatory system – blood travels through
the heart twice in one circulation of the body.
Renal Effects of exercise
Renal Vein
Artery • Strengthens heart muscles
• Increases cardiac output
Osmosis and Plant Transport
Osmosis is the diffusion of water High Low
molecules from a dilute solution (high concentration concentration of
concentration of water) to a more e.g., bowl of water water molecules
concentrated solution (low concentration e.g., plant cell
of water) across a selectively permeable
membrane. Large solute
molecules unable to
When water moves into an animal cell, it pass through
stretches and gets bigger; if this continues membrane
it will burst – lysis.
Plant cell
Vacuole
Water can move Small water molecules
Cell
freely across the able to pass through
Cytoplasm Wall
gradient membrane
Nucleus Cell Membrane
Pressure created by
Increases the
Water moves Vacuole cell wall prevents too
Chloroplast turgor pressure
into cell expands much water entering
making it turgid
and causing lysis
Plasmolysis – too much
Plants use water for: water moves out of cell.
• Turgor
• Transpiration B5 Potato Cylinder & Visking tubing
• Transport of minerals Cylinders in water or weak sucrose
• Photosynthesis solution gain mass – water moved in.
Cylinders in strong sucrose solution
lose mass – water moved out.
Transpiration Sucrose solution that causes no
Transpiration is the evaporation of water from the spongy mesophyll cells change is the concentration equal to
followed by the diffusion of water through the air spaces and out of the stomata. the potato cell.
Transpiration stream is important because it provides: Visking tubing will gain mass as
• Leaves with a continuous supply of water (for photosynthesis). water has moved from high (outside)
• Transport of minerals from roots to plant. to low (inside) concentration.
• Support to plant cells.
• Water for transpiration.
B6 Potometer & Washing Line Method
Use a potometer to investigate factors affecting
the rate of water uptake.
Use washing line method to investigate factors
affecting the rate water loss.
Factor Effect on Why? How to change this factor
trans.
Surface area Decrease Smaller leaves contain less stoma Remove leaves
Temperature Increase High temp. increases rate of Use a heater
evaporation
Wind speed Increase High wind speed increases rate of Use a fan
evaporation
Humidity Decrease High humidity will reduce evaporation Clear plastic bag over
plant
Light Decrease Darkness causes stomata to close Use a lamp
intensity
, Circulatory System
Functions of the circulatory system:
− Transport – blood cells, glucose/amino acids, carbon dioxide, urea
− Protect – against disease – lymphocytes and phagocytes
Blood Component Function Structure
Red blood cells Carry oxygen • Biconcave – large surface area for
diffusion of oxygen
• Contains haemoglobin (contains iron)
to carry oxygen
• No nucleus – more space
White blood cells Defend against disease Lymphocytes make antibodies
Phagocytes engulf and digest
Plasma Transport blood cells, food, urea, CO2, hormones Yellow coloured liquid
Platelets Converts fibrinogen to fibrin – blood clotting/scab Cell fragments
Blood Vessels
Artery usually deoxygented
• Thick wall of muscle and elastic fibres to withstand high pressure. Expand and recoil
after each blood surge.
• Small lumen
• Away from the heart
Vein usually oxygenated
• Thin wall of muscle and elastic fibres. Blood doesn’t surge through veins.
• Large lumen for less friction – faster travel of blood.
• Has valves to prevent backflow.
Glucose and oxygen carried in oxygenated
• Low pressure
blood is used for respiration.
• Into the heart
Capillary
• Wall is one cell thick – allows
diffusion of substances between
blood and body cells.
• Large lumen relatively
• From artery to vein
Pulmonary
Vein
Pulmonary
Artery
Aorta
Right side pumps deoxygenated
Vena Cava blood to the lungs.
Left side pumps oxygenated blood
to the organs of the body.
Ventricular walls thicker than atrial walls –
Hepatic Vein Hepatic ventricles must pump blood further.
Artery Left ventricle wall is thicker than right one –
left ventricle pumps blood all around the body,
Hepatic
Portal Vein Mesenteric
whereas right only pumps to the lungs.
Artery
The heart is a unidirectional pump.
Double circulatory system – blood travels through
the heart twice in one circulation of the body.
Renal Effects of exercise
Renal Vein
Artery • Strengthens heart muscles
• Increases cardiac output
