B4 - organising animals and plants Flashcards
What is haemoglobin?
A chemical used to carry the oxygen in the blood.
What is oxyhaemoglobin?
The chemical haemoglobin combined with oxygen.
What is the white blood cells job?
To fight infection.
What are antitioxins?
Chemicals that are used to destroy the poisons produced by the bacteria.
What are platelets job?
their job is to produce a network of fibres to form blood clots
What are the 4 substances carried in blood plasma?
water, glucose, amino acids and carbon dioxide
What are the three different types of blood vessels?
arteries, veins and capillaries
What are the thickest type of blood vessels?
arteries
What are the thinnest blood vessels?
Capillaries
What are arteries job?
to carry blood AWAY from your heart and to the organs
What is the job of veins?
To carry blood away from the organs towards your heart
What is the job of capillaries?
Forms a huge network of tiny vessels linking the arteries and veins.
Why are capillaries so thin?
So substances such as oxygen and glucose can diffuse easily out of your blood and into your cells.
What side of the heart is thicker?
Left
Why is the left side of the heart thicker?
So it can pump blood further because it has to go around the whole body.
What are the large chambers in the heart called?
Ventricles
Why is the human system referred to as a double-system?
It has to pump blood to the body and back
Why do veins have valves?
To prevent the back flow of blood
What are the three stages in the cardiac cycle?
- Atria contracts
- Ventricles contracts
- Heart relaxes
What are biological valve replacements?
When atrioventricular valves become leaky so they are replaced by donated valves
Why are artificial hearts needed?
These are used when their heart fails but only temporarily. Used until a donor is found.
What is a stent?
Mesh structures that are inserted in coronary arteries to keep them open
What are statins?
Medication used to reduce blood cholesterol and slows down the formation of fatty deposits
What are artificial valve replacements?
When atrioventricular valves become leaky and are replaced by synthetically produced valves
What are artificial pacemakers?
They are used to correct irregularities in heart rate
What are heart transplants?
During heart failure a person receives a donated heart to continue to live
What is the definition for respiration?
2 chemical reactions in cells that release energy
What is the definition for ventilation (breathing)?
Pushing gases into and out of the lungs due to the diaphragm and intercostal muscles
What is the definition for gas exchange?
Diffusion of gases between blood, cells and the lungs
Contracting ____ intercostal muscles pull the ribs in and down, increasing thoracic pressure.
Internal
Contracting ___ intercostal muscles pull the ribs out and up, decreasing thoracic pressure.
External
What is the order of the tissues in the blade part of the leaf?
Upper epidermis
Palisade mesophyll
Spongy mesophyll
Lower epidermis
What’s the job of the upper epidermis?
Covered in wax for waterproofing
What’s the job of the lower epidermis?
Supports guard cells which open/ close stomata
What’s the job of the palisade mesophyll?
Contains chloroplasts which carry out photosynthesis
What’s the job of the spongy mesophyll?
Has air spaces and large surface area for diffusing gases easier.
What are the 3 tissues in the midrib of a leaf?
Xylem
Phloem
Meristems
What are meristems?
Unspecialised cells so they can differentiate into any cell
What’s the job of the xylem and phloem?
To transport tissues in plants
Where does translocation occur?
Phloem vessles
What do phloem vessels transport?
Dissolved sugars from leaves to the rest of the plant for respiration or storage.
Why do we use translocation?
So the sugars release energy for respiration or stored as starch.
Where does transpiration occur?
Xylem vessels
What are being transported in the xylem vessels?
Water and mineral ions are being transported from the roots to leaves
Why do we use transpiration streams and transpiration?
We use the water for photosynthesis and water also evaporated from stomata to draw more water in at the roots.
What is a transpiration stream?
The transport of water from the roots to the leaves in the xylem
What is transpiration?
The evaporation of water from the stomata of leaves which drives the transpiration stream.
What are factors affecting transpiration?
Temperature
Windspeed
Humidity
Light intensity (sunlight intensity)
