B4 - Organising Animals And Plants 1️⃣✅ Flashcards
(37 cards)
What are the 2 main purposes of blood?
transport of materials (cells, 02, c02) and defence from pathogens
What is the function of an Artery?
To carry blood away from the heart to the organs of your body.
What are the properties of an Artery?
It has a thick layer of elastic fibres and muscle to prevent it from bursting under high pressure. It has a outer layer made up of tough fibres. It has no valves only close to the heart.
What is the function of a Capillary?
To exchange materials with cells e.g. glucose and 02
What are the properties of a Capillary?
It is one cell thick (very thin) to maximise exchange rate between cells.
What is the function of a Vein?
To carry into your heart, away from your organs
What are the properties of a Vein?
Because of the low pressure it has valves to stop backflow (so blood can only go in one direction). It has a large lumen (central cavity).
What are the properties of a Vein?
Because of the low pressure it has valves to stop backflow (so blood can only go in one direction). It has a large lumen (central cavity).
How are leaves adapted for photosynthesis?
They are thin so there is a shorter time for diffusion to take place because there is a shorter distance to travel. They have a large surface area to maximise light energy being taken in.
What is transpiration?
Transpiration is the evaporation of water through the stomata.
What is a transpiration stream?
A transpiration stream is the movement of water from the roos to the shoots in the xylem vessels.
What are some characteristics of the xylem cell?
Its dead - has thick walls so it doesn’t collapse under pressure - made of lignin - impermeable - has no cytoplasm - has no end walls
What does the xylem cell transport?
It transports water and dissolved mineral ions from the roots to the shoots (so the direction of flow is up).
What are some characteristics of the phloem cell?
Its alive - it has thinner walls than a xylem - made of cellulose - permeable - has a cytoplasm - perforated end walls (has holes in).
What does the phloem cell transport?
It transports sugars and amino acids everywhere around the plant (to the direction of flow is everywhere e.g. up and down)
When the heart muscle relaxes blood flows into the ___1.___ from the lungs and the ___2.___.
- atrium 2. body
The atria then contract, squeezing blood into the ____1.____.
- ventricle
When the ventricles contract blood is forced into the two ____1.____.
- arteries
The blood can’t flow backwards because of the ___1.___. Then the heart relaxes and the whole process starts again.
- valves
The aorta takes blood to the ___1.___.
- body
The pulmonary artery takes blood to the ___1.___.
- lungs
What are the two types of artificial valves?
Tissue valve and Mechanical valve
When would a artificial valve be needed?
When a persons valve is leaky so blood can’t flow properly (backwards in the wrong direction).
What are the differences between the two types of artificial valves?
Mechanical valves are very much artificial and tissue valves are made to mimic traditional human valves and are commonly transplanted from another human or animal.
