B4 - organising animals and plants. Flashcards
What are the adaptations of a red blood cell?
No nucleus to carry more oxygen, biconcave shape ( large surface area).
What are the components of blood and what are their jobs?
Red blood cells: carry oxygen around body
White blood cells: make antibodies to fight diseases
Platelets: to clot the blood
Plasma: carry’s dissolved food and waste products.
What direction do arteries carry blood?
Away from the heart
What is the structure of an artery?
-thick muscular walls
-elastic tissue in walls
-relatively small lumen
-no valves
What direction do veins carry the blood?
Into the heart
What is the lumen?
The central cavity of the vein/artery
What is the structure of veins?
-Thin muscular walls
-not very elastic tissue in walls
-large lumen
-valves to prevent back flow
Does blood flow faster in veins or arteries?
A lot faster in arteries and under more pressure.
What happens in the capillaries?
The materials the blood is carrying diffuses into the body
What is the structure of capillaries?
-no muscles ( walls one cell thick )
-small lumen ( just enough to fit 1 red blood cell through )
-no elastic tissue in walls
-no valves
What is the largest artery in the body and where is it found?
The aorta and it’s found carrying blood away from the heart.
Where is the largest vein found and what is it called?
The vena cava is found carrying deoxygenated blood to the heart
Why can the circulatory system be called the double circulatory system?
As they are two main loop on to the lungs and back and one to the rest of the body and back
What are the top 2 and bottom 2 chambers called?
The top 2 are atria ( 2 atrium) and the bottom 2 are ventricles (A.V)
What are the names of the 2 valves in the heart and where are they found?
The atrio-ventricular valve is found both sides of the heart between the atria and ventricles and prevents back flow in atria.
The semilunar valve is found at the base of the pulmonary artery and aorta and prevents back flow into ventricles.
Which blood vessel carry’s oxygenated blood from the heart to the body?
Aorta
Which blood vessel carry’s deoxygenated blood from the heart to the lungs?
Pulmonary artery.
Does the left or right ventricle pump blood all the way around the body?
Left
Pace maker cells are found in which chamber of the heart?
Right atrium
Do artery’s or veins carry blood away from the heart?
Arteries
Which arteries supply blood to the heart muscle?
Coronary arteries
What 3 things make up the cardiovascular system?
Blood, blood vessels and heart
What can coronary heart disease cause?
Fatty material to build up and for the lumen of the coronary arteries to get smaller.
What are some treatments for coronary heart disease?
Stents and statins
What are some pros and cons of stents.
Pros: immediate effect, surgery is quick and last a long time
Cons: surgery has risks and risk of blood clot
How do statins help treat coronary heart disease?
They increase the amount of HDL cholesterol in the blood and decrease the amount of LDL cholesterol in the blood.
What are the advantages and disadvantages of statins?
Pros: lower risk of other diseases and no surgery
Cons: pills every day, months to see effects and risks of kidney failure and headaches
What are 2 problems that could be cause by faulty valves ?
Blood passing backwards through valves and not enough blood can pass through valves.
Why is a mechanical heart less risky than a biological one?
As a biological one may be rejected by the immune system .
What is an artificial pacemaker?
A small box that sits just below the collar bone that when the heart isn’t functioning correctly will send a small electrical pulse to the heart to make it work properly.
Which substance inside red blood cells does oxygen bind to?
Haemoglobin
What are the bronchioles?
Tiny branches of the bronchi which carry air to the alveoli
What do the intercostal muscles do?
They raise and lower the rib cage
What is the diaphragm?
It is a sheet of muscle at the base of the thorax that allows us to breathe.
What adaptations do alveoli have to make gas exchange more efficient?
1)large surface area
2)walls only 1 cell thick
3)very close to blood capillaries to maintain conc gradient
4)moist walls to absorb gases
Describe what happens when someone breathes in.
1)intercostal muscles relax and move up
2)diaphragm contracts and moves down
3)pressure in chest cavity increases
4)air rushes into lungs
(Opposite for breathing out)
What is a meristem tissue and where is it found?
Meristem tissue is made up of plant stem cells. It’s found in the growing parts of the plant such as the tips of roots and shoots.
How are stomata adapted to conserve water?
The stomata are closes at night when photosynthesis isn’t taking place, there is a waxy cuticle to prevent water evaporating and the stomata only open for short amounts of time.
If there is plenty of water in the leaf, the guard cell becomes …….. , which ………. The stomata. This allows carbon dioxide to ………… the leaf, but also allows water to escape.
If there is plenty of water in the leaf, the guard cell becomes “turgid” , which “opens” The stomata. This allows carbon dioxide to “enter” the leaf, but also allows water to escape.
What adaptation allows the maximum amount of light to get to the palisade mesophyll cells ?
The upper epidermis is transparent so light can pass through it.
In which cells do most of the photosynthesis take place?
Palisade mesophyll cells
What layer on a leaf is found above the lower epidermis?
Spongy mesophyll layer
What do you call the movement of cell sap up and down the plant?
Translocation
What do phloem cells have in there wall to allow sap to travel through?
Pores
What do xylem transport?
Water and dissolved mineral ions
What substance are xylem cells reinforced with?
Lignin
What is transpiration?
The evaporation of water from the leaves
What happens to the transpiration rate if the temperature increases and why?
It increases as the rate of evaporation increases
What are the 4 things that can affect the rate of transpiration?
Temperature, light, humidity and wind
What happens to transpiration rate if light intensity increases and why?
It increases as when the stomata open to let more carbon dioxide in for photosynthesis more water evaporates
What happens to the rate of transpiration if wind increases and why?
It increases as the wind blows away any water vapour as soon as it evaporates out of the leaf meaning the consentration gradient is very steep
What happens to the rate of diffusion when humidity increases and why?
It decreases as there so much water outside the plant that the consentration gradient is almost flat.
