Organising Animals and Plants Flashcards
What are the 4 components of the blood?
Plasma, red blood cells, white blood cells and platelets
Describe the function of blood plasma, and give an example
To transport substances around the body
e.g. waste CO2 being carried to the lungs
What is the function of a red blood cell?
Transport O2 around the body and deliver to where it’s needed
Give 3 adaptations of red blood cells
- Bioconcave disc shaped, allowing for a larger surface area to volume ratio for diffusion
- Packed with a red pigment called haemoglobin which
binds to O2 - Have no nucleus to provide more space for
haemoglobin
Give the word equation for the bonding of oxygen and haemoglobin
Haemoglobin + Oxygen —– Oxyhaemoglobin
Describe the function of white blood cells
Form part of the body’s immune system to destroy pathogens
Describe the function of platelets
They help blood to clot around a wound and form scabs so that bacteria cannot enter the wound.
What are the pros and cons of donating blood?
Pros:
- Can replace blood lost in injury
- Some people are given platelets extracted from blood
to assist clotting
- Proteins extracted from blood can be used to make
antibodies
Cons:
- In a blood transfusion, the donor’s blood must be the
same type as the patient’s, or the patient’s immune
system will reject the donated blood and could possibly
die
- Many diseases can be transmitted through blood
Do arteries carry blood to or away from the heart?
Arteries carry blood away from the heart to the organs in the body ( art sounds like OUT)
Describe and explain the properties of arteries
They have a small lumen, and thick muscular walls to withstand the high pressure of the oxygenated blood that they’re transporting
Where is blood transported to after the arteries?
The capillaries
Describe what happens to blood at the capillaries
Substances such as glucose and oxygen diffuse from the blood into body cells, while CO2 diffuses from the body cells into the blood inside the capillaries
Describe and explain the properties of capillaries
They have thin walls that are one cell thick so that the diffusion pathway is short and quick, allowing substances to diffuse rapidly between the blood and body cells
Where does blood go after it’s travelled through the capillaries and body cells?
The veins
Do veins carry blood away or back towards the heart?
Back towards the heart ( ve-IN)
Describe the properties of Veins
They have thin walls and a large lumen because the blood is at a lower pressure
Describe the blood flow once the blood is in the veins
Blood is deoxygenated and at low pressure
What mechanism is in place to stop the backflow of blood once inside the veins?
Valves
What is the function of valves?
To prevent the backflow of blood
What is the benefit of a double circulatory system rather than a single one?
Blood travels through the heart twice, meaning it can travel faster around the body and to the body cells
What are the top chambers of the heart called?
The atria
What blood vessel brings deoxygenated blood from the body to the heart?
The Vena Cava
What blood vessel pumps deoxygenated blood to the lungs?
The Pulmonary artery
What blood vessel brings oxygenated blood from the lungs back to the heart?
The Pulmonary vein
What blood vessel pumps out oxygenated blood to the organs and body cells?
The aorta
Describe the pathway of blood in the human body
-Deoxygenated blood is brought into the heart via the Vena Cava, through the right atrium and down the right ventricle. The ventricle contracts and blood is pumped through the Pulmonary artery to the lungs. The blood collects oxygen and returns to the heart through the Pulmonary Vein. The blood then goes through the left atrium and ventricle, then is pumped out through the Aorta to the organs and body cells.
What are the purposes of valves in the heart?
They prevent backflow of the blood from the atria into the ventricles when the ventricles contract
Why does the left side of the heart have a thicker muscular wall than the right?
The left side of the heart pumps blood around the whole body, and therefore needs to provide more force, while the right side only pumps blood to the lungs
What are the Coronary arteries?
An important type of blood vessel that branch out of the aorta and spread into the heart muscle
- they supply the heart with oxygenated blood
What is the purpose of the Coronary Arteries?
To provide O2 to the muscle cells of the heart, which is used to provide energy for the heart to contract
What is the resting heart rate controlled by?
A pacemaker
What is an artificial pacemaker?
A small electrical device that corrects irregularities in the heart rate
Describe Coronary heart disease
The Coronary arteries that supply blood to the heart become narrow.
What is the most common cause of Coronary heart disease?
A buildup of fatty material on the lining of the vessels
What are the effects of Coronary heart disease?
Limits blood flow to the heart, therefore reducing the heart’s supply of O2, this can cause heart attacks and even death
What does a Stent do?
A stent is placed in the artery to keep it open and allow blood to flow through normally
What are the 2 main methods used to treat Coronary Heart disease?
Using stents and statins
What is the disadvantage of using stents
It doesn’t treat the underlying cause of the disease
What do statins do?
Statins are drugs which reduce the level of LDL cholesterol in the blood, slowing down the buildup of fatty deposits, and is proven to reduce the risk of Coronary heart disease
What is a disadvantage of using statins?
They have unwanted side effects, i.e. Liver problems
What are the effects of the heart containing valves that don’t fully open?
The heart has to pump harder to get blood through, this causes the heart to enlarge
What are the effects of leaky valves?
It causes fatigue
causes backflow of blood
How can faulty valves be treated?
- Can be replaced by mechanical valves, or one from an
animal
( Mechanical valves increase the risk of blood clots, so patients have to take anticlotting drugs, while animal valves don’t last long and need to be replaced)
What is heart failure?
A condition in which the heart can’t pump enough blood around the body
What ways are heart failure treated?
Patients are given a donated heart, or donated heart heart and lungs
Patients are given an artificial heart
What is a disadvantage of donating hearts?
There aren’t enough donated hearts for everyone in need
The patient must take drugs to stop the donated heart being rejected by their immune system
What are the disadvantages of using artificial hearts?
They increase the risk of blood clotting, and are only a short term solution for heart failure
Describe the process of inhaling and exhaling
The diaphragm and intercostal muscles contract, increasing the volume of the chest cavity, and oxygen rich air moves into the lungs, maintaining a steep concentration gradient with the blood so that O2 constantly diffuses into the bloodstream. Breathing out involves the relaxation of the diaphragm and intercostal muscles, decreasing the volume of the chest cavity. CO2 rich air is removed from the lungs so that a steep concentration gradient can be maintained allowing CO2 to continually diffuse out of the bloodstream to the air in the lungs
What are the purposes of alveoli?
They are the sites of gaseous exchange, and are where gases diffuse in and out of the bloodstream
What are the adaptations of the alveoli?
- Thin walls allowing for a short and rapid diffusion path
- Millions of alveoli mean that the lungs have a large
surface area - They have a good blood supply, once O2 diffuses into
the lungs it’s rapidly removed, ensuring a steep
concentration gradient
What is a key feature of the trachea?
It contains rings of cartilage to prevent it from collapsing when we inhale
How does breathing increase the rate of diffusion?
Breathing brings in fresh O2 into the alveoli and removes CO2, making the concentration gradient high for the gases, increasing the rate of diffusion
Name all leaf tissues
- Waxy cuticle
- Upper and lower epidermises
- Palisade mesophyll
- Spongy mesophyll
- Stomata and Guard cells
- Xylem and Phloem
- Meristem Tissue
Describe the function of the epidermal tissue and its adaptations
It protects the surface of the leaf and is transparent to allow light to pass through to the palisade cells below
Describe the function of the waxy cuticle
It is an oily material covering the upper epidermis, reducing the amount of evaporation so the leaf doesn’t dry out
Describe the function of the spongy mesophyll
Its located under the palisade mesophyll and contains air gaps to allow CO2 to diffuse from the stomata into the palisade cells above
Describe the function of the Stomata
Located under the lower epidermis, they are small pores which control the amount of water loss from the leaf, as well as letting CO2 out of the leaf and O2 in
What cells are on either side of each Stoma?
Guard cells
Describe the function and adaptation of the Palisade Mesophyll
Contains palisade cells which are packed with chloroplasts and located towards the top of the leaf to absorb the maximum amount of light
What are Meristem tissue and where are they found?
They are stem cells that can differentiate into different types of plant tissue, and are found in growing tips
(shoots and roots)
What is the purpose of Phloem tissue?
To transport dissolved sugars from the leaves to the rest of the plant (Translocation)
What is the purpose of Xylem tissue?
To transport water and dissolved mineral ions from the roots to the stem and leaves (Transpiration)
What is the function of Mg ions in plants?
Produces chlorophyll, and a lack of these causes yellow leaves and discoloration in the plant
What is the function of Nitrate ions in plants?
They produce proteins, and a lack of these stunts growth in the plant
What’s the purpose of root hair cells?
To absorb water
Describe how the adaptations of root hair cells aid its function
The root hair increases the cell’s surface area to increase the rate of absorption. It also doesn’t have chloroplasts as it’s underground
Describe the process of transpiration
Transpiration begins with the evaporation of water from cells inside the leaf, water vapour then diffuses through the air spaces in the spongy mesophyll and out of the leaf through the stomata. Now, water passes from the Xylem into the leaf to replace the lost water, and finally, water is drawn up by the root hair cells and up the Xylem vessels to the leaf. This whole process is the transpiration stream
What are the benefits of transpiration?
It brings water into the leaf, which is essential for photosynthesis. Transpiration also brings in dissolved mineral ions, (e.g magnesium) which play an important role in the plant. Evaporation from the leaf also cools it down, which is important in warm weather.
How does temperature affect the rate of transpiration?
At higher temperatures, the rate of evaporation is higher, so the rate of transpiration increases
How do dry conditions affect the rate of transpiration?
Transpiration occurs at a greater rate under dry conditions, where the air isn’t humid, as the rate of evaporation is greater under dry conditions.
How does the windiness affect the rate of transpiration?
The rate of transpiration increases in windy conditions, as the wind removes any water vapour, allowing more water to evaporate.
How does light intensity affect the rate of photosynthesis?
The rate of transpiration increases under greater light intensity as the rate of photosynthesis is greater, this means that the stomata now open to let CO2 enter and water vapour passes out of the leaf in turn.
What is each stoma surrounded by?
2 guard cells
Describe and explain 2 instances when the stomata would be closed
- When there is little water in the leaf, so the guard cells become flaccid as the lose water due to osmosis, reducing water loss through the stomata.
- However now the plant cannot photosynthesize
- They close at night time, where there is no light and photosynthesis cannot occur, so they don’t need to take in CO2
Describe and explain when the stomata would be open
- When there is a lot of water in the leaf, and the guard cells become turgid, causing the stomata to open and allow more CO2 into the leaf
Why are the stomata located on the underside of the leaf
It’s more shaded, so less water will evaporate, reducing water loss.
Describe the function and adaptations of root hair cells
They absorb water and mineral ions from the soil, to do this, they have a root hair which increases the surface area of the cell, increasing the rate of absorption and they have a lot of mitochondria to actively transport ions into the cell. They also don’t contain chloroplasts as they’re underground.
Describe the function and adaptations of xylem cells
The Xylem carries water and dissolved mineral ions from the roots to the leaves. Xylem cells have walls containing lignin, which provides support to the plant. The end walls between the cells are broken down, forming a long tube that the water and minerals can flow through easily.
Describe the function and adaptations of phloem cells
The Phloem transports dissolved sugars up and down the plant. The Phloem consists of 2 types of cells. Phloem vessel cells have no nucleus and limited cytoplasm, and the end walls have pores called sieve plates which allow dissolved sugars to move around the cell interior.
As the phloem vessel calls have limited cytoplasm, they haven’t got a lot of mitochondria, so each phloem vessel cell contains a companion cell connected by pores which provides energy to the phloem vessel cell
How does the phloem allow translocation
Cell sap can travel through pores between phloem cells
What is turgor pressure?
The pressure exerted by water on the cell wall
key adaptations of white blood cells
defend against blood cells
- produce antibodies to fight microorganisms
- produce antitoxins to neutralise any toxins produced by the microorganism
- have a nucleus
- can change shape to engulf unwelcome microorganisms
