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biology > organising animals and plants-b4 > Flashcards

organising animals and plants-b4 Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

What is plasma?

A

Plasma is a pale straw coloured liquid that carries everything in the blood

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2
Q

What does plasma carry?

A

Rbc and wbc and platelets
nutrients like glucose and amino acids, these are the soluble products of digestion which are absorbed from the gut and taken to the cells of the body
carbon dioxide from the organs to the lungs
urea from the liver to the kidneys
hormones
proteins
antibodies and antitoxins produced by the white blood cells

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3
Q

What is the job of the red blood cells?

A

The job of the red blood cells is to carry oxygen from the lungs to all the cells in the body

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4
Q

What adaptations do red blood cells have which make them more efficient?

A
  • their shape is bioconcave disc this gives a large surface area for absorbing oxygen
  • they don’t have a nucleus- this allows more room to carry oxygen
  • they contain a red pigment called haemoglobin that binds to oxygen
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5
Q

What does haemoglobin do?

A

In the lungs, haemoglobin binds to oxygen to become oxyhaemoglobin. In body tissues, the reverse happens-oyxhaemoglobin splits up into haemoglobin and oxygen to release oxygen to the cells.

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6
Q

What do white blood cells do?

A 
Wbc defend against infection 
Some wbc(phagocytes) can change shape to engluf unwelcome microorganisms in a process called phagocytosis.
Other wbc(lypmocytes) produce antibodies to fight microorganisms as well as antitoxins to neutralise any toxins produced by the microorganisms 
Unlike red blood cells, they do have a nucleus
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7
Q

What are platelets?

A

They are small fragements of cells. They have no nucleus.
They help the blood to clot at a wound- to stop all your blood pouring out and to stop microorganisms getting in.
Lack of platelets can cause excessive bleeding and bruising

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8
Q

How does the clotting process work?

A

Blood clotting is a series of enzyme-controlled reactions that result in converting fibrinogen into fibrin. This produces a network of protein fibres that capture lots of red blood cells and more platelets to form a jelly like clot that stops you bleeding. The clot dries and hardens to form a scab. This protects the new skin as it grows and stops bacteria entering the body through the wound.

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9
Q

What are the three types of blood vessels?

A

arteries, capillaries and veins

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10
Q

Where do arteries carry blood?

A

Your arteries carry blood away from your heart to the organs of your body. This blood is usually bright red oxygenated blood.

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11
Q

What features do arteries have?

A

The heart pumps the blood out at high pressure so the artery walls are strong and elastic.
The walls are thick compared to the size of the hole down the middle(lumen)
They contain thick layers of muscle to make them strong, and elastic fibres to allow them to stretch and spring back.

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12
Q

Where do veins carry blood?

A

The veins carry blood away from the organs towards your heart. This blood is usually low in oxygen and therefore a deep purple-red colour.

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13
Q

Where do capillaries carry blood?

A

These are involved in the exchange of materials at the tissues

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14
Q

How do capillaries work?

A

Arteries branch into capillaries, they are really tiny.
They carry the blood really close to every cell in the body to exchange substances with them.
They have permeable walls, so substances can diffuse in and out
They supply food and oxygen, and take away wastes like CO2
Their walls are one cell thick. This increases the rate of diffusion by decreasing the distance over which it occurs.

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15
Q

What features do veins have?

A

Capillaries eventually join up to form veins
The blood is at lower pressure in the veins so the walls don’t need to be as thick as artery walls.
They have a bigger lumen than arteries to help blood flow despite the lower pressure
They also have valves to help keep the blood flowing in the right direction.

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16
Q

In a double circulatory system, what does the first system do?

A

One transport system carries blood from your heart to your lungs and back again. This allows oxygen and carbon dioxide to be exchanged with the air in the lungs.

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17
Q

In a double circulatory system what does the second system do?

A

The other transport system carries blood from your heart to all other organs of your body and back again

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18
Q

Why does a double circulatory system make our circulatory system efficient?

A

Fully oxygenated blood returns to the heart from the lungs, this blood can then be sent off to different parts of the body at high pressure, so more areas of your body can receive fully oxygenated blood quickly.

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19
Q

What does the heart do?

A

The heart is an organ that keeps the blood flowing around the body. The walls of the heart are mostly made of muscle tissue.

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20
Q

Why does the heart have valves?

A

The heart has valves to make sure that blood flows in the right direction- they prevent it flowing backwards

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21
Q

What are the four chambers of the heart?

A

right atrium, right ventricle, left atrium amd left ventricle

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22
Q

What happens in the heart during a heartbeat?(what happens to the blood)

A

Blood flows into the right atrium from the vena cava and blood flows into the right atrium from the pulmonary vein.
The right and left atrium contract, pushing the blood into the ventricles
The ventricles contract, forcing the blood into the pulmonary artery and aorta, and out of the heart.
The blood then flows to the organs through ateries and returns through veins. The atria fill again and the whole cycle starts over.

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23
Q

What is the noise of the heartbeat caused by?

A

It is the sound of valves of the heart closing to prevent the blood flowing backwards

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24
Q

Why is the muscle of the left ventricle thicker than the right ventricle?

A

This allows the left ventricle to develop the pressure needed to force the blood through the arterial system all over your body. The blood leaving the right ventricle moves through the pulmonary arteries to your lungs, where high pressure would damage the delicate capillary network where gas exchange takes place.

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25
Q

What do the coronary arteries do?

A

The heart also needs its own supply of oxygenated blood as it is a muscle. Arteries called the coronary arteries branch of the aorta and surround the heart, making sure that it gets all the oxygenated blood it needs.

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26
Q

What is your resting heart rate controlled by and how?

A

Your resting heart rate is controlled by a group of cells in the right atrium wall that act as a pacemaker.
These cells produce a small electric impulse which spreads to the surrounding muscle cells, causing them to contract.

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27
Q

What is an artificial pacemaker?

A

An artificial pacemaker is often used to control heartbeat if the natural pacemaker cells don’t work properly(e.g if the patient has an irregular heartbeat). It is a little device that;s implanted under the skin and has a wire going to the heart. It produces an electric current to keep the heart beating regularly.

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28
Q

What is cardiovascular disease?

A

Cardiovascular disease is a term used to describe diseases of the heart or blood vessels for example coronary heart disease.

29
Q

What is coronary heart disease?

A

Coronary heart disease is when the coronary arteries that supply the blood to the muscle of the heart get blocked by layers of fatty material building up.
This causes the arteries to become narrow, so blood flow is restricted and there is a lack of oxygen to the heart muscle- this can result in a heart attack.

30
Q

What are stents?

A

Stent are tubes that are inserted inside arteries

31
Q

What do stents do?

A

They keep the arteries open, making sure blood can pass through to the heart muscles. This keeps the person’s heart beating.

32
Q

What are the advantages of stents?

A

Stents are a way of lowering the risk of a heart attack in people with coronary heart disease. They are effective for a long time and the recovery time from the surgery is relatively quick

33
Q

What are the disadvantages of stents?

A

On the down side, there is a risk of complications during the operation(e.g a heart attack) and a risk of infection from surgery. There is also the risk of patients developing a blood clot near the stent- this is called thrombosis.

34
Q

What is cholesterol?

A

Cholesterol is an essential lipid that your own body produces and needs to function properly. However too much of a certain type of cholesterol can cause health problems.

35
Q

What happens when you have too much ‘bad’ cholesterol?

A

Having too much ‘bad’ cholesterol in the bloodstream can cause fatty deposits to form inside arteries, which can lead to coronary heart disease .

36
Q

What are statins?

A

Statins are drugs that can reduce the amount of ‘bad’ cholesterol present in the bloodstream. This slows down the rate of fatty deposits forming.

37
Q

What are the advantages of statins?

A

By reducing the amount of ‘bad’ cholorestol in the blood, statins can reduce the risk of strokes, coronary heart disease and heart attacks.
As well as reducing the amount of ‘bad’ cholorestol, statins can increase the amount of beneficial type of cholrestol(HDL) in your bloodstream. This type can remove bad cholrestol from the blood.
Some studies suggest that statins may also help prevent some other diseases.

38
Q

What are the disadvantages of statins?

A

Statins are a long term drug that must be taken regularly. There is the risk that someone could forget to take them.
Statins can sometimes cause negative side effects e.g headaches. Some of these side effects can be serious, e.g kidney failure, liver damage and memory loss.
The effect of statins isn’t isn’t instant, it takes time for their effect to kick in.

39
Q

What are artificial hearts?

A

Artificial hearts are mechanical devices that pump blood for a person whose own heart failed.
They are usually only used as a temporary fix, to keep a person’s heart alive until a donor heart can be found.

40
Q

What are the advantages of artificial hearts?

A

The main advantage of artificial hearts is that they are less likely to be rejected by the body’s immune system than a donor heart. This is because they are made from metals or plastics so the body doesn’t recognize them as ‘foreign’ and attack in the same way it does with living tissue.

41
Q

What are the disadvantages of artificial hearts?

A

Surgery to fit an artificial heart can lead to bleeding and infection. Also, artificial hearts don’t work as well as healthy natural ones- parts of the heart could wear out or the electrical monitor could fail. Blood doesn’t flow through artificial hearts as smoothly, which can cause blood clots and lead to strokes. The patient has to take drugs to thin their blood and make sure this doesn’t happen, which can cause problems with bleeding if they are hurt in a accident.

42
Q

Why do valves sometimes get weakened/damaged?

A

heart attacks, infection or old age

43
Q

What happens when a valve gets damaged?

A

The damage may cause the valve tissues to stiffen, so it wont’t open properly. Or a valve may become leaky, allowing blood to flow in both directions rather than just forward. This means that blood doesn’t circulate as efficiently as normal.

44
Q

How can docs fix damaged valves?

A

Severe valve damage can be treated by replacing the valve.
Replacement valves can be ones taken from humans or other mammals- these are biological valves. Or they can be man made- these are mechanical valves.
Replacing a valve is a much less drastic procedure than a whole heart transplant. But fitting artificial valves is still major surgery and there can still be problems with blood clots.

45
Q

What is an artificial pacemaker?

A

This is an electrical device used to correct irregularities in the heart rate, which is implanted into your chest.
Artificial pacemakers weigh between 20 and 50g and they are attached to your heart by two wires. The artificial pacemaker sends strong, regular electrical signals to your heart to stimulate it to beat properly.

46
Q

What is the thorax?

A

The thorax is the top part of your body. It is separated from the lower part of your body by the diaphragm

47
Q

What are lungs?

A

The lungs are big pink sponges and are protected by the rib cage. They are surrounded by the pleural membranes.

48
Q

How does air go from your trachea to your blood?

A

The air that you breathe in goes through the trachea. This splits into tubes called bronchi(each one is bronchus), one going to each lung. The bronchi split into progressively smaller tubes called bronchioles. The brioncholes finally end at small air sacs called alveoli where gas exchange takes place.

49
Q

Explain how gas exchange takes place in the lungs?

A

The lungs contain millions and millions of little air sacs called alveoli, surrounded by a network of blood capillaries. This is where gas exchange takes place.
The blood passing next to the alveoli has just returned to the lungs from the rest of the body, so it contains lots of carbon dioxide and very little oxygen. Oxygen diffuses out of the alveolus(high concentration) into the blood(low concentration). Carbon dioxide diffuses out of the blood(high concentration) into the alveolus(low conc) to be breathed out.

50
Q

Explain gas exchange in body cells?

A

When the blood reaches body cells, oxygen is released from the red blood cells(where there is a high conc) and diffuses into body cells(lower conc).
At the same time, carbon dioxide diffuses out of the body cells(high conc) into the blood(low conc). It is then carried back to the lungs.

51
Q

What are the organs in a plant?

A

Stems, roots and leaves

52
Q

What are examples of plant tissues?

A

Epidermal tissue, palisade mesophyll tissue, spongy mesophyll tissue, xylem and phloem, meristem tissue

53
Q

What is epidermal tissue?

A

This covers the whole plant. Epidermal tissue are covered with a waxy cuticle, which helps to reduce water loss by evaporation.

54
Q

What is palisade mesophyll tissue?

A

This is part of the leaf where most photosynthesis happens. The upper epidermis is transparent so that light can pass through it to palisade layer. The palisade layer has lots of chloroplasts. This means that they’re near the top of the leaf where they can get the most light.

55
Q

What is spongy mesophyll tissue?

A

This is also in the leaf, and contains big air spaces to allow gases to diffuse in and out of cells.

56
Q

What is xylem and phloem?

A

They transport things like water, mineral ions and food around the plant(through the roots, stems and leaves). The xylem and phloem form a network of vascular bundles, which deliver water and other nutrients to the entire leaf and take away glucose produced by photosynthesis. They also help support the structure.

57
Q

What is meristem tissue?

A

This is found at the growing tips of shoots and roots and is able to differentiate into lots of different types of plant cell, allowing the plant to grow.

58
Q

What tissues do leaves contain?

A

epidermal, mesopyhll, xylem and phloem tissues

59
Q

How are tissues of leaves adapted for efficient gas exchange?

A

The tissues of leaves are also adapted for efficient gas exchange. The lower epidermis is full of little holes called stomata, which let CO2 diffuse directly into the leaf. The opening and closing of stomata is controlled by guard cells in response to environmental conditions. The air spaces in the spongy mesophyll tissue increase the rate of diffusion of gases.

60
Q

info about phloem tubes?

A

They transport food substances(mainly dissolved sugars) made in the leaves to the rest of the plant for immediate use or for storage.

  • Made of columns of elongated living cells with small pores in the end walls to allow cell sap to flow through.
  • The transport goes in both directions
  • This process is called translocation
61
Q

info about xylem tubes?

A

They carry water and mineral ions from the roots to the stem and leaves.
Made of dead cells joined end to end with no end walls between them and a hole down the middle. They strengthen with a material called lignin.
The movement of water from the roots, through the xylem and out of leaves is called the transpiration stream.

62
Q

How does transpiration work?

A

Transpiration is caused by the evaporation and diffusion of water from a plant’s surface. Most transpiration happens at the leaves.
This evaporation creates a slight shortage of water in the leaf, and so more water is drawn up from the rest f the plant through the xylem vessels to replace it.
This in turn means more water is drawn up from the roots and so there is a constant transpiration stream of water through the plant.
Transpiration is just a side effect of the way leaves are adapted for photosynthesis. They have to have stomata in them so that gases can be exchanged easily. Because there’s more water inside the plant than in the air outside, the water escapes from the leaves through the stomata by diffusion.

63
Q

What four things are affected is transpiration rate affected by?

A

Light intensity, temperature, air flow and humidity

64
Q

How does light intensity affect transpiration?

A

The brighter the light, the greater the transpiration rate. Stomata begin to close as it gets darker. Photosynthesis can’t happen in the dark, so they don’t need to be open to let CO2 in. When the stomata are closed, very little water can escape.

65
Q

How does temperature affect transpiration?

A

The warmer it is, the faster transpiration happens.

When it’s warm the water particles have more energy to evaporate and diffuse out of the stomata.

66
Q

How does air flow affect transpiration?

A

The better the air flow around a leaf(e.g stronger wind), the greater the transpiration rate.
If air flow around a leaf is poor, the water vapour surrounds the leaf and doesn’t move away. This means there is a high concentration of water particles outside the leaf as well as inside it, so diffusion doesn’t happen as quickly.
If there’s good air flow, the water vapour is swept away, maintaining a low concentration of water in the air outside the leaf. Diffusion then happens quickly, from an area of higher concentration to an area of lower concentration.

67
Q

How does humidity affect the rate of transpiration?

A

The drier the air around the leaf, the faster transpiration happens. If the air is humid there is a lot of water in it already, so there is not much of a difference between the inside and the outside of the leaf.
Diffusion happens fastest if there is a really high concentration in one place, and a really low concentration in the other.

68
Q

Explain the experiment to estimate the rate of transpiration?

A

You can estimate the rate of transpiration by measuring the uptake of water by a plant. This is because you can assume that water uptake by the plant is directly related to water loss by the leaves(transpiration).
Set up the apparatus(potometer) and then record the starting position of the air bubble.
Start a stopwatch and record the distance moved by the bubble per unit time e.g per hour.
Keep the conditions constant throughout the experiment e.g temperature and air humidity.

69
Q

info about guard cells?

A

They have a kidney shape which opens and closes the stomata in a leaf.
When the plant has lots of water the guard cells fill with it and go plump and turgid. This makes the stomata open so gases can be exchanged for photosynthesis.
When the plant is short of water, the guard cells lose water and become flaccid, making the stomata close. This helps too much water vapour escaping.
Thin outer walls and thickened inner walls make the opening and closing work.
They’re also sensitive to light and close at night to save water without losing out on photosynthesis.
You usually find more stomata on the undersides of leaves than on top. The lower surface is shaded and cooler- so less water is lost through the stomata than if they were on the upper surface.
Guard cells are therefore adapted for gas exchange and controlling water loss within a leaf.

biology (8 decks)

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