Organisation Flashcards
1
Q
definitions of:
a) A tissue
b) An organ.
c) Organ system
A
- A tissue is a group of cells with a similar structure and function.
- Organ: An organ is a group of tissues working together for a specific function.
- A group of organs that work together to form organisms.
2
Q
Why can’t carbohydrates, fats and proteins be digested into the bloodstream?
A
- Because all of them are large molecules, so they are too large to be absorbed into the bloodstream, so they have to be digested.
3
Q
What happens during digestion?
A
- Large food molecules are broken down into small food molecules by enzymes.
- The small molecules can then be absorbed into the bloodstream.
4
Q
Describe the order of the organs the food go to during digestion.
A
The food goes to the mouth first, then the
5
Q
Explain the function of the mouth / saliva in the first step of digestion.
A
- The food is first chewed in the mouth.
-Amylase produced by the salivary glands digests the large starch molecules into smaller sugar molecules.
6
Q
State the function of the stomach in digestion.
A
- The digestion of proteins begins in the stomach.
- The stomach also contains HCL which helps the enzymes digest the protein.
- The churning actions of the stomach muscles turns the food into a fluid.
- This increases the surface area for enzymes to digest the food.
7
Q
State the role of the small intestine in digestion.
A
- The small intestine ensures small food molecules produced by digestion are absorbed into the bloodstream either by active transport or diffusion.
8
Q
State the role of the liver in digestion.
A
The liver produces bile.
9
Q
State the role of the pancreas in digestion.
A
- The pancreas releases amylase, protease and lipase.
- These enzymes help to digest carbohydrates, proteins and fats.
10
Q
What are the two roles of bile?
A
- Bile emulsifies lipids. This increases the surface area of the lipid droplets. This increases the rate of lipid breakdown by lipase.
- Bile is alkaline so it neutralises the stomach acid which increases the rate of lipid digestion by lipase.
11
Q
What happens in the small intestine during digestion?
A
Water is absorbed into the bloodstream.
12
Q
What is the role of enzymes?
What are enzymes?
A
To speed up chemical reactions.
Large protein molecules.
13
Q
Explain what happens with the lock and key theory.
What happens if the substrate does not fit into the active site?
A
- The substrate and the enzyme fit together, they are specific to eat other.
The enzyme then breaks down the substrate into the products. - Then the enzyme cannot break the substrate down into products.
14
Q
What are proteins made of?
What happens when we digest proteins?
A
- Amino acids.
- When we digest proteins, the protease breaks down the proteins into amino acids which are absorbed into the bloodstream.
The amino acids are then absorbed by body cells, which join together to make human proteins.
15
Q
Where is amylase produced?
When we digest carbohydrates what is the product?
A
- Salivary glands and pancreas.
- Simple sugars.
16
Q
What does a lipid molecule consist of?
When the lipid molecule is digested, what does it produce?
Where is lipase produced?
A
- A lipid is a molecule consisting of one molecule of glycerol joined to three molecules of fatty acids.
- Glycerol and fatty acids.
- Pancreas and small intestine.
17
Q
Draw a graph showing the relationship between the activity of an enzyme and temperature.
A
18
Q
Why does the rate of activity of an enzyme increase as temperature increases?
A
- Because as the temperature increases, the active site and substrate are moving faster, so there are more frequent collisions.
19
Q
What is the optimum temperature of an enzyme?
What is the definition of optimum temperature?
A
- 37 degrees Celsius (body temperature)
- The temperature at which an enzyme catalysts a reaction at the fastest rate.
20
Q
Fully explain what happens when we increase an enzymes temperature past it’s optimum.
A
- The active site denatures.
- The substrate can no longer fit into the active site.
- The enzyme can no longer catalyse the reaction.
21
Q
Draw a graph showing the relationship between the activity of an enzyme and pH.
A
22
Q
Why does the graph look like this?
Do all enzymes have the same optimum pH?
A
- The active site denatures if the pH is too acidic or too alkaline.
- The enzyme has an optimum pH where it’s activity is at a maximum rate.
- No, all enzymes have different optimum pHs.
23
Q
How is the length of the small intestine ideal for digestion?
A
- The small intestine is very long.
- This provides a big surface area for the absorption of the products of digestion.
24
Q
Name 3 features of villi, and explain how they help the small intestine with the absorption of molecules.
A
- Villi massively increase the surface area of the small intestine, with microvilli on the surface of the small intestine increasing it even further.
- Villi have a good blood supply, so the bloodstream rapidly removes the products of digestion. This increases the concentration gradient.
- The villi have a thin membrane, which ensures a short diffusion path.
All of these features mean that there is a rapid rate of diffusion.
25
Describe how the fish’s single circulatory system works.
- De - oxygenated blood is pumped from the heart to the gills, where it becomes oxygenated.
- The oxygenated blood then passes straight from the gills to the organs.
- The oxygen then diffuses out of the blood, and into the body cells.
- The blood then returns to the heart.
26
What is the problem with the fishes single circulatory system?
- The blood loses lots of pressure when it passes through the gills before reaching the organs.
- This means that the blood travels to the organs quite slowly, so it can’t deliver much oxygen.
27
Describe the humans double circulatory system.
- De - oxygenated blood is pumped from the heart to the lungs where it collects oxygen.
- This oxygenated blood then returns to the heart.
- The heart then pumps the oxygenated blood to the organs where it transfers it’s oxygen to body cells.
- The blood then returns back to the heart.
28
What is the benefit of the double circulatory system?
Because the blood passes through the heart twice, the heart can then deliver the oxygenated blood rapidly to the body cells and they can get the oxygen they need.
29
What kind of tissue is the heart made of?
What is the role of the heart?
1. The heart is made of muscle tissue.
2. The main role of the heart is to pump blood around the body.
30
How many chambers does the heart have?
What are the atria separated from the ventricles by?
1. The heart has 4 chambers.
2. The attire are separated from the ventricles by valves.
31
Describe the passage of the blood around the heart and the lungs.
- The vena cava brings in de-oxygenated blood from the body.
- The blood passes from the heart to the lungs via the pulmonary artery.
- In the lungs, the blood collects oxygen.
- The blood passes back from the lungs to the heart via the pulmonary vein.
- Oxygenated blood is pumped from the heart to the body in the aorta.
32
Describe the pattern of blood flow through the heart.
- Blood enters the heart from the atria.
- The atria contract and the blood is forced into the ventricles.
- The ventricles now contract, and force blood out of the heart.
33
What is the role of the valves?
To prevent the blood from flowing backwards into the atria when the ventricles contract.
34
Which side of the heart has a thicker muscular wall? Why?
- The left side of the heart has a thicker musclular wall than the right side.
- This is because the left ventricle has to pump blood all around the body, so it has to provide a greater force. The right ventricle only pumps blood to the lungs.
35
What is the role of the coronary arteries?
To provide oxygen to the muscle cells of the heart.
36
How is the oxygen the coronary arteries provide used?
The oxygen is used in respiration to provide energy for contraction.
37
What is our resting heart rate controlled by?
Where is it found?
The pacemaker.
- The pacemaker is found in the right atrium.
38
What happens if the pace maker stops working?
Doctors can implant an artificial pacemaker.
- An artificial pacemaker is a small electrical device that corrects irregularities in the heartrate.
39
What is the role of arteries?
Name and explain 2 adaptations the artes have.
1. Arteries carry very high pressure blood from the heart to organs around the body.
2. Arteries have very thick muscular walls which allows them to withstand the high pressure of the blood.
- The arteries contain elastic fibres which stretch when the surge of blood passes through, and recoil between surges. This keeps the blood moving.
40
What happens in capillaries?
- Glucose and oxygen diffuse from the - blood to cells.
- Carbon dioxide diffuses from the cells to the blood.
41
Name 2 adaptations of capillaries.
- Capillaries have very thin walls which provide a very short diffusion pathway. This means that oxygen and glucose can diffuse rapidly from the blood to the cells.
- capillaries have a good blood supply.
42
What is the role of the veins?
Name 3 adaptations of veins.
1. To transport deoxygenated blood from the body back to the heart.
2. Veins have large lumen so lots of blood can travel through at a fast rate.
- Veins have thin walls as the blood is travelling at low pressure.
- Veins have valves to prevent back flow.
43
Explain the role of valves in detail.
- The job of valves is to prevent backflow.
- When blood is flowing int he correct direction, the valves open to allow blood to flow through.
- When the blood starts to flow backwards, the valves shut.
44
Name the 4 components of the blood.
Plasma, WBC, RBCs, Platelets.
45
What is the role of plasma?
- Blood plasma transports soluble digestion products from the small intestine to other organs.
- Plasma transports carbon dioxide from the organs to the lungs to be breathed out.
- Plasma transports urea from the liver to the kidneys to be excreted in our urine.
46
What is the role of RBCs?
RBCs transport oxygen from the lungs to the body cells.
47
Name + explain 3 adaptations of RBCs
1. Red Blood Cells contain haemoglobin which carries oxygen.
2. Red blood cells have no nucleus which means they have more space for haemoglobin.
3. RBCs have a concave shape. This gives them a greater surface area so that oxygen can diffuse in and out rapidly.
48
What is the role of white blood cells?
49
Why is it essential that WBCs contain a nucleus?
Because the nucleus contains DNA which encodes the instructions that the WBC needs to do it’s job.
50
What are platelets?
What is the role of platelets?
1. Platelets are tiny fragments of cells.
2. Their job is to help the blood clot.
51
Name 3 uses of donated blood.
1. Donated blood can be used to replace blood lost during injury.
2. Some people are given platelets extracted from the blood to help with blood clotting.
3. Proteins extracted from the blood can also be useful eg antibodies.
52
Name 2 problems with blood donations.
1. In a blood transfusion, the donated blood has to be the same blood type as the patients. (otherwise the body’s immune system will reject the blood, and the patient could die.)
2. Lots of diseases can be transmitted via blood. There is also risk of infections.
53
What are cardiovascular diseases?
Are they communicable or non communicable?
- CV diseases are diseases of the heart and blood vessels
They are non communicable
54
Explain what coronary heart disease is and what effect it causes.
- In CHD, layers of fatty materials build up inside the coronary arteries.
- This narrows the coronary arteries.
- This then reduces the blood flow through the coronary arteries.
- This results in a lack of oxygen for the heart muscle.
- In extreme cases, this can cause a heart attack.
55
Name the two treatments for CHD.
Statins and Stents.
56
What are statins?
How do they help treat CHD?
1. Statins are drugs which reduce the level of cholesterol in the blood.
2. This reduces the rate that fatty acids build up in the arteries.
57
Name an advantage and a disadvantage of statins.
1. Advantage: Statins have proven to be an effective treatment.
Disadvantage: Statins can cause some unwanted side effects, for example liver problems.
58
What is a stent?
How does it help treat CHD?
What type of people generally have stents inserted?
1. A stent is a tube that is inserted into the coronary artery to keep it open.
2. Because the coronary artery is held open, blood flows through normally and sufficient oxygen is delivered to the heart.
3. In some people, CHD can cause almost a total blockage of the artery. These people are usually treated with stents.
59
Name an advantage and a disadvantage to stents.
Advantage: It helps the blood to flow normally through the coronary artery.
Disadvantage: It doesn’t treat the underlying cause of the disease - other parts of the coronary artery can still narrow.
60
Name two problems people can have with their heart valves.
- Sometimes, the heart valves don’t open fully so the heart has to pump extra hard to get the blood through. This can cause the heart to enlarge.
- Other times a persons valves may become leaky, this can cause the patient to feel weak and tired.
61
How do we replace faulty valves?
- We replace faulty valves either with a mechanical valve made from metal, or from a valve from animals.
62
Name an advantage and a disadvantage of mechanical valves.
Advantage: Mechanical valves can last a lifetime.
Disadvantage: They can cause blood clotting, so patients have to take anti clotting drugs.
63
Name an advantage and disadvantage with animal valves.
Advantage: They do not have blood clotting side effects, so patients don’t need to take anti clotting drugs.
Disadvantages: They do not last as long as mechanical valves and often need to be replaced.
64
What is heart failure?
How is heart failure often treated?
1. Heart failure is when the heart cannot pump enough blood around the body.
2. These patients are often given a donated heart or donated heart + lungs.
65
What is the problem with this treatment?
1. There are not enough heart’s available to treat every patient.
2. The patient must take drugs to stop the heart being rejected from their immune system.
66
1. What might patients be given as a temporary measure while waiting for a heart transplant?
2. Why is this treatment method not a long term method?
1. They may be given an artificial heart.
2. Artificial hearts increase the risk of blood clotting.
67
Describe the passage of air into the lungs.
1. Air passes into the lungs through the trachea.
2. The trachea splits into two smaller tubes called bronchi. One bronchi leads to each lung.
3. Further down into the lungs, the bronchi divide into lots of bronchioles.
4. The bronchioles end on alveoli, which are tiny air sacs where gas exchange takes place.
68
What is the trachea?
Describe one key feature of the trachea.
1. The trachea is a tube that air passes through to get to the lungs.
2. The trachea has rings of cartilage, which prevent it from collapsing during inhalation.
69
What is gas exchange?
Where gases diffuse in and out of the bloodstream.
70
Name 3 adaptations of alveoli.
1. There are millions of alveoli in the lungs. This means that the lungs have a huge surface area.
2. The alveoli have a short diffusion path because their walls are very thin.
3. The alveoli have a very good blood supply. This means that once oxygen enters the blood, it is rapidly removed. This keeps the concentration gradient as steep as possible.
71
What do these adaptations ensure?
That oxygen diffuses rapidly into the bloodstream, and carbon dioxide diffuses rapidly out.
72
How does breathing increase the rate of diffusion?
- Breathing brings fresh oxygen into the alveoli and takes away carbon dioxide.
- This makes the concentration gradient high for the gases, which increases the rate of diffusion.
73
How is mitosis tightly controlled?
What leads to uncontrolled mitosis?
What does uncontrolled mitosis create?
1. Genes in the nucleus tell the cells when to divide and when to stop dividing.
2. Sometimes changes take place in the genes which leads to uncontrolled mitosis.
3. This produces a tumour.
74
What is a benign tumour?
What is a benign tumour usually contained by?
Benign tumour: A growth of abnormal cells found in one area.
- Benign tumours are usually contained within a membrane.
75
What is the key difference between benign and malignant tumours?
Benign tumours do not invade other parts of the body - they stay in one place. Malignant cells invade neighbouring tissues and move into the bloodstream.
76
What are malignant tumours classes as?
What are secondary tumours?
1. Cancer.
2. Secondary tumours are the new tumours malignant cells form as they spread into different parts of the body.
77
Name 3 lifestyle choices that can lead to an increase risk of cancer.
Smoking - Lung cancer.
UV light - Skin cancer.
Alcohol - mouth and throat cancer.
78
1. What is radon?
2. How does it increase our risk of developing cancer?
1. Radon is a radioactive gas. It can increase your risk of developing lung cancer.
2. Radon releases ionising radiation. This damages the DNA in our cells.
- This can cause our cells to under go uncontrolled cell division leading to cancer.
79
What are communicable diseases?
How are they spread?
1. They are diseases that can be spread from person to person.
2. Communicable diseases are spread by pathogens such as bacteria or viruses.
80
1. What are non communicable diseases?
2. What is the definition of health?
3. Name 3 things that can have a negative impact on health.
1. Non communicable diseases are diseases that can’t be spread from person to person.
2. Health is defined as a state of physical and mental well being.
3. Poor diet, stress, disease.
81
Explain how HIV can cause TB to become fatal.
- TB is a communicable lung disease.
- Most people’s immune system can fight off TB.
- However some people have a defective immune system, eg people with HIV.
- People with defective immune systems are more likely to suffer from infectious diseases.
82
How can illnesses cause allergies?
Sometimes, the body is infected with a pathogen, which is then fought off by the immune system, however can leave people with allergies.
83
Explain how a physical illness can lead to a mental illness.
- Arthritis is a painful joint condition.
- It can make it difficult to move and lead a normal life.
- This can lead to isolation and depression.
84
Give an example of how one illness can lead to another.
HPV is a common, usually harmless disease.
- However, rarely, it can lead to cervical cancer.
- The HPV virus infects the cells of the cervix and causes cervical cancer.
85
What is epidemiology?
When you study the patterns of a disease to determine risk factors.
86
How did scientists figure out there was a correlation between lung cancer and cigarette smokers?
- Scientists looked at how many cigarettes people smoked each day.
- They then looked at how many people developed lung cancer.
- In order to determine whether there was a correlation, the scientists would have plotted a scatter graph.
- It would have shown a positive correlation.
87
What is a positive correlation?
Hay is a negative correlation?
Does a correlation prove cause? Why/ why not?
1. A positive correlation shows that when one variable increases, so does the other variable.
2. A negative correlation shows that when one variable increases, the other variable decreases.
3. No. It simply shows there is a link.
88
What are carcinogens?
Carcinogens are chemicals which damage DNA and increase the risk of cancer.
89
What is the problem with sampling.
- Scientists sample a group of people and try to draw conclusions from the whole population.
- If we select a bias sample, for example a group of people from only one town, it would not give us an accurate representation of the whole population.
90
How do we avoid bias sampling?
- We need to take as large a sample as possible.
- The sample needs to be as random as possible
91
Are non communicable diseases caused by pathogens?
Provide 3 examples of non communicable diseases.
No.
- Cardiovascular Diseases, Type 2 diabetes, Most types of cancer.
92
Name 3 risk factors for cardiovascular diseases
1. Diet - salt + high fat foods.
2. Smoking.
3. (Lack of ) exercise
93
How does your diet increase your risk for cardiovascular disease?
1. A diet that’s high in fat and low in vegetables can increase your blood cholesterol.
- this increases the rate that fatty acids build up in your arteries.
2. A diet high in salt can increased your blood pressure.
94
What are the effects of smoking when pregnant?
1. Smoking when pregnant increases the risk of miscarriage and premature birth.
2. It can also lead to the Abby being born with a low body mass.
95
What effects does drinking alcohol have on pregnancy?
Drinking alcohol when pregnant can increase the risk of fetal alcohol syndrome. This can lead to learning disabilities and physical problems.
96
Name 3 affects of drinking alcohol.
1. Liver cirrhosis
2. Liver cancer
3. Addiction + memory loss.
97
Name 2 things type 2 diabetes can lead to.
1. Blindness
2. Amputation of a limb.
98
Why do obese people have a higher risk of developing diabetes?
Lots of excess fat can cause insulin resistance and cell dysfunction.
99
Explain how risk factors can interact.
Drinking excess alcohol can lead to obesity, which increases the risk of developing type 2 diabetes
100
What is the job of the upper and lower epidermis?
Name an adaptation of the upper epidermis.
1. They protect the surface of the leaf.
2. The upper epidermis is transparent, which allows light to pass through to the photosynthetic cells below.
101
What is the job of the waxy cuticle?
What is an adaptation of the waxy cuticle?
1. The waxy cuticle reduces water evaporation from the surface of the leaf. This helps to prevent the leaf from drying out.
2.
102
What are the roles of the stomata?
1. Stomata allow oxygen to leave the leaf and carbon dioxide to enter.
- they also help to control the amount of water vapour that can pass out of the leaf.
103
What is the role of the palisade mesophyll cells?
Name an adaptation that they have.
1. The palisade mesophyll is where photosynthesis takes place.
2. The palisade mesophyll cells are full of chloroplasts which absorb the light needed for photosynthesis
104
What is the role of the spongy mesophyll?
The air spaces in the spongy mesophyll allow carbon dioxide to diffuse from the stomata through the spongy mesophyll to the palisade cells.
(Oxygen does the same but the other way around to leave the cell)
105
What happens to the dissolved sugars that the phloem carries?
The dissolved sugars can be used immediately- glucose is in respiration or can be stored as starch
106
What is translocation?
Translocation is the movement of sugars and other molecules through the phloem tissue.
107
What is transpiration.
Transpiration is when water evaporates from the surface of the leaves.
108
Describe the process of the transpiration stream.
1. Transpiration starts with the evaporation of water from cells inside the leaf.
2. The water vapour then diffuses through the air spaces in their spongy mesophyll and out of the leaf through the stomata.
3. Water then passes from the xylem into the leaf to replace the water that’s been lost.
4. Finally, water is drawn into the root hair cells and the xylem vessels to the leaf.
109
Name 3 reasons why transpiration is an important process.
1. Transpiration brings water to the leaf which is required for photosynthesis.
2. The transpiration stream transports dissolved mineral ions like magnesium which play important roles in the plants.
3. The evaporation of water from the leaf coolers the leaf down.
110
Name the 4 factors that affect the rate of transpiration.
1. Light intensity - high light intensity increases the rate of transpiration as it increases the rate of photosynthesis. The stomata open to allow carbon dioxide to enter and water vapour can then pass out of the leaf.
2. High temperatures increase the rate of transpiration as evaporation is faster when temperatures are higher.
3. Transpiration is faster in dry condition because evaporation takes place more quickly under dry conditions.
4. The rate of transpiration is faster under windy conditions because wind removes any water vapour, allowing more water to evaporate.
111
What are the stomata surrounded by?
Guard cells.
112
What happens to the guard cells when the light intensity is high?
How does this impact the stomata?
The guard cells swell and change their shape. This causes the stomata to open.
113
What happens when the stomata are open?
Carbon dioxide diffuses into the leaf and is used in photosynthesis
114
Why is the stomata shut in hot conditions?
The plant closes the stomata to reduce the water loss from transpiration. However, this means that the plant can’t photosynthesise.
