Organisation Flashcards
1
Q
What is a cell?
A
A cell is the fundamental unit that make up all living organisms.
2
Q
What is the purpose of mesophyll?
A
Mesophyll is capable of photosynthesis
3
Q
What can muscular tissues do?
A
Can contract to bring about force and motion and move contents of the stomach around during digestion.
4
Q
What is epithelial tissue?
A
Epithelial tissue lines the stomach and outer surface of organs and blood vessels.
5
Q
What are some examples of epidermal tissue?
A
Examples of epidermal tissues:
- Human skin
- Waxy covering of some plants
6
Q
What is the glandular tissue?
A
The glandular tissue produces digestive juices that break down the stomach’s contents.
7
Q
What are organs?
A
Organs are genius of distinctive tissues that work together to perform a specific function.
8
Q
What is a tissue?
A
A group of cells together to organised to perform one or more specific functions.
9
Q
What is am organ system?
A
Organs systems are groups of organs that work together to perform a particular role.
10
Q
What organs is the digestion system made up of?
A
- Large intestine
- Glands
- Small intestine
- Liver
- Stomach
11
Q
Why is the large intestine important?
A
It absorbs water molecules from the remaining food, this allows it to produce faeces.
12
Q
What do glands produce?
A
They produce digestive enzymes
13
Q
Why is the small intestine important?
A
It digests food and absorbs solube food molecules
14
Q
What does the liver produce?
A
The liver produces bile
15
Q
What does the stomach digest?
A
The stomach digests food
16
Q
What is an organism?
A
An organism is the highest of organisation in a multicellular organism, consisting of several organ systems.
17
Q
What is an enzyme?
A
Enzymes increase the speed of reactions, often called biological catalysts.
18
Q
How do you catalyse a reaction?
A
To catalyse a reaction, the reacting chemical must bind to the enzyme’s active site.
19
Q
Why won’t the active site always function?
A
The active site will only fit specific substrates.
20
Q
What is lock and key?
A
The active site is like a lock, and the substrate is a key. There is usually one enzyme for every substrate.
21
Q
What does denatured mean?
A
An enzyme is denatured if its structure is altered and it can no longer catalyse a reaction
22
Q
What type of molecule is an enzyme?
A
Protein
23
Q
How do you calculate the rate of reaction from a graph of mass of product against reaction time?
A
The rate of reaction is equal to the gradient of the graph, which shows the mass of the product plotted against reaction time.
24
Q
What are the factors that affect the rate of enzyme reaction?
A
- pH (measure of acidity)
- Temperature
25
How do you calculate the rate of reaction?
The rate of reaction is equal to the gradient of the graph.
26
In a reaction involving enzymes, the change in mass is 10g and the change in time is 60 seconds. What is the rate of reaction?
10 ÷ 60 = 0.167 g/s
27
How are digestive enzymes made?
Digestive enzymes are made by specialised cells in the glands and the gut lining. They are then secreted out of the body cells and into the cavity of the digestive system.
28
What are the main three digestive enzymes?
1) Amylase
2) Lipase
3) Protease
29
Describe the process of the breakdown of large food molecules.
The digestive enzymes catalyse the breaking down of large and insoluble molecules of food into smaller, soluble molecules that can be absorbed into the bloodstream. Digested molecules can be used to construct new carbohydrates, proteins and lipids in the body. Some glucose produced by digestion is used for respiration.
30
What is digestion?
Digestion is the breakdown of large food molecules.
31
What is bile?
Bile is an alkaline substance produced in the liver and stored in the gallbladder.
32
Why is bile important?
Bile is important as there is optimal enzyme conditions and emulsification.
33
Why does bile have optimal enzyme conditions?
- Enzymes in the small intestine operate best in alkaline conditions.
- Bile neutralises acid from the stomach to stop these enzymes from becoming denatured.
34
What is emulsification in bile?
- Bile breaks up fats into tiny droplets through a process called emulsification.
- The tiny droplets have a higher surface area than the original fat drop.
- This increases the rate of the lipase-catalysed reactions that break fats down.
35
What is amylase?
Amylase is a type of carbohydrase that can break down starch in our bodies.
36
What do carbohydrase enzymes do?
Carbohydrase enzymes break down Carbohydrates down into sugars.
37
Where is amylase produced?
- Pancreas
- Salivary glands
38
Where are the action sites of amylase?
- The mouth
- The small intestine
39
What is the purpose of amylase?
Amylase breaks down starch into its constituent simple sugars
Starch -> Maltose (+ other sugars)
40
What are proteases?
Proteases are digestive enzymes that can break down proteins into amino acids.
41
Where are proteases produced?
- Pancreas
- Stomach
42
What is the purpose of protease?
Protease breaks down proteins into amino acids
Protein -> amino acids
43
Where are the action sites of protease?
- Small intestine
- Stomach
44
What is lipase?
Lipase is a type of digestive enzyme that breaks down lipids into glycerol and fatty acids.
45
Where is lipase produced?
- Pancreas
- Small intestine
46
What is the purpose of lipase?
Lipase breaks down lipids into a molecule called glycerol and fatty acids.
47
What is the first step for testing for carbohydrates, proteins and lipids?
Grind up the food and add distilled water to dissolve some of the food.
48
How do you test for lipids?
To test for lipids:
- Add Sudan III (fat-soluble dye)
- If present, a red stained oil layer will float on the water surface.
- If not present, there will not a be red stained oil layer.
OR
- Presence of lipids can be tested by using ethanol
- The solution is added to water and shaken, if the solution turns cloudy, lipids are present.
49
How to test for proteins?
- Add Biuret solution to test for proteins.
- It present, it will turn mauve or purple.
50
How do you test for sugars?
- Add Benedict's reagent and heat for about two minutes to test for sugar.
- If sugar is present, it will turn green, yellow or red (depends on concentrated).
51
How do you test for starch?
- Add iodine solution to test for starch
- If present, it will turn black/blue
52
What are two advantages and two disadvantages of using enzymes in washing powder?
- Enzymes are very effective at removing stains.
- Enzymes can ve used at low temperatures, saving energy and costs.
- Enzymes may enter natural water sources, causing pollution.
- Enzymes may digest the material of clothing.
53
What are the three different types of blood vessels?
1) Arteries
2) Veins
3) Capillaries
54
What is the function of blood vessels?
Blood vessels help blood move around the body.
55
What is the function of arteries?
Arteries transport blood from the heart to the organs. They all cary oxygenated blood (apart from the pulmonary artery).
56
How is the structure of the arteries adapted to perform their function?
Elastic fibres - The walls have elastic fibres, allowing them to stretch and spring back.
Thick muscle walls - This makes them string and able to cope with the high pressure at which blood is pumped out by the heart.
57
What is the function of capillaries?
Capillaries have thin walls and pass very close to the body cells.
58
What can be efficiently exchanged between the capillaries and body cells?
Food and oxygen - They move out of the blood and into the cells.
Waste products - In capillaries, waste products such as carbon dioxide move out the cells and into the blood.
59
How are veins formed?
Veins are formed when capillaries join up after passing through the body.
60
What is the function of veins?
Veins transport deoxygenated blood (apart from the pulmonary veins) from the organs back to the heart.
61
How are veins different to arteries?
Thinner walls - Due to blood being at a lower pressure.
Wider cross-section - Low pressure hinders blood flow. Blood flows to counteract this.
Valves - Veins have valves to prevent the backflow of blood.
62
What are the four Chambers in the heart called?
Left/Right atrium and Left/Right ventricle
63
Where are the atriums and ventricles placed?
Atrium - top of the heart
Ventricle - bottom of the heart
64
How do combined resistors in parallel work?
The combined resistance if two resistors in parallel is less than the resistance of either of the two resistors by themselves.
65
What are the advantages of connecting bulbs in a parallel in a house?
They can be independently switched on and off and if one bulb breaks, the others are not affected.
66
What does a group of cells do in the right atrium?
They act as a pacemaker, controlling the pumping of the heart.
67
What happens when a heart beats?
- Blood enters via the atria
- The atria contract (forcing boood down into the ventricles)
- Ventricles contract (forcing the blood to exit the heart)
68
Why might someone be fitted with an artificial pacemaker?
- Normally, a group of cells in the right atrium act as a pacemaker to control the heart's beating.
- If these cells don't work properly, irregular heart rates can be corrected using electrical devices, known as artificial pacemakers.
69
What are the most important blood vessels called?
- Vena Cava
- Aorta
- Pulmonary Vein
- Pulmonary Artery
- Coronary Arteries
70
What is the function of the vena cava?
The heart receives deoxygenated blood from the body through a vein called the vena cava.
71
What is the function of the pulmonary vein?
The heart receives oxygenated blood from the lungs through the pulmonary vein.
72
What is the function of the aorta?
The heart pumps out oxygenated blood to the body through the aorta.
73
What is the function of the pulmonary artery?
The heart pumps out deoxygenated blood to the lungs through the pulmonary artery.
74
What is the function of coronary arteries?
The coronary arteries supply the heart muscle with oxygenated blood.
75
What is the double circulatory system?
The hunan circulatory system has 3 key components: heart, blood and blood vessels. It is called a double circulatory system because blood passes through the heart twice on each circuit.
76
How does blood travel around the body?
- Blood enters the heart = deoxygenated blood enters into the right of the heart.
- Blood pumped to the lungs = deoxygenated blood is pumped out of the heart towards the lungs by the right ventricle.
- Lungs oxygenate the blood = deoxygenated blood exchanged carbon dioxide for oxygen, becoming oxygenated.
- Blood returns to the heart = oxygenated blood returns to the left atrium of the heart.
- Blood is pumped to the body = oxygenated blood is pumped out of the heart and to the body by the left ventricle.
- Blood returns to the heart again = oxygenated blood gives its oxygen to body cells in exchange for carbon dioxide. The blood becomes deoxygenated.
77
What process does the body use oxygen for?
Respiration
78
How is gas exchanged in the lungs?
Deoxygenated blood arrives at the lungs from the heart via the pulmonary artery. The lungs oxygenate the blood before it returns to the heart through the pulmonary vein.
79
What is the pathway for oxygen to enter the blood?
- Air is breathed into the lungs through the trachea.
- The trachea divides into two tubes called the bronchi.
- The bronchi divide to form bronchioles.
- The bronchioles divide until they end up in tiny air sacs called alveoli.
80
What are alveoli surrounded by?
They are surrounded by a network of capillaries, allowing for oxygen and carbon dioxide to be exchanged between the blood in capillaries and the air in the lungs. (There are millions of alveoli).
81
What is the equation for breaths per minute?
Breaths per minute = number of breaths ÷ number of minutes
82
What are alveoli?
Alveoli are tiny air sacs that are found in the lungs. Oxygen and carbon dioxide move between the air and blood by diffusion in the alveoli.
83
What are alveoli adapted for?
Alveoli are adapted so the exchange of substances across their surface is very efficient.
- Large surface area
- Surrounded by capillaries
84
What is blood?
Blood is a tissue. Made up of a fluid called plasma, white blood cells, red blood cells and platelets.
85
What are platelets?
Platelets are small cell fragments that do not have a nucleus and are responsive for triggering blood clotting at the sight of wounds.
86
What is the role of a red blood cell?
Red blood cells transfer oxygen from the lungs to all body cells.
87
What features of a red blood cell are adapted to do their function?
Biconcave shape - Bigger surface area = rapid diffusion of oxygen.
Haemoglobin - Carries oxygen which is then released to the body cells, used for respiration.
Small size - So they can pass through capillaries.
No nucleus - More room for Haemoglobin = more room for oxygen.
88
What is the role of a white blood cell?
White blood cells defend against infections.
89
What are the two adaptations of white blood cells?
1) Can change shape - Allows them to squeeze through walls of blood vessels into body tissues to engulf harmful microorganisms.
2) They have a nucleus.
90
Which chamber of the heart has the thickest wall?
Left ventricle
91
What are the two different types of diseases?
1) Communicable diseases - Can be spread between organisms.
2) Non-communicable diseases - Cannot be spread between organisms.
92
What can cause different diseases to interact with one another (leading to declining health)?
Mental health - Physical problems can negatively impact upon an individuals mental health.
Immune system - A disease that suppresses the immune system that makes individuals more susceptible to catching other infectious diseases.
Cancer - Viruses occupying cells can stimulate cancers.
Allergies - Can be triggered by an immune reaction to a pathogen.
93
How does sampling work for big populations?
If a population is so large, not everybody can be tested. Instead, we take a sample and assume that the pattern is true for the whole population.
94
What factors affect health?
- Disease
- Diet
- Stress
- Life situations
95
What are risk factors?
Risk factors are factors that increase the probability of developing a disease. Often, non-communicable diseases arise due to the interaction of numerous risk factors.
96
What are the two different types of risk factors?
-Substances (the individual's body or the environment).
- Lifestyle (like an unbalanced diet or not enough exercise).
97
What are the risk factors for cardiovascular disease?
Poor diet
Smoking
Lack of exercise
98
What is a risk factor for type 2 diabetes?
Obesity
99
What is a risk factor for the low birth weight of babies?
Smoking during pregnancy
100
What is a risk factor for cancer?
Exposure to ionising radiation
101
What is a risk factor of lung diseases?
Smoking
102
What is a risk factor for brain damage in babies?
Excessive alcohol consumption during pregnancy
103
What is a risk factor for liver and brain damage?
Excessive alcohol intake
104
What is coronary heart disease?
Coronary heart disease is a non-communicable disease, that causes the coronary arteries to narrow due to a build-up of fatty deposits. This reduces blood flow and leads to a lack of oxygen being supplied to the heart muscle.
105
How can heart valves become faulty?
Leaky valves - Allows the backflow of blood. This forces your heart to do more work to circulate the same amount of blood. This creates a strain on the heart.
Valves that don't fully open - This can obstruct blood flow. So, a greater force is required to force the blood through the body, also adds a strain on the heart.
106
How can faulty valves be fixed?
Animal or artificial valves can be inserted to replace faulty valves. Although this is less drastic than a heart transplant, it still involves major surgery and problems with blood clots can happen.
107
What are the benefits of artificial hearts?
Artificial hearts are unlikely to be rejected by the patient's immune system, qo immunosuppressant drugs are unnecessary.
Artificial hearts can be used to provide the heart with some rest to allow it to recover.
108
What are the drawbacks of artificial hearts?
Artificial hearts can result in long and expensive stays in hospital.
They can cause blood clotting, which potentially can lead to strokes.
109
Why might someone be given artificial hearts while they wait for a heart donor?
Immediate transplantation isn't always available.
110
What procedure may be necessary in the case of heart failure?
Transplant of a donor heart
111
What are the two most common treatments for coronary heart disease?
1) Stents
2) Statins
112
How are stents treatment for coronary heart disease?
Stents are inserted in order to keep coronary arteries open.
Over time, because of irritation caused by the stent, the artery can begin to narrow again as scar tissue builds up.
Drugs must be taken to prevent blood clotting on the stent.
113
What are statins and how do they work against coronary heart disease?
Statins are drugs that can be taken to decrease blood cholesterol levels.
Statins help to slow slow the build up of fatty materials.
As with most medications, statins can have side effects.
114
What are the advantages and disadvantages of drugs for treatment of heart diseases?
+ Often cheap to buy, and do not require surgery.
~ May have side effects, and the patient has to remember to take them.
115
What are advantages and disadvantages of using mechanical devices as treatment of heart diseases?
+ Used in cases where an organ donor is not available.
~ Require a power supply, and may eventually wear out and need replacing.
116
What are the advantages and disadvantages of transplants as treatment for heart diseases?
+ Successfully transplanted organs won't wear down, and will function like the replaced organ.
~ Require a suitable donor and immunosuppressants, which can increase the risk of the patient getting another disease.
117
What is cancer?
Cancer is a group of diseases where changes in cells lead to uncontrolled growth and division of cells.
118
What are the two types of cancer tumours?
1) Malignant tumours
2) Benign tumours
119
What are malignant tumours?
Malignant tumours can invade neighbouring tissues and spread throughout the body in the blood, leading to the creation of more secondary tumours.
120
What are benign tumours?
Benign tumours stay in a specific part of the body, often within a membrane.
121
What are the two different types of risk factors for various cancers?
1) Lifestyle
2) Genetic
122
What are the three factors that have been identifies to increase the risk of some cancers by lifestyle choice?
1) Smoking
2) Obesity
3) UV exposure (e.g. through lots of sunbathing)
123
How can an increased risk of cancer be genetic?
Could be inherited from your parents (e.g. types of breast cancer).
124
What are the four major plant organs?
1) Roots
2) Stems
3) Leaves
4) Reproductive structures
125
Where can meristem tissue be found growing?
Meristem tissue can be found at the growing tips of roots and shoots. (The undifferentiated cells of meristem tissue repeatedly divide and grow).
126
What are the four different types of tissues that make leaves?
1) Stomata
2) Spongy mesophyll
3) Epidermal tissue
4) Palisade mesophyll
127
What is the function of the stomata?
Stomata is found in the lower epidermis, their gaps facilitate the diffusion of gases in and out of the leaf, if they are open.
When necessary, specialised guard cells are capable of closing these gaps (e.g. in hot weather to reduce water loss).
128
What is the function of the palisade mesophyll?
Palisade mesophyll is a row of cells located below the upper epidermis. The cells are exposed to a lot of sunlight. The cells have lots of chloroplasts to maximise the energy transfer in photosynthesis.
129
What is the function of epidermal tissue?
Epidermal tissue covers the outer surface of leaves (as well as the rest of the plant).
130
What is the function of spongy mesophyll?
Spongy mesophyll contains many air spaces, which help with gas exchange throughout the leaf.
131
Why does palisade mesophyll have a lot of chloroplasts?
To maximise energy absorbed for photosynthesis.
132
What is transpiration?
Transpiration is when water is lost from the leaves. Transpiration transports water and the minerals dissolved in it through the plant.
133
How does water move through a plant?
Water moves through a plant in only one way: from the roots to the leaves.
134
How are water/minerals taken up in root hair cells?
Root hair cells absorb water from the soil via osmosis.
Mineral ions are taken up by active transport.
135
What happens to the water/minerals after being absorbed by root hair cells?
After being absorbed by root hair cells, the water and minerals are carried in xylem vessels up the stem and into the leaves.
136
What happens to water once it reaches the leaves?
Once the water reaches the leaves, most of it evaporates and the water vapour diffuses out through open stomata.
137
What vessels transport water and minerals up the stem and into the leaves?
The xylem vessel
138
What factors affect the rate of transpiration?
Light intensity - Increased light intensity makes water evaporate quicker = increased rate of transpiration
Air flow - increased air flow = increased rate (air flow carries water away from the plants leaves).
Temperature - Increased temperature = increased rate (makes water evaporate faster).
Humidity - increased humidity = decreased rate (increases water in the air, difficult to evaporate).
139
What apparatus is used to calculate the rate of transpiration?
Potometer
140
When measuring the rate of transpiration with a potometer, why is the calculation only an estimate?
A small amount of water taken up by the shoot is used in the leaves and is not transpired.
141
What is translocation?
Translocation is the process by which food produced in photosynthesis is transported from the leaves to the growing regions of plants and storage organs.
142
What are the features of translocation?
- Phloem tubes
- Bidirectional
143
Why does translocation occur in the phloem tubes?
Phloem tubes are made up of columns of elongated cells that have holes in the end walls. These holes allow cell sap to pass between the cells.
144
How does transpiration and translocation differ?
Unlike water transport (transpiration), translocation is bidirectional.
145
How are xylem cells adapted for allowing water and minerals to be transported?
- Dead cells
- Lignin
- No end walls
146
Why are xylem cells dead?
The xylem tubes are hollow, therefore their resistance to water flow is low.
147
What does lignin do to the xylem vessels?
It strengthens and waterproofs the elongated cells.
148
What does it mean for xylem vessels to have no end walls?
Having no end walls means that successive cells form a long tube for ease of transport.
149
What happens to the guard cell when opening and closing the stomata?
Open - guard cells take up lots of water, causing them to swell.
Closed - guard cells lose water and return to a limp state.
150
What happens when water is abundant in the plant?
When water is abundant, the plant can afford to lose water. It opens the stomata to allow gases for photosynthesis to move freely in and out of the leaf.
151
What happens when water is scarce in the plant?
When water is scarce, the stomata closes in order to prevent further water loss.
152
Why does the stomata close at night?
At night, stomata close because in the absence of sunlight, carbon dioxide is not required for photosynthesis. At this time, their only objective is to prevent water loss.
153
How would a plant be affected if grown in magnesium-deficient soil?
The production of chlorophyll would decrease. This is called chlorosis.
