B2 - Organisation Flashcards
Cell organisation, enzymes, investigating enzymatic reactions, enzymes and digestion, food tests, lungs, heart, blood vessels, blood, cardiovascular disease, health and disease, risk for tours for non communicable diseases, cancer, plant cell organisation, transpiration, translocation, stomata (191 cards)
1
Q
Cell Organisation -
What are cells?
A
basic building blocks that make up all living organisms
2
Q
Cell Organisation -
When does differentiation occur?
A
during development of multicellular organisms
3
Q
Cell Organisation -
What do specialised cells form?
A
tissues
4
Q
Cell Organisation -
What do tissues from?
A
organs
5
Q
Cell Organisation -
What do organs form?
A
organ systems
6
Q
Cell Organisation -
What do multicellular organisms have different systems inside them for?
A
- exchanging + transporting materials
7
Q
Cell Organisation -
What is a tissue?
A
Group of similar cells that work together to carry out a particular function
8
Q
Cell Organisation -
What are examples of tissues in mammals?
A
- muscular tissue (contract to move whatever they’re attached to)
- glandular tissue (makes + secretes chemicals eg enzymes and hormones)
- epithelial tissue (covers some parts of body eg inside of gut)
9
Q
Cell Organisation -
What are organs?
A
A group of different tissues that work together to perform a certain function.
10
Q
Cell Organisation -
What is an example of an organ and the tissues it consists of?
A
Stomach:
- muscular tissue: moves stomach wall to churn food
- glandular tissue: make digestive juices to digest food
- epithelial tissue: cover the outside + inside of stomach
11
Q
Cell Organisation -
What is an organ system?
A
A group of organs working together to perform a particular function
12
Q
Cell Organisation -
What is an example of an organ system and the organs its made of?
A
Digestive system - breaks down + absorbs food
- glands (pancreas, salivary glands) - produce digestive enzymes
- stomach + small intestine - digest food
- Liver - produces bile
- Small intestine - absorbs soluble food molecules
- large intestine - absorbs water from undigested food + leave faeces
13
Q
Cell Organisation -
What do organ systems to make?
A
Organisms
14
Q
Enzymes -
What are enzymes?
A
Biological catalysts
15
Q
Enzymes -
What do enzymes reduce the need for?
A
- high temperatures
- speed up rate of useful chemical reactions in body
16
Q
Enzymes -
What is a catalyst?
A
A substance which increases the speed of a reaction, without being changed or used up in the reaction
17
Q
Enzymes -
What are enzymes all?
A
Proteins made up of chains of amino acids
18
Q
Enzymes -
What does every enzyme have?
A
An active site with unique shape
19
Q
Enzymes -
Why do enzymes have an active site with a unique shape?
A
So fit onto substances involved in a reaction
20
Q
Enzymes -
What happens if the substances doesn’t fit into the active site of the enzyme?
A
The reaction won’t be catalysed
21
Q
Enzymes -
What model is used to represent the action of enzymes?
A
Lock and Key model
22
Q
Enzymes -
What happens when a substances fits into the active site of an enzyme and the name of that model?
A
- Active site changes shape slightly as substrate binds to it to get tighter fit.
- ‘induced fit’ model of enzyme action
23
Q
Enzymes -
What is the substance that an enzyme acts on called?
A
Substrate
24
Q
Enzymes -
What conditions do enzymes need?
A
- optimum temperature
- optimum pH
25
Enzymes -
What happens to the enzyme if the temperature is too high?
- bonds holding enzyme together break + cause shape of active site to change so substrate won't fit means enzyme is denatured
26
Enzymes -
What happens to an enzyme if the pH is too high or too low?
pH interferes with bonds holding enzyme together + causes active site to change shape and denature enzyme
27
Enzymes -
What is often the optimum pH of an enzyme?
pH 7
not always:
- pepsin enzyme used to break down proteins in stomach best at pH 2 means well suited to acidic conditions)
28
Investigating Enzyme Reactions - RP
How can you investigate the effect of pH on enzyme activity + method:
amylase catalyses the break down of starch to maltose - detect starch using iodine solution (if starch present iodine change from browney -orange to blue - black)
Method to investigate how pH affects amylase activity:
1. drop iodine solution in well of spotting tile
2. place bunsen burner on heat proof mat + tripod and gauze over bunsen burner.
3. Put beaker of water on top tripod + heat until 35 degree Celsius Use thermometer)
4. Use syringe to add 1 cm cubed of amylase solution + 1 cm cubed of buffer solution (pH 5) to boiling tube.
5. Use test tube holders, put tube into beaker of water and wait 5 minutes.
6. Use different syringe add 5 cm cubed of starch solution to boiling tube + immediately mix content of boiling tube and start stop watch
7. Use continuous sampling to record how long take for amylase to break down all starch. To do this, use dropping pipette + take fresh sample from boiling tube every 30 secs + put drop into well (when iodine remains browny - orange starch not present)
8. Repeat whole experiment with buffer solution of different pH.
9. Control variables = conc + volume of amylase solution to make fair test
29
Investigating Enzyme Reactions - RP
What is the equation to calculate rate of reaction?
Rate = 1000 / time
30
Investigating Enzyme Reactions - RP
What do you use to calculate rate of reaction if measuring how much something changes over time?
Amount change / time taken
31
Enzymes and Digestion -
What are the enzymes in digestion produced by and where are they released into to mix with food?
Produced by cells and then released into gut
32
Enzymes and Digestion -
What are examples of big molecules?
- starch
- proteins
- fats
33
Enzymes and Digestion -
What does being a big molecule mean?
Can't pass through walls of digestive system so digestive enzymes break them down into smaller molecules that can pass through wall of digestive system and allowing them to be absorbed into bloodstream
34
Enzymes and Digestion -
What do carbohydrase convert carbohydrates into?
Simple sugars
35
Enzymes and Digestion -
What is an example of a carbohydrase?
Amylase
36
Enzymes and Digestion -
Where is amylase made?
- salivary glands
- pancreas
- small intestine
37
Enzymes and Digestion -
What does amylase break down starch into?
Maltose
38
Enzymes and Digestion -
What is starch an example of?
Carbohydrate
39
Enzymes and Digestion -
What do protease convert protein into?
Amino acids
40
Enzymes and Digestion -
Where are proteases made?
- stomach
- pancreas
- small intestine
41
Enzymes and Digestion -
What is protease called in the stomach?
pepsin
42
Enzymes and Digestion -
What does lipase convert lipids into?
Fatty acids and glycerol
43
Enzymes and Digestion -
What are lipids?
Fats and oils
44
Enzymes and Digestion -
Where are lipases made?
- pancreas
- small intestine
45
Enzymes and Digestion -
What are products of digestion used to make in the body?
- carbohyrates
- proteins
- lipids
- some glucose made used in respiration
46
Enzymes and Digestion -
What does bile do?
- neutralises acids
- emulsifies fats
47
Enzymes and Digestion -
Where is bile produced?
Liver
48
Enzymes and Digestion -
Where is bile stored?
Gall bladder
49
Enzymes and Digestion -
Where is bile released into after being stored in the gall bladder?
small intestine
50
Enzymes and Digestion -
Is bile alkaline or acid?
alkaline
51
Enzymes and Digestion -
What does the hydrochloric acid in the stomach mean for enzymes?
pH too acid for enzymes in the small intestine to work properly.
52
Enzymes and Digestion -
What does bile do?
- neutralises stomach acid
- makes conditions alkaline
53
Enzymes and Digestion -
In what conditions do the enzymes in small intestine work best?
alkaline
54
Enzymes and Digestion -
What does bile emulsifying fats mean?
Breaks fats into tiny droplets
55
Enzymes and Digestion -
What does bile emulsifying fats mean?
- gives much bigger surface area of fat for enzymes to work on (digestion faster)
56
Enzymes and Digestion -
Enzymes used in the digestive system are produced by specialised cells in ...
glands and the gut lining
57
Enzymes and Digestion -
What do salivary glands produce?
Amylase in saliva
58
Enzymes and Digestion -
What is produced in the liver?
Bile;
- neutralises stomach acid
- emulsifies fats
59
Enzymes and Digestion -
What is stored in the gall bladder?
bile before being released into the small intestine
60
Enzymes and Digestion -
What is the large intestine?
Where excess water absorbed from food
61
Enzymes and Digestion -
What does the stomach do?
1. pummels the food with its muscular walls
2. produces pepsin (protease enzyme)
3. produces hydrochloric acid
62
Enzymes and Digestion -
Why does the stomach produce hydrochloric acid?
- kill bacteria
- provide right pH for protease enzyme too work (pH 2 - acidic)
63
Enzymes and Digestion -
What does the pancreas produce and release?
Produces:
- protease
- lipase
- amylse
Releases:
protease, amylase, lipase into small intestine
64
Enzymes and Digestion -
What does the small intestine produce?
protease, amylase, lipase to complete digestion
65
Enzymes and Digestion -
What happens in the small intestine?
Where digested food absorbed out of digestive system into blood
66
Enzymes and Digestion -
What happens at the rectum?
Where faeces (mainly indigestible food) stored before exit through anus.
67
Food Tests - RP
How do you prepare a food sample?
1. Break up piece of food using pestle and mortar
2. Transfer ground up food to beaker + add some distilled water
3. Stir mixture with glass rod to dissolve some of the food
4.
Filter solution using funnel (lined with filter paper) - get rid of solid bits of food.
68
Food Tests - RP
What are the two types of sugars?
- non reducing
- reducing
69
Food Tests - RP
What is the test called for testing for reducing sugars and method?
Benedict's Test
Method:
1. Prepare food sample + transfer 5 cm cubed to test tube
2. Water bath set to 75 degrees Celsius
3. Add some Benedict's solution to the test tube (10 drops) using pipette
4. Place test tube in water bath using test tube holder + leave for 5 mins (test tube pointing away from you)
5. If food sample contains reducing sugars, solution in test tube change from blue colour to green, yellow or brick red (depending on how much sugar in food)
70
Food Tests - RP
How do you test for starch?
1. Make food sample + transfer 5 cm cubed of sample to test tube
2. Add few drops iodine solution + gently shake.
3. If sample contains starch colour change from browny- orange to black of blue - black.
71
Food Tests - RP
What do you use to test for proteins?
Biuret test
72
Food Tests - RP
How do you test for proteins?
1. Prepare sample of food + transfer 2 cm cubed of sample to test tube
2. Add 2 cm cubed of biuret solution to sample + gently shake
3. I food sample contains protein change from blue to purple
73
Food Tests - RP
What do you use to test for the presence of lipids in food using?
Sudan III stain solution
1. prepare sample of food (don't need to filter it) + transfer 5 cm cubed into test tube
2. Use pipette add 3 drops of Sudan III stain solution to test tube + gently shake
3. If sample contains contains lipids, mixture separate out into two layers (top brick red)
74
Food Tests - RP
What are the food test and the colour changes?
- Sugars - Benedict's Solution (blue to gree, yellow, brick red)
- Starch - Iodine solution (browny - orange to blue -black)
- Proteins - Biuret Solution (blue to purple)
- Lipids - Sudan III stain solution (separate into brick red top layer)
(all are for positive results)
75
The Lungs -
Where are the lungs and what does that mean?
Thorax - top part of your body
76
The Lungs -
What is the thorax separated from the lower body by?
Diaphragm
77
The Lungs -
What are the lungs protected by?
Ribcage
78
The Lungs -
What happens at the lungs?
1. Air you breathe goes in through the trachea.
2. Splits into two tubes called brochi (each one is a bronchus) one to each lung
3. The bronchi split into progressively smaller tubes called bronchioles
4. Bronchioles end at the alveoli where gas exchange takes
79
The Lungs -
What is the process of gas exchange in the alveoli?
1. Blood passing next to the alveoli (in blood capillaries) is deoxygenated (lots of CO2 + very little O2)
2. Oxygen in alveolus (high conc) diffuses into blood (low conc).
3. Carbon dioxide diffuses out blood (high conc) into alveolus (low conc) to be breathed out
4. When blood reaches body cells oxygen released from RBC (high conc) + diffuses into body cells (low conc)
5. At same time, CO2 diffuses out body cells (high conc) into blood (low conc) + carried to lungs
80
The Lungs -
What is the calculation of breathing rate in breaths per minute?
breaths per minute = number of breaths/ number of minutes
81
Circulatory System - The Heart:
What does the circulatory system do?
- carries food and oxygen to every cell in the body
- carries waste products to where they can be removed from the body
82
Circulatory System - The Heart:
What is the circulatory system made up of?
-heart
- blood vessels
- blood
83
Circulatory System - The Heart:
What type of circulatory system do humans have?
Double circulatory system (two circuits joined together)
84
Circulatory System - The Heart:
What does the first circuit of the double circulatory system do?
Right ventricle pumps deoxygenated blood to lungs to take in oxygen + blood then returns to heart
85
Circulatory System - The Heart:
What does the second circuit of the double circulatory system do?
Left ventricle pumps oxygenated blood around all the other organs of body + blood gives all oxygen to body cells + deoxygenated blood returns to heart to pumped to the lungs again
86
Circulatory System - The Heart:
What is the heart?
A pumping organ that keeps the blood flowing around the body
87
Circulatory System - The Heart:
What are the walls of the heart mostly made of?
Muscle tissue
88
Circulatory System - The Heart:
Why does the heart have valves?
Prevent blood flowing backwards
89
Circulatory System - The Heart:
How does the use it's 4 chambers to pump blood around?
1. Blood flows into the two atria from vena and pulmonary vein
2. atria contract (push blood into ventricle)
3. Ventricles contract force blood into pulmonary artery and aorta and out of the heart
4. Blood then flows to the organs through arteries + returns through veins
5. The atria fill again and cycle starts over
90
Circulatory System - The Heart:
What is the simple process of blood flow through the heart?
body --> Vena Cava --> right atrium --> valve --> right ventricle --> valve --> pulmonary artery --> lungs --> pulmonary vein --> left atrium --> valve --> left ventricle --> valve --> aorta --> body
91
Circulatory System - The Heart:
How does the heart get its own supply of oxygenated blood?
Arteries called coronary arteries branch off aorta + surround heart (meaning gets supply of oxygenated blood)
92
Circulatory System - The Heart:
What is your resting heart rate controlled by?
group of cells in right atrium wall that acts as a pacemaker
93
Circulatory System - The Heart:
What do the cells that act as a pacemaker produce?
small electric impulse which spread to surrounding muscle cell + cause them contract
94
Circulatory System - The Heart:
What is often used to control heartbeat if the natural pacemaker cells don't work properly?
Artificial pacemaker
95
Circulatory System - The Heart:
What is an example of when your natural pacemaker doesn't work properly?
irregular heartbeat
96
Circulatory System - The Heart:
What is an artificial pacemaker?
Device implanted under skin + has wire to heart + produces electric current to keep heartbeat regular
97
Circulatory System - Blood Vessels:
What are the three different types of blood vessels?
-Arteries: carry blood away from heart
- Capillaries: involved in exchange of material at tissues
- Veins: carry blood to heart
98
Circulatory System - Blood Vessels:
What is the structure of the arteries?
Blood at high pressure mean:
-walls strong + elastic
- thick walls compared to lumen
- thick layers of muscle to make them strong
- elastic fibres allow them stretch + spring back
99
Circulatory System - Blood Vessels:
What is the structure of capillaries?
-tiny
- permeable walls (substances diffuse in + out)
- walls one cell thick (increase rate of diffusion by decreasing distance)
- very small lumen
100
Circulatory System - Blood Vessels:
What is the function of capillaries?
- carry blood close to every cells in body to exchange substances with them
- supply food + oxygen
- take away waste CO2
101
Circulatory System - Blood Vessels:
Structure of veins?
- thinner walls than arteries (blood at lower pressure)
- bigger lumen (help blood flow despite low pressure)
- have valves (keep blood from flowing backwards)
102
Circulatory System - Blood Vessels:
What is the equation to calculate rate of blood flow?
rate of blood flow = volume of blood / number of minutes
103
Circulatory System - Blood:
What is blood?
A tissue
104
Circulatory System - Blood:
What are the four things that are in blood?
- red blood cells
- white blood cells
- platelets
- plasma
105
Circulatory System - Blood:
What is the job of red blood cells?
carry oxygen from lungs to all cells in body
106
Circulatory System - Blood:
What is the structure of red blood cells?
- biconcave disc: large surface area for absorbing oxygen
- no nucleus: allow more oxygen
- contain haemoglobin
107
Circulatory System - Blood:
What does haemoglobin do in the lungs?
binds to oxygen to become oxyhaemoglobin
108
Circulatory System - Blood:
What does haemoglobin do in body cells?
opposite to in the lungs:
oxyhaemoglobin splits into haemoglobin + oxygen and release oxygen to cells
109
Circulatory System - Blood:
What does having more red blood cells mean?
more oxygen can get to your cells
110
Circulatory System - Blood:
What happens to your production of red blood cells at high altitudes?
less oxygen so produce more red blood cells to compensate
111
Circulatory System - Blood:
What do white blood cells do?
defend against infection
112
Circulatory System - Blood:
What is the process called when some white blood cells change to engulf unwanted microorganisms?
phagocytosis
113
Circulatory System - Blood:
What do some red blood cells produces to fight microorganisms?
- Antibodies: to fight microorganisms
- Antitoxins: to neutralise nay toxins produced by microorganisms
114
Circulatory System - Blood:
What is a key difference in the structure of white blood cells and red blood cells?
white blood cells have a nucleus
red blood cells no nucleus
115
Circulatory System - Blood:
What is the function of platelets?
Help blood clot
116
Circulatory System - Blood:
What are platelets?
small fragments of cells with no nucleus
117
Circulatory System - Blood:
What do platelets do?
Help blood to clot around a wound - stop all blood pouring out + stop microorganisms getting in
118
Circulatory System - Blood:
What can a lack of platelets cause?
- excessive bleeding
- excessive bruises
119
Circulatory System - Blood:
What is plasma?
liquid that carries everything in the blood
120
Circulatory System - Blood:
What does plasma carry in the blood?
- red blood cells
- white blood cells
-platelets
- glucose + amino acids (nutrients) - soluble products of digestion absorbed from gut and taken to body
- carbon dioxide (from organs to lungs)
- urea (from liver to kidneys)
- hormones
- proteins
- antibodies + antitoxins (produced by white blood cells)
121
Cardiovascular Disease -
What is cardiovascular disease?
Disease of the heart or blood cells
122
Cardiovascular Disease -
What is an example of a cardiovascular disease?
Coronary heart disease
123
Cardiovascular Disease -
What is coronary heart disease?
When coronary arteries that supply blood to muscles of the heart become blocked by layers of fatty materials building up. Causing arteries to become narrow, so blood flow restricted and lack of oxygen to heart muscles
124
Cardiovascular Disease -
What can coronary heart disease lead to?
Heart attack
125
Cardiovascular Disease -
What are stents?
Tubes inserted inside arteries that keep them open by squashing fatty deposists
126
Cardiovascular Disease -
What are stents a way of doing?
Lowering risk of heart attack in people with coronary heart disease
127
Cardiovascular Disease -
What are the pros and cons of stents?
Pros:
+ effective for long time
+ recovery quickly
Cons:
- risk complications (from surgery)
- risk infection (from surgery)
- risk developing blood clots near stent (thrombosis)
128
Cardiovascular Disease -
What are statins + their purpose?
Drugs that can reduce amount of 'bad' cholesterol in bloodstream (slow down rate of fatty deposists forming)
129
Cardiovascular Disease -
What is cholesterol?
essential lipid body produces + needs to function
(too much of certain type eg LDL cholesterol can cause health problems)
130
Cardiovascular Disease -
What can having too much 'bad' cholesterol in bloodstream cause?
fatty deposits form in arteries (lead to coronary heart disease)
131
Cardiovascular Disease -
What are the pros and cons of statins?
Pros:
- reduce risk strokes, coronary heart disease, heart attacks
- increase amount beneficial type of cholesterol (HDL cholesterol) in bloodstream
- prevent some other diseases
Cons:
- taken regularly (could forget)
- can cause headaches, kidney failure, liver damage, memory loss
- effect isn't instant (time for effect to kick in)
132
Cardiovascular Disease -
What are two options for person with heart failure?
- heart transplant (donor hear)
- heart transplant (artificial heart)
- also sometimes lung transplant if lungs also diseased
133
Cardiovascular Disease -
What are donor hearts?
Hearts from a donor who has recently passed away
134
Cardiovascular Disease -
What are artificial heart?
Mechanical devices that pump blood for person whose own heart has failed
135
Cardiovascular Disease -
What are artificial heart usually used as?
- temporary fix to keep person alive until donor heart found
- help person recovery by allowing heart to rest and heal
- sometimes permanent fix reducing need for heart donors
136
Cardiovascular Disease -
What are the advantages and disadvantages of artificial hearts?
Advantages:
- less likely to be rejected than donor heart (made from metals or plastics so boy doesn't recognise them as foreign objects)
Disadvantages:
- surgery can lead to bleeding + infections
- don't work as well as healthy, natural heart (part could wear out or electrical motor could fail)
- blood doesn't flow as smoothly (lead to blood clots, strokes)
- patient take drugs to thin blood (can cause problems with bleeding if they are injured)
137
Cardiovascular Disease -
How can the valves in the heart be damaged or weakened?
- heart attacks
- infections
- old age
138
Cardiovascular Disease -
What can damage to valves cause?
- valve tissues to stiffen: won't open properly
- leaky: blood flow in both directions meaning blood doesn't circulate as effectively)
139
Cardiovascular Disease -
What can replacement valves be taken from?
Biological valves:
- humans
- other mammals (cows, pigs)
Mechanical valves:
- man made
140
Cardiovascular Disease -
Pros and cons of valve replacement rather than heart transplant:
Pros: less drastic than heart transplant
Cons: still major surgery (still cause blood clots)
141
Cardiovascular Disease -
What is artificial blood?
Blood substitute (eg salt solution - saline) used to replace lost volume of blood in accident
142
Cardiovascular Disease -
Pros and Cons of artificial blood:
Pros:
- safe (if no air bubbles)
- keep people alive even if lose two thirds of their blood
- give patient enough time produce new blood cells
-don't need blood transfusion
Cons:
- if not enough time to produce new blood cells, patient need blood transfusion
143
Cardiovascular Disease -
What is the ideal function of artificial blood products?
Replace function of lost red blood cells so no need for blood transfusion. (scientists currently working on this)
144
Health and Disease -
What is health?
State of physical and mental wellbeing
145
Health and Disease -
What are diseases often responsible for?
causing ill health
146
Health and Disease -
What are are the two types of diseases?
-Communicable: spread from person to person or between animals and people
- Non communicable: cannot be spread between people or between animals and people.
147
Health and Disease -
How are communicable and non communicable diseases caused and examples?
- Communicable: bacteria, viruses, parasites, fungi eg measles, malaria
- Non communicable: examples include asthma, coronary heart disease
148
Health and Disease -
Examples of when diseases interact and cause other physical and mental health issues:
1. weakened immune system have increase chance suffering from communicable diseases eg flu as body less able to defend itself against pathogens
2. some types of cancer triggered by infection by certain virsues eg infection from HPV can cause cervical cancer
3. Immune system reactions caused by infection can sometimes trigger allergic reaction eg skin rashes (or worsen symptoms for people with asthma)
4. mental health issues eg depression triggered if suffering severe physical health problems
149
Health and Disease -
What are factors other than disease that can affect health?
- balanced diet
- stress
- life situation eg access to medicines or access to prevent getting ill eg condoms prevent STDs
150
Risk Factors or Non - Communicable Diseases:
What are risk factors?
Things that link to an increase in the likelihood that person will develop certain disease during their lifetime (don't guarantee some get disease)
151
Risk Factors or Non - Communicable Diseases:
What are risk factors often?
- Aspects of person's lifestyle eg exercise
- substances in the environment eg air pollution
- substances in your body eg asbetous fibres (cause disease such as cancer in later life)
- many non communicable disease caused by several risk factors interacting rather than just one
152
Risk Factors or Non - Communicable Diseases:
Where can lifestyle factors have different impacts and examples:
Different impacts locally, nationally, globally.
Examples:
- developed countries disease more common has higher income and can but high fat food.
- nationally: deprived areas more likely smoke, have poor diet, no exercise (obesity, type 2 diabetes, cardiovascular disease higher in these areas)
- your individual choices affect local incidences of disease
153
Risk Factors or Non - Communicable Diseases:
What are some risk factors that are able to directly cause a disease?
- Smoking: cardiovascular disease, lung disease, lung cancers,( damages walls of arteries + cell lining in lungs)
- Obesity: type 2 diabetes (make body less sensitive? resistant to insulin mean struggle control blood glucose conc)
- Too much alcohol: liver disease, affect brain function (damage nerve cells in brain cause brain to lose volume)
- Smoking/ drinking alcohol when pregnant: health problems for unborn baby
- Cancer: exposure to certain substances/ radiation eg carcinogens such ionising radiation from an X ray
154
Risk Factors or Non - Communicable Diseases:
Correlation doesn't always equal...
cause
155
Risk Factors or Non - Communicable Diseases:
What are some risk factors unable to do and example?
directly cause disease.
Example:
- lack exercise + high fat diet linked to increased risk of cardiovascular disease but not cause (these lifestyle factors result in high blood pressure + high 'bad' cholesterol level which actually cause it)
156
Risk Factors or Non - Communicable Diseases:
How can non communicable diseases be costly?
- NHS researching + treating disease
- families may need to move/ adapt their homes
- family member with disease give up work/ dies lead to reduced income
- reduction in people working also reduce country's income
157
Cancer -
What is cancer caused by?
Uncontrolled cell growth and division
158
Cancer -
What is the uncontrolled cell growth and division a result of and what does it result in?
Changes that occur to the cell resulting in formation of a tumour
159
Cancer -
What is a tumour and the types:
Tumour = a mass of cells
Types:
- benign: tumour grows until no more room, stays in one place, doesn't invade other tissues in body, tumour non cancerous
- malignant: tumour grows + spreads to neighbouring healthy tissues, cells break off + spread to other parts of body by travelling through bloodstream, form secondary tumours, cancerous
160
Cancer -
What does having risk factors mean?
Increased risk of developing cancer (not definite)
161
Cancer -
Why have cancer survival rate increased?
-improved treatment
- diagnose earlier
- increased screening
162
Cancer -
What are lifestyle factors that are associated with certain cancers?
- Smoking: lung, mouth, bowel, stomach, cervical cancer
- Obesity: bowel, liver, kidney cancer
- UV exposure: skin cancer (due to using sun beds + outside a lot increased risk)
- Viral Infection: hepatitis B/C increased risk of liver cancer (likelihood becoming infected depend on lifestyle eg unprotected sex or sharing needles)
163
Cancer -
What can risk factors also be associated with and why?
Genetics:
- inherit fault genes that make you more susceptible eg mutations in BRCA genes increase risk developing breast and ovarian cancer
164
Plant Cell Organisation -
What are plants made up of?
-organs
-tissues
165
Plant Cell Organisation -
What are examples of plant organs?
-stems
- roots
- leaves
166
Plant Cell Organisation -
What are examples of plant tissues?
- epidermal tissue: covers whole plant
- palisade mesophyll tissues: part of leaf where most photosynthesis occurs
- spongy mesophyll tissue: part of leaf, contains big air sacs allow gases diffuse in + out cells
- Xylem + phloem: transport water, mineral ions, food around plant
- Meristem tissue: growing tips of shoots and roots (can differentiate into different types of plant cells mean plant grow)
167
Plant Cell Organisation -
What types of tissues do leaves contain?
- epidermal
- mesophyll
- xylem
- phloem
168
Plant Cell Organisation -
What are the structures of the tissues that make up the leaf and how are they related to their function?
1. epidermal tissue covered in waxy cuticle, helps reduce water loss by evaportation
2. upper epidermis - transparent so light pass through to palisade layer
3. palisade layer lots of chloroplasts - near top of the leaf where most light
4. xylem + phloem adapted for efficient gas exchange - deliver water + nutrients to entire leaf + take away glucose produced by photosynthesis - support structure
5. tissues of leave adapted for efficient gas exchange - lower epidermis full of stomata (let CO2 diffuse directly into leaf), guard cells control opening + closing of stomata.
169
Plant Cell Organisation -
What do the air spaces in spongy mesophyll tissue increase?
rate of diffusion of gases
170
Transpiration and Translocation -
What are phloem tubes?
Columns of elongated living cells with small pores at the end walls (allow cell sap flow through)
171
Transpiration and Translocation -
What do phloem transport?
Food substances (mainly dissolved sugars) made in leaves to rest of plant for immediate use (growing) or storage
172
Transpiration and Translocation -
In which direction do phloem transport food substances?
Both directions
173
Transpiration and Translocation -
What is the process that occurs in the phloem?
Translocation
174
Transpiration and Translocation -
What is the structure of xylem tubes?
Dead cells joined end to end with no end walls and a hole down the middle
175
Transpiration and Translocation -
What are the xylem strengthened with?
Lignin
176
Transpiration and Translocation -
What do xylem tubes do?
Carry water and mineral ions from roots to stem and leaves
177
Transpiration and Translocation -
What is the movement from the roots, through the xylem and out of the leaves called?
Transpiration stream
178
Transpiration and Translocation -
What is transpiration caused by?
Evaporation + diffusion of water from plant's surface
179
Transpiration and Translocation -
Where does most transpiration occur?
Leaves
180
Transpiration and Translocation -
What does the evaporation in the leaves cause?
Slight shortage of water in leaves, so more water drawn up from rest of plant through xylem vessels to replace it
181
Transpiration and Translocation -
What does the evaporation of water in leaves meaning more water needed to be drawn up from roots cause there to be?
Constant transpiration stream (of water through the plant)
182
Transpiration and Translocation -
How does the water escape through the stomata?
diffusion
183
Transpiration and Stomata -
What are the four main things that transpiration rate is affected by?
- light intensity: brighter = greater transpiration rate, stomata close as gets dark so photosynthesis can't occur so don't need to be open means very little water can escape
- temperature: warmer = faster transpiration (more energy to evaporate + diffuse out of stomata)
- air flow: better air flow around leaf = greater transpiration rate, low conc of water outside if good air flow mean diffusion faster
- humidity: drier air around leaf = faster transpiration (less water outside leaf so faster rate of diffusion)
184
Transpiration and Stomata -
How can you estimate the rate of transpiration + method?
Measure uptake of water from plant
Method:
1. set up apparatus as diagram states on page 44 of text book
2. record starting position of air bubbles
3. start stopwatch + record distance moved by bubbles per unit of time (eg per hour)
4. Keep conditions constant: temperature + air humidity
185
Transpiration and Stomata -
What is the structure of a guard cell?
- kidney shape
- thin outer walls (make opening and closing work)
- thick inner walls (make opening and closing work)
186
Transpiration and Stomata -
What is the purpose of guard cells?
to open and close stomata
187
Transpiration and Stomata -
What happens to the guard cells when the plants have lots of water?
guard cells fill with the water and become turgid making the stomata open - means gases can exchange for photosynthesis
188
Transpiration and Stomata -
What happens to guard cells when the plants are short of water?
guard cells lose water and become flaccid making stomata close - helps stop too much water vapour escaping
189
Transpiration and Stomata -
What happens to guard cells at night?
Close (sensitive to light)- save water without losing out on photosynthesis
190
Transpiration and Stomata -
Where are more stomata found?
Underside of leaves - lower surface shaded and cooler (less water lost through stomata than if on upper surface)
191
Transpiration and Stomata -
What are guard cells adapted for in the leaf?
- gas exchange
- controlling water loss
