Organisation Flashcards
(124 cards)
1
Q
What are the levels of organisation in organisms, from least complex to most complex?
A
Organelles ➔ cells ➔ tissues ➔ organs ➔ organ systems
2
Q
What is a tissue?
A
A group of similar cells working together to perform a common function
3
Q
What is the definition of an organ?
A
A group of similar cells working together to perform a common function
4
Q
Explain, using an example, why the digestive system is considered an ‘organ system’.
A
The digestive system is considered an organ system because it consists of a group of organs…
…that work together to perform the common function…
…of digesting and absorbing our food (this mark is for describing the function of the system)
For example the pancreas releases digestive enzymes which help break down the food molecules, while the small intestine absorbs the nutrients (this mark is for giving an example of how the individual organs help - 1 example would be fine).
5
Q
what does the epitherial tissue do
A
covers the body’s surface
6
Q
what does the muscular tissue do
A
contract and relaxes
7
Q
what does the glandular tissue do
A
makes and secrets hormones
8
Q
what is stomach’s function
A
Has a function of killing mirco organisms and breaking down protein
9
Q
What is a function of tissue
A
A group of similar cells that works togheter to carry that work togheter to carry out a particular function.
10
Q
What is an organ
A
A group of different tissues that work togheter to preform a particular function.
11
Q
what is the defenition of communicable disease and an example
A
Communicable diseases can be spread from person to person eg measles
12
Q
how are communicable disease spread
A
by pathogens such as bacteria or viruses
13
Q
what is the defenition of non-communicable disease and an example
A
these cannot be passed from person to person eg.coronary heart disease
14
Q
wha is the defenition of health
A
health is defined as the stateof physical and mental well-being.
15
Q
what are the causes of ill health
A
communicable
non- comminable diseases
poor diet
high levels of stress
life situations eg working w chemicals
16
Q
what is TB
A
tuberculosis (TB) is a communicable lung disease and it can be fatal
17
Q
what people get TB
A
Most peoples immune system can figth of TB however some people have a defective immune system for eg poeple with HIV
People with defective immune system are much more likely to suffer from infectious diseases
18
Q
what is HPV
A
Human papilloma virus is extremely common.In most people it is essentially harmless
in some people HPV can cause cervical cancer
19
Q
Explain cervical cancer
A
Around 3000 women are diagnosed with cervical cancer in UK
Most cervical cancer are cause by HPV which infects the cells of the cervix
20
Q
explain allergies
A
sometimes a disease can be triggered by an immune system eg allergies such as asthma or dermatitis
in this case the body is infected with a pathogen which the immune system can fight off but the person is then left with an allergy
21
Q
how can mental illness be triggered by a phycical illness
A
people with arthritis find it very difficult to move and lead a normal life.
In certain cases this can make them feel isolated and depressed.
22
Q
what is Epidemiology
A
Study of the patterns of disease to determine risk factors is called epidemiology
23
Q
what si a corroletion between the risk of devoloping li=ung cancer and number of cigarettes smoked per day
A
As the number of ciggarretes smoked per day increase the risk of developing a lung cancer increase too, this is called positive correlation
24
Q
what si a causual mechanism
A
The processes or pathways through which an outcome is brought into being.
eg HOW does smoking causes lung cancer
25
how does smoking cause lung cancer
They discovered that cigarette smoke contains chemical which damage DNA and increase the risk of cancer
these are called carcinogens
26
what is sampling
Scientist sampe a group of people and then try to draw conclusions about the whole population
27
how to avoid bias when sampling
we need to take as large a sample as possible and it must be as random as possible
28
what are the causes of cardiovascular diesase
- a diet that is high in fat nad low in veggies incease the levels of certain types of cholesterol in the blood.This increases the rate that fatty materials build up in the arteries
- A diet high in salt can increse blood pressure increasing the risk of developing cardiovascular diseases
- the risk od developing these diseases is also massively increased in people who smoke
29
what are risk factors of lung cancer
- smoking massively increases the risk of lung cancer
- cigarette smoke contains a number or chemicals which can trigger cancers (eg carcinogens)
30
effects of smoking on an unborn baby
smoking when pregnant increases the risk of miscarriage and premature birth
It can also lead to the baby being born with a low body mass
31
effects of drinking on unborn baby
drinking alcohol when pregnant can cause fetal alcohol syndrome
children with this syndrom can have learning difficulties and other mental or physical problems
32
effects of drinking on an adult
Adults who drink alchohol excessively increase their risk of liver cirrhosis and liver cancer
it can aslo affect the brainleading to addiction and memory loss
33
what is type 2 diabetes and what are its effects
people who have type 2 diabetes struggle to control their blood glucose levels
it can lead to blindness or reqire the amputation of a limb
34
what people have a higher chance of developing type 2 diabetes
obese people have a much higher risk of developing type 2 diabetes
35
show how risk factors can interact
drinking excess alcohol can lead to obesity and then that increase the risk of type 2 diabetes
36
what is the top and the bottom of the leaf are covered in
The top and bottom of the leaf are covered with a layer of very thin cells, These are called epidermal cells and they form epidermal tissue = lower and upper epidermis
The epidermis protects the surface of the leaf
37
explain upper epidermises function and characteristics
The upper epidermis is transparent this allows light to pass thought to the photosynthetic cells below
it is also covered in a thin layer of oily material callled waxy cuticle
38
why is waxy cuticle needed
it reduces the evapuration of water from the surface of th leaf This helps to prevent the leaf from drying out
39
what is found at lower epidermis
the lower epidermis has tiny pores called stomata,
40
why is stomata needed
Stomata allows CO^2 to enter the leaf and oxygen to leave
And it also helps to control the amount of water vapour that pass out of the leaf
on either the isde of stomata we find guard cells
41
what is palisade mesophyll
The palisade mesophyll consists of palisade cells, which are packed full of choroplasts
42
what is chloroplast
chloroplast caontain chlorophyll whcih absorbs the light energy needed for photosynthesis
43
what is spondy mesophyll and its purpose
the spongy mesophyll is full of air spaces.These air soaces allow CO2 to diffuse from the stomata thought the spongy mesophyll to the palisade cells
oxygen also diffuses from the palisade cells thought the spongy mesophyll to the stomata.
44
what id a purpose of xylem tissue
Xylem tissue transports water from the roots to the stem and the leaves
It also transports dissolved mineral ions these include magnesium which used to make chlorophyll
45
what is a phloem tissue and what si its purpose (talk abt sugars)
phloem tissue transports dissolved sugars produced by photosynthesis from the leaves to the rest of the plant
these sugars can be used immediatly eg glucose is used in respiration
others can be stored eg as starch
46
what is translocation
the movement of sugars and other moleculeas thought phloem tissue is called translocation
Phloem unlike xylem is living tissue. Its job is to move sugars made during photosynthesis from the leaves all over the plant to where it is needed for growth. Food is also transported to storage organs where it provides an energy store for the winter
47
what is meristem tissue
we find it at growing tips eg shoots and roots
this tissue contain stem cells these can differentiate into different types of plant tissue
48
how does water enters the plant
thought root hair cells and xylem
49
what is transpiration
water is constantly evapurating from the surfaces of leaves.
50
what s a transpiration stream
Transpiration starts with th evaporation of water from the leaf.The water vapour then diffuses thought the air spaces in the spongy mesophyll and out of the leaf thought the stamata.Now water passes from the xylem into the leaf to replace the water that has been lost.Fianlly water is drawn into the root hair cells and up the xylem vessels to the leaf
51
why are transpiration streams very important from the plant
- it brings plant water that it reqiures for photosystesis
-it transport dissolved mineral ions eg magnesium
- evapuration of water cools the leaf down (important escp. in hor weather)
52
transpiration and SA increses, how does it affect water uptake and what potometer test is required
Because rate of diffusion from leaf increases.
More leaf SA = more stomata to open
Vaseline on lower surface
53
transpiration and tempreture increses, how does it affect water uptake and what potometer test is required
Because rate of diffusion from leaf increases due to water molecules having more Kinetic energy.
Plant placed in a warm room
54
transpiration and increase in air movement - increses, how does it affect water uptake and what potometer test is required
Because rate of diffusion from the leaf increases due to increased concentration gradient
Fan pointed at plant
55
transpiration and light intesity - increses, how does it affect water uptake and what potometer test is required
Because rate of diffusion from leaf increases as stomata open for photosynthesis.
Lamp directed at lower surface of leaf
56
how does the stomatas work
When the light intensity os high for example duirng the day the guard cells swell and they change their shape.This causes the stomata to open.Now CO2 can diffuse into the leaf and he used in photosynthesis.Under hot conditions the plant closes its stomata to reduce water loss by transpiration.That now means that the plant cannot photosynthesis.
57
what are properties of muscle cellsand tissue
they can contract due to special protein fibres that they contain which can change their lenght.
They are also packed full of mitochondria which provides the enrgy needed for contraction
58
what is first step in a digestion process
first food is chewed in the mouth.Enzymes in the saliva begin to digest the strach into smaller sugar molecules.
59
what is the second step of digestion
the food then passed down the oesophagus into the stomach
60
what is the third step of digestion
In the stomach enzymes begin the digestion of protein
(the stomach aslo contains HCl acid which helps digesting proteins)
61
Food in the stomach
food spends several hours in the stomachthe churning action of the stomach muscle turns the food into a fuid increasing the surface area for enzymes to digest
62
what is the fourth step of digestion
the fluid now past into the small intestine
63
what is the fifth step of digestion
at this point chemicals are released into the small intestine from liver and pancrese
the walls of the small int release enzymesto continue the digestion of proteins and lipids
64
pancrease in digestion
the pacnrease releases enzymes which continue the digestion of starch and proteinn.They also start the digestion of lipids.
65
liver in digestion
the liver releases bile whch helps to speed up the digestion of lipids Bile also neutrializes the acid release from the stomach
66
what is the six step of digestion
In the small int, the small food molecules produced by digestion are absorbed into the bloodstream either by diffusion or by active transport
67
what is the seven step of digestion
now the fluid makes its way thought the large int. where water is absorbed into the bloodstream
Last the feeces is released from body
68
what is glucose needed for
respiration
69
lock and key theory
enzymes are specific, the substrate must fit perfectly into the active site
70
what enzyme breaks down proteins
protease
71
where is protease produced
stomach oancrease nad small intestine
72
how does protein digestion works
proteins are long chains of amino acids.When we digest proteins, protese enzymes convert the protein back to the individual amino acid , which are then absorbed into the blood stream.When the amino acids are absorbed by the body cells they are joined togheter ina different order to make human preteins.
73
How does starch digestion works
starch consists of a chain of glucose molecules.carbohydrates are broken down by enzymes called carbohydrase.In the case of starch this is called amylase.When carbon like starch are digested we produce simple sugars.
74
where is amalyse found
in saliva and pancreatic fluid
75
where do we find lipase
in pancrese and small intestine
76
what are lipase molecules consists of
A lipid molecule consists of a molecule of glycerol attached to three molecules of fatty acids
77
how are lipids digested
lipids molecules are diagnosted by the enzymes lipase.This produces glycerol and fatty acids
78
what is bile
bile is made in liver and it is stored in the gall blader.Bile helps to speed up the digestion of lipids but bile is not an enzyme.
Bile converts large lipids droplets into smaller droplets
"BILE EMULSIFIES FAT"
this mainly increasesthe surface area of the lipid droplets
this increases the rate of lipids breakdown by lipase
79
what does bile do to the stomach acid
bile is an alkali - it neutralise acid in stomach , creating alkali conditions in the smal int
80
explain why does the temp increase increases the activity of the enzyme
As the tempratures increase the enzymes and substrate are moving faster so there ar emore collisons per second between the subtrate and the active site.
81
what is the optium tempreture
At a certain temp the enzyme is working at the fastest possible rate.At this point the maximum frequence of successeful collisions between the substrate and the active site.
82
what happens to an enzyme if the tempreture is too high
the enzyme molecules vibrate and the shape of the active site changes.Now the substarte no longer fits perfectly into the active site the active site is denatured The enzyme is no longer a catalyst
83
How does the pH affects the enzyme's activity
each enzyme has an optimum pH.Where the activity is maximum.If we make the PH more acidic or more or more alkali then the activity drops to 0.The active sitw is then denatures.
Protees = acidic pH
Lipase = alkali pH
84
what are 3 firts steps you need to take before a food test
1. Take the food sample and grind this with distilled water using a mortar and pestile.We want to make a paste
2.Transfer the paste to a beaker and add more distilled water.Stir so the chemicals in the food dissolved in the water.
3.Filter the solution to remove suspended food particles
85
food test for starch (include the name of solution, processs and result)
Place 2cm3 of food solution into a test tube.
Then add iodine solution in with orange colour.if starch is present then the iodine solution will turn blue- black
86
food test for suagrs (include the name of solution, processs and result)
Place 2cm3 of food sol in to a test tube
add 10 drops of benedict's solution which is a blue clour.Place tube containing the solution into a beaker with boiling water.
leave it for 5 min, if sugars are present the benedicts solution will change colour.
green = small amount of sugars
yellow = more sugars
red = a lot of sugar
87
limitations of benedict
Benedict sol only works for reducing sugars (e.g. glucose) it does not work for non - reducing (e.g sucrose)
88
food test for proteins(include the name of solution, processs and result)
... And we add 2cm3 of buriet sol which is a blue colour to the food sol If protein is present then the sol will turn from blue to purple /liliac
89
food test for lipids (include the name of solution, processs and result)
crush up the food but do not filter the solution (molecule can stick to paper)
when transfer 2cm3 of sol into a tube we add few drops of distilled water and a few drops of ethanol.We then gently shake the solution If lipids are present then a white cloudy emulsion forms
90
describe the expirement to find out the pH of amalyse
1.Place one drop of iodine solution into each well of a spotting tile
2.Add 2cm3 starch sol into 1st test tube into 2nd all 2cm3 of amalyse sol and last add pH5 buffer sol
3.Place all three test tubes in a water bath at 30 C leave them for 10 min to allow the solutions tor each the correct temp
4.Now combine the tree sol into one test tubes and mix with a string rod.Return to the water bath and start stopwatch
5.After thirty seconds use the string rod to transfer one drop of sol to a will in the spotting tile which contains iodine.
6.We now take a sample every thirty sec and we continue until the iodine remains orange
7.When the iodine remains orange this tells us that stach is no longer present (the reaction has completed)
8.We now repead the whole expiriment several times using different pH buffers for example pH 6, 7, and 8.
91
name 2 problems with the amalyse pH expiriment
1. We only have an approximate time for the reaction to omplete.Because we only take samples every 30 sec = we could solve this by taking samples every ten second
2.The colour change tends to be very gradual.Some wells might have a small amount of blue - black mixed with orange so it can be difficult to tell = to solve this let multiple popel look at it and decide
92
lenght of small int and its property
it is 5 m long
this provides a very large SA for absorbtion of the products of digestion
the interior of it is covered in millions of villi
93
what are properties of villi
the villi massivly increase the Sa for the absorbtion of molecules
Microvilli increase SA even further
94
Properties of villi
Inside the villi there are capillaries, so the villli have a very good blood supply so the bloodstream rapidly removes the produces of digestion.
Thsi increases the concentration gradient the thin membrane ensures a short diffusion path.All of these features mean that there is a rapid rate of diffusion
95
difference between oxygenated x deoxygenated blood
1.Deoxygenated blood flows into the right atrium and then into the right ventricle whcih pumps it to undergo gaseous exchange
2.Oxygenated blood flows into the left atrium and then into the left ventricle which pumps oxygenated blood around the body
96
what are 5 facts about the structure of the heart
● Muscular walls to provide a strong heartbeat
● The muscular wall of the left ventricle is thicker because blood needs to be pumped all around the body rather than just to the lung like the right ventricle.
● 4 chambers that separate the oxygenated blood from the deoxygenated blood
● Valves to make sure blood does not flow backwards
● Coronary arteries cover the heart to provide its own oxygenated blood supply
97
what is the process happening in our heart
1. Blood flows into the right atrium through the vena cava, and left atrium through the pulmonary vein.
2. The atria contract forcing the blood into the ventricles.
3. The ventricles then contract, pushing the blood in the right ventricle into the pulmonary artery to be taken to the lungs, and blood in the left ventricle to the aorta to be taken around the body.
4. As this happens, valves close to make sure the blood does not flow backwards.
98
how is the natural resting heart rate controlled by pacemakers
they provide stimulation through small electrical impulses which pass as a wave across the heart muscle, causing it to contract. Without this, the heart would not pump fast enough to deliver the required amount of oxygen to the whole body.
99
arteris
Arteries carry blood AWAY from the heart
● Layers of muscle in the walls make them strong
● Elastic fibres allow them to stretch
● This helps the vessels withstand the high pressure created by the pumping of the heart
100
veins
Veins carry blood TOWARDS the heart
● The lumen (the actual tube in which blood flows through) is wide to allow the low pressure blood to flow through
● They have valves to ensure the blood flows in the right direction
101
Capillaries
Capillaries allow the blood to flow very close to cells to enable substances to move between them
● One cell thick walls create a short diffusion pathway
● Permeable walls so substances can move across them
102
what are 6 organ of gas exchange system
● Trachea (the windpipe, air moves through here)
● Intercostal muscles (which contract and relax to ventilate the lungs)
● Bronchi (air from the trachea move into these, lead to each lung)
● Bronchioles (bronchi split into these and air moves in)
● Alveoli (bronchioles lead to the alveoli, air sacs where gaseous exchange occurs)
● Diaphragm (separates the lungs from the digestive organs, moves down causing inhalation)
103
explain how the ventilation works
1. The ribcage moves up and out and the diaphragm moves down causing the volume of the chest to increase.
2. Increased volume results in lower pressure.
3. Air is drawn into the chest as air moves from areas high pressure (the environment) to low pressure (the lungs).
4. The opposite happens when exhaling.
104
name 3 adaptation of alveoli
● They are very small and arranged in clusters, creating a large surface area for diffusion to take place over
● The capillaries provide a large blood supply, maintaining the concentration gradient
● The walls of the alveoli are very thin, meaning there is a short diffusion pathway
105
how to calculate breathing rate
by dividing the number of breaths by the number of minutes.
106
how does gas exchange works
1. Upon inhalation, the alveoli fill with oxygen.
2. The blood in the capillaries surrounding the alveoli is deoxygenated (ithas come from the pulmonary vein). It has lots of carbon dioxide as this is a product of respiration.
3. Oxygen diffuses down its concentration gradient into the capillary bloodstream, which has a low concentration of oxygen.
4. Carbon dioxide diffuses down its concentration gradient from the blood to the alveoli
107
plasma
his is liquid that carries the components in the blood: red blood cells, white blood cells, platelets, glucose, amino acids, carbon dioxide, urea, hormones, proteins, antibodies and antitoxins
108
red blood cells
● They carry oxygen molecules from the lungs to all the cells in the body
● Their bioconcave disc shape provides a large surface area
● They have no nucleus allowing more room to carry oxygen
● They contain the red pigment haemoglobin, which binds to oxygen and forms oxyhaemoglobin
109
White blood cells
● They are a part of the immune system, which is the body’s defence against pathogens (microorganisms that can produce disease)
● They have a nucleus
● There are a number of types:
○ 1- Those that produce antibodies (small proteins that clump them together) against microorganisms
○ 2- Those that engulf and digest pathogens ○ 3- Those that produce antitoxins to neutralise toxins (poisons) produced by microorganisms
110
Platelets
● They help the blood clot form at the site of a wound
● The clot dries and hardens to form a scab, which allows new skin to grow underneath while preventing microorganisms from entering
● Small fragments of cells
● No nucleus
● Without them, cuts would result in excessive bleeding and bruising
111
Coronary heart disease, or CHD
This is when the coronary arteries that provide blood to the heart become blocked with the build up of fatty material. This results in less blood flowing to the heart, reducing its oxygen supply. This may lead to a heart attack. (Non-communicable = non-infectious)
112
Stents as a solution
Stents (metal mesh tubes inserted in arteries) - keeps the arteries open to allow blood to flow through.
✓ They are effective in lowering the risk of a heart attack
✓ The recovery time from surgery is quick Risk of a heart attack during the procedure, or that infection could occur following it. There is a chance that blood clots can form near the stent (called thrombosis)
113
Statins as a solution
● Statins (drugs that decrease the levels of LDL (bad) cholesterol- which would otherwise lead to coronary heart disease)
✓ They reduce the risk of strokes, coronary heart disease and heart attacks
✓ They increase the levels of HDL (good) cholesterol Need to be taken continuously which may be an inconvenience Can produce side effects May not have an immediate effect as it only slows down the rate it is deposi
114
Faulty valves (problems)
when a heart valve becomes stiff so cannot open or it is damaged so it leaks, blood flows in the wrong direction which means that the heart does not work as efficiently as it should
115
solutions for faulty valves
● Replacing it with a biological valve (pigs or cattle)
✓ Works very well Only last 12-15 years
● Replacing it with a mechanical valve (manmade)
✓ Last for a long time Constant medication is needed to stop blood from clotting aroud the valve
116
heart failure solution (problems)
A heart transplant requires a donor who has recently died
● These are not always available, so an artificial may be used whilst waiting
✓ Less likely to be rejected by the immune system- metal and plastic are not recognised as foreign
Surgery temporarily leaves the body exposed to infection
As it is mechanical parts of it could wear out and the motor could fail
Blood clots could form, leading to strokes
To prevent the above, drugs are taken to thin the patients blood- this affects the individuals bleeding if they are hur
117
Extreme blood loss (problem)
● It is a salt solution that can keep people alive even if they lose ⅔ of their red blood cells
✓ This means the patient has more time to produce new blood cells
But it can only be used for short periods of time- then a blood transfusion has to take pl
118
what is a cancer
Cancer is the result of changes in cells that lead to uncontrollable growth and division, forming a tumour. This tumour may not be cancerous.
119
what bening tumor
- growths of cells contained in one place, usually within a membrane
● Not cancerous
● It grows until there is no more room
● It does not invade other tissues
● If it causes pressure or damage to an organ, it can be dangerous
120
what is malignant tumor
the tumour grows and spreads to other tissues
● Cancerous
● The tumour may split up, resulting in cells being carried in the bloodstream or lymphatic system
● They can travel to and stay in another organ, potentially causing secondary tumours
● The cancer cells divide more rapidly and have a longer life span in comparison to normal cells
121
name 5 lifestyle risk factors for cancer
● Smoking (lung, mouth, bowel, stomach and cervical cancer)
● Obesity (bowel, liver and kidney cancer)
● UV light (skin cancer)
● Viral infection (liver cancer from hepatitis B and C, cervical cancer from HPV) Genetic risk factors for cancer:
● You can inherit certain genes which increase the likelihood of getting cancer
122
Increase in humidity - decrease why and test
Because rate of diffusion from the leaf decreases due to decreased concentration gradient
Plastic bags over the whole plant
123
xylem
Type of transport
Substances transported
Direction of transport
Physical process
Water and minerals
Upwards
124
phloem
Type of transport
Substances transported
Direction of transport
Requires energy
Products of photosynthesis, including sugars and amino acids dissolved in water
Upwards and downwards
