Topic 2 Flashcards
(165 cards)
1
Q
What is a cell? (3 marks)
A
A basic building block that make up all living organisms.
2
Q
What is the name by which specialised cells carry out a function? (1 mark)
A
DIfferentiation
3
Q
When does differentiation occur? (2 marks)
A
The development of a multicellular organism
4
Q
Specialised cells form what? (1 mark)
A
Tissues
5
Q
What do tissues form? (1 mark)
A
Organs
6
Q
What do organs form? (1 mark)
A
Organ systems
7
Q
True or false: a tissue can only be made from one type of cell (1 mark)
A
False - a tissue can be formed from many cells, although they must be similar
8
Q
What is the use of musclular tissue? (2 mark)
A
Contracting to move what it’s attached to
9
Q
What is the use of glander tissue? (2 marks)
A
Making chemicals such as enzymes and hormones
10
Q
What is the use of epithermal tissue?
A
Covers parts of the body, such as the inside of the gut
11
Q
What is an organ? (1 mark)
A
A group of different tissues that work together to perform a certain function
12
Q
What is an organ system? (1 mark)
A
A collection of organs that work together to perform a particular function
13
Q
Name the organs in the organ system: the digestive system (5 marks)
A
Glands (pancreas and salivary gland) which produce juices; the stomach and small intestine, which digest food; the liver, which produces bile; large intestine, which absorbs water from indigested food
14
Q
The bladder is an organ. Explain what this means. (2 mark)
A
It is a collection of tissues, which is a collection of animal cells
15
Q
Starch proteins and fats are big ____, too big to pass through the walls of the ____ system, and break into smaller molecules like _____. (3 marks)
A
1) molecules, 2) digestive, 3) sugar
16
Q
Amylase is an example of what? (1 mark - extra mark for what it does)
A
A carbohydrase - it breaks down startch
17
Q
What are the three places where amylase is made (3 marks)
A
The salivary glands, the pancreas, the small intestine
18
Q
Proteases break down what? (1 mark)
A
Proteins
19
Q
Where is protease made? (3 marks)
A
The stomach (pepsin), the pancreas, the small intestine
20
Q
What does lipase convert lipids into? (2 marks)
A
Glycerol and fatty acids
21
Q
Where are lipases made? (2 makrs)
A
The pancreas, small intestine
22
Q
Bile is produced where? (1 mark)
A
In the liver
23
Q
Where is bile stored before it is released into the small intestine? (1 mark)
A
Gall bladder
24
Q
Hydrocloric acid makes the pH in the stomach too ____
A
acidic
25
Is bile alkaline or acidic? (1 mark)
alkaline
26
The enzymes in the small intestine work best in what conditions?
alkaline
27
Bile breaks fat into tiny droplets (emulsifies them), with gives a much bigger ______ for the lipase to work on, which makes digestion \_\_\_\_
1) surface area, 2) faster
28
Bile is a product of the liver. Describe and explain its role in digestion. (4 marks)
Bile is alkaline, so it neutralises the stomach acid and makes conditions in the small intestine alkaline. The enzymes of the small intestine work best in these alkaline conditions. It also emulsifies fats into tiny droplets. This gives a bigger surface area of fat to work on, making digestion faster.
29
What make chemical reactions work? (1 mark)
enzymes
30
Why do chemical reactions need to be carefully controlled? (1 mark)
to get the right amounts of substances
31
Does raising the temprature speed up a chemical reaction, or does it slow them down? (1 mark)
It speeds up the chemical reactions
32
Name two downsides of raising temperatures of chemcial reactions and speeding them up (2 marks)
It damages the cell if you raise the temperature too high, and the heat speeds up both the useful and unwanted chemical reactions
33
What do enzymes do? (2 marks)
Reduce the need for high temperatures, which is their only purpose as biological catalysts
34
What is a catalyst?
A substance that increases the speed of a reaction without being changed or used up
35
Enzymes are large ____ and all proteins are made up of chains of ____ acids. These chains are folded into unique shapes, which ____ need to do their jobs.
1) proteins, 2) amino, 3) enzymes
36
What does every enzyme have and what does it have?
An active site with a unique shape that fits onto the substance involved in a reaction
37
True or false: enzymes catalyse all reactions
False, most enzymes catalyse only one specific reaction.
38
What has to fit into its active site for an enzyme to work? (1 mark)
substrate
39
What is induced fit model of enzyme? (2 marks)
The active site changes shape a little as the substrate binds into it to get a tighter fit.
40
Like with any reaction, a higher temperature increases the ____ at first. But if it gets too hot, some of the ____ holding the enzyme together ____ (3 marks)
1) rate, 2) bonds, 3) break
41
Changing temperature changes the rate of what? (1 mark)
An enzyme-catalysed reaction
42
Will the substrate fit if the active site's shape changes? (1 mark)
No
43
If pH is too high, what will happen? (3 marks)
the pH will interfer with the bonbs holding the enzyme together. This changes the shape of the active site and denatures the enzyme.
44
What is usually the apt pH for most enzymes to work? (1 mark)
neutral pH 7
45
What is pepsin's best pH level? (2 marks)
pH 2 - which means it's well suited to acidic conditions
46
Explain why enzymes have an optimum pH (2 marks)
if the pH is too high or too low, it can interfere with the bonds holding the enzyme together. This changes the shape of the active site and denatures the enzyme.
47
What is starch easiest to detect with? (1 mark)
iodine solution
48
if starch is present, what colour will the iodine solution change to and from? (2 marks)
Browny-orange to blue-black
49
How do you investigate amylase activity? (8 marks)
1) put a drop of iodine solution into every well of spotting tile. 2) blace a Bunsen burner on a heat-proof mat, and a tripod and gauze over the Bunsen burner. Put a beaker of what on top of the tripod and heat the water until it is 35 degrees celcius. Keep temperature of the water contant throughout. 3) use a syringe to add 1 cm3 of amylase solution and 1 cm3 of a buffer solution with a pH of 5 to a boiling tube. Using test tube holders, put the tube into the beaker of water and wait for five minutes. 4) next, use a different syringe to add 5 cm3 of a starch solution to the boiling tube. 5) immediately mix the contents of the boiling tube and start a stop clock. 5) use cointinuous sampling to record how long it takes for the amylase to break down all of the starch. To do this, use a dropping pipette to take a fresh sample from the boiling tube every 30 seconds and put a drop into a well. When the iodine solution remains browny-orange, starch is no longer present. 7) repeat the whole experiment with buffer solutions of different pH values. 8) remember to control any variable each time to make it a fair test.
50
It's often useful to calculate the rate of reaction after an experiment. But what is rate? (1 mark)
Rate is a measure of how much something changes over time.
51
What is the formula for rate? (2 marks)
1000/time
52
Using the formula rate=1000/time, figure out the rate of reaction to 2 significant figures using the following results. (3 marks)
At pH 6, the time taken for amylase to break down all of the starch in a solution was 90 seconds.
1000/90=11s-1 (2 s.f.)
53
An enzyme-controlled reaction was carried out at pH 4. After 60 seconds, 33 cm3 of the product has been released. Calculate the rate of reaction in cm3/s. (1 mark)
33+60=0.55cm3/s
54
What are the enzymes used in the digestive system produced by? (1 mark)
specialised cell in glands in the gut and lining
55
Where is amylase produced? (1 mark)
Salivary glands
56
Where is bile produced? (1 mark)
The liver
57
Where is bile stored? (1 mark)
Gall bladder before it is released into the small intestine
58
The large intestine is where what is absorbed from what? (2 marks)
excess water, food
59
Where are faeces stored? (1 mark)
The rectum
60
What are the two types of sugar? (2 marks)
non-reducing and reducing
61
In the benedicts test for sugars, what colours will the solution in the test tube turn to? (3 marks)
Green, yellow or red
62
What is the name of the test that detects starch? (1 mark)
Iodine solution
63
What colour should the iodine test for starch's solution turn to - and what colour should it be normally? (3 marks)
It should turn black or blue-black, and it should change from browny-orange
64
What is the test for proteins called? (1 mark)
Biuret test
65
What colour will the solution in the biuret test for proteins turn to and from if the test tube has protein? (3 marks)
It should turn to pink or purple, and turn from blue
66
What does the Sudan III test test for? (1 mark)
Lipids
67
If the sample in the Sudan III Test for lipids contain liquids, what will happen? (2 marks)
The mixture will separate into two different lays. The top layer will be red if liqids are inside
68
Name the chemical that you would use to test a sample for the presence of starch (1 mark)
Iodine solution
69
Where are the lungs in your body? (1 mark)
In the thorax (the top half of your body)
70
What separates the lungs from the lower part of your body? (1 mark)
The diaphram
71
What protects and what surrounds the lungs? (1 mark)
the ribcage surrounds the lungs, and the pleural membranes surround them.
72
What happens when you breathe in? (5 marks)
The air is breathed in through the trachea, which splits into two tubes named bronchi (bronchus singular) which each go to a different lung. The bronchi then splits into even smaller tubes named bronchioles. They then stop at the alveoli where gas exchange occurs.
73
How does the alveoli carry out gas exchange?
The deoxygenated blood is carried through the capillary where it is oxygenated via diffusion. The oxygen passes through the alveolus to diffuse into the blood cells.
74
If Bob takes 91 breaths in 7 minutes, how many breaths does he take on average per minute? (2 marks)
Number of breaths/number of minutes
91/7=13
75
The circulatory system is a collection of how many circuits of vessels added together? (1 mark)
2 circuits.
76
The heart is a pumping ____ that keeps the blood flowing around the body. The walls of the heart are mostly made of _____ \_\_\_\_\_. The heart has _____ to make sure that blood flows in the right _____ - they prevent it flowing _____ (5 marks)
1) organ, 2) muscle, 3) tissue, 4) direction, 5) backwards
77
Describe the path that blood flows through in the heart (5 marks)
Blood flows into the two atria from the vena cava and the pulmonary vein. The atria contract, pushing the blood into the ventricles. The ventricles contract, forcing the blood into the pulmonary vein and out of the heart. The blood then flows to the organs arteries and returns through the veins. The atria fill again and the whole cycle starts over.
78
True or false: the heart needs its own supply of oxygenated blood. (1 mark)
True.
79
Your resting heart rate is controlled by a group of ____ in the right ____ wall that acts as a \_\_\_\_.
1) cells, 2) atrium, 3) pacemaker
80
What do cells do that cause the heart muscles to contract? (1 mark)
Send small electric impulses that spread around the muscle cells.
81
Why are artificial pacemakers used and for what purpose? (2 marks)
They are used to control heartbeat if the natural one doesn't work.
82
What is an artificial pacemaker? (2 marks)
A small device implanted under the skin and has a wire going to the heart.
83
What do arteries do? (1 mark)
Carry blood away from the heart
84
What do capillaries do? (1 mark)
Exchange the materials at tissues
85
What do veins do? (1 mark)
carry blood to the heart
86
Why are the artery walls strong and elastic? (1 mark)
To cope with the high pressure the blood is pumped out of the heart in
87
What is the name of the hole down the middle of the artery? (1 mark)
the lumen
88
What do arteries branch into?
Capillaries
89
Why do capilleries have permeable walls? (1 mark)
So substances can diffuse in and out
90
What do capillaries supply and what do they take away? (3 marks)
They supply food and oxygen, they take away waste like CO2
91
What join up to become veins? (1 mark)
Capillaries
92
Why do veins have thin walls? (1 mark)
Because the blood being pumped to the heart is at a lower pressure
93
Why do veins have bigger lumens than arteries? (1 mark)
To help the blood flow
94
What's the purpose of the valves in veins? (1 mark)
To prevent backflow of blood
95
What is the formula for rate of blood flow? (2 marks)
rate of blood flow = volume of blood/number of minutes
96
The formula for rate of blood flow is is rate of blood flow = volume of blood/number of minutes. Calculate the rate of blood flow through the arteries if 1464ml of blood passes through an artery in 4.5 minutes.
rate of blood flow = volume of blood/number of minutes
1465/4.5=325ml/min
97
What is the job of the red blood cells? (1 mark)
To carry oxygen from the lungs to all cells around the body
98
What is the shape of a red blood cell? (1 mark)
a biconcave disc
99
What do red blood cells have to allow more oxygen to be absorbed? (2 marks)
Large surface area, no nucleas
100
What is the name of the red pigmet that is contained inside a red blood cells and what does it do? (3 marks)
haemoglobin, which binds to oxygen to becomes oxyhaemoglobin
101
How does oxygenget to the body tissues from the red blood cells? (2 marks)
the oxyhaemoglobin splits up into the haemglobin and the oxygen so that the blood cell can release the oxygen into the cells.
102
What is the job of the white blood cell? (1 mark)
To defend against infection
103
White blood cells can change shape to gobble up unwelcome microorganisms. What is the name of the process? (1 mark)
phagocytosis
104
True or false: white blood cells can produce antibodies to fight against microorganisms (1 mark)
true
105
What do white blood cells have that red blood cells don't? (1 mark)
A nucleus
106
What is the job of a platelet? (1 mark)
To help blood clot
107
Name the fragment
These are small fragments of cells (1 mark)
platelet
108
Do platelets have nucleui? (1 mark)
No
109
Why are platelets needed for clotting vessels? (2 marks)
To stop blood pouring out and to stop microorganisms getting in.
110
The lack of what can cause excessive bleeding and bruising? (1 mark)
Platelets
111
What is the name of the pale liquid which carries everything to do with blood? (1 mark)
plasma
112
Nutrients like _____ and _____ acids are carried by \_\_\_\_\_.
1) glucose, 2) amino, 3) plasma
113
Name everything that plasma carries. (7 marks)
Red and white blood cells and platelets
Nutrients like glucose and amino acids
Carbon dioxide (from the organs to the lungs)
Urea (from the liver to the kidneys)
Hormones
Proteins
Antibodies and antitoxins produced by the white blood cells
114
What must happen to cause coronary heart disease? (3 marks)
the coronary arteries that supply blood to the muscle of the heart get blocked by layers of fatty material building up, which causes a lack of oxygen to the heart muscle as the ateries become narrow. This results in a heart attack.
115
What are stents? (2 marks)
tubes that are inserted into arteries. They lower the risk of a heart attack in people with coronary heart disease
116
What are the purpose of stents? (2 marks)
To keep the heart beating by keeping arteries open so that blood can pass through the heart to the muscles.
117
Name two advantages of stents (2 marks)
They are effective for a long time, the recovery time from the surgery is quick
118
Name three downsides to stents (3 marks)
There is a risk of complications during the operation, such as a heart attack. There is a risk of infection from the surgery. There is a risk of patients developing a blood clot near the stent - this is called thrombosis
119
What are statins? (1 mark)
Drugs that reduce the cholesterol in the blood
120
Why is too much cholesterol known for leading to health problems? (2 marks)
It can cause fatty deposits in the bloodstream in the arteries, which can lead to heart disease
121
Name three advantages of statins (3 marks)
By reducing the amount of cholesterol in the blood, they can reduce the risk of coronary heart disease and heart attacks
Statins can also increase the amount of beneficial type of cholesterol in your bloodstream
Some studies suggest that statins may also help prevent some other diseases.
122
Name three disadvantages of statins (3 marks)
Statins are a long-term drug that must be taken regularly. Forgetting can lead to many different health problems.
Statins can sometimes cause negative side effects, such as kidney failure, liver damage and memory loss.
The effect of statins isn't instant. It takes time to kick in.
123
Why might a doctor fit an artifical heart after a patient gains heart failure? (2 marks)
If a heart transplant is needed and a heart donor is not available or aren't the best option.
124
What is an artificial heart? (2 marks)
A mechanical device that pumps blood if someone's heart has failed. They are usually only temporary until a heart donor is found
125
What can surgery to fit an artificial heart lead to? (2 marks)
Internal bleeding and infection.
126
Explain why artificial hearts are less likely to be rejected by the body's immune system than a donor heart. (2 marks)
Because they're made from metals and plastics, so the body doesn't recognise them as 'foreign' and as of such doesn't attack them the same way as it does with living tissue.
127
Artificial hearts doesn't work as well as healthy natural ones. Explain. (3 marks)
Parts of the eletrical motor could fail, and blood doesn't flow through the artificial hearts as smoothly as the others, which could cause blood clots and lead to strokes.
128
Why does a man with a artificial heart have to take drugs? (2 marks)
To thin their blood and make sure they don't get blood clolts and strokes.
129
Name the two types of replacement heart valves (2 marks)
Biological and mechanical
130
What can cause heart valves to need to be replaced? (3 marks)
Heart attacks, infection and old age can damage/weaken heart valves
131
Why is heart valve tissue stiffening bad? What does it prevent? (3 marks)
The valves opening properly, and it may cause the valves to become leaky, allowing blood to flow in both directions rather than just forwards. This would mean that the blood wouldn't circulate properly and could be very damaging
132
How can severe heart valve damage be treated? (1 mark)
By replacing the valve with a valve from either a human or a valve from another mammal
133
If a biological valve is not available, what could a doctor do to replace the faulty valve? (1 mark)
place a mechanical valve inside instead
134
When someone loses a lot of blood, what can a doctor do to save the life? (1 mark)
Use artificial blood as the heart can still pump the blood
135
What is artificial blood? (1 mark)
A blood substitute used to replace the lost volume of blood
136
What is the difference between a communicable disease and a non-communicable disease? (2 marks)
A communicable disease is one that can be transferred from person to person or between animals and humans. They can be caused by animals and people alike.
A non-communicable disease is one that cannot be spread from person to person. They last for much longer and are usually much worse.
137
Give three examples of non-communicable diseases (3 marks)
Asthma, cancer and coronar heart disease
138
Name two communicable diseases (2 marks)
Measles and malaria
139
Communicable or non-communicable (1 mark)
People who have problems with their immune system have an increased chance of having problems with communicable/non-communicable diseases
Communicable
140
Communicable or non-communicable (1 mark)
Cancer is a communicable/non-communicable disease.
141
What is cancer? (1 mark)
A non-communicable disease that is caused by the overgrowing of cells in a particular area of the body
142
Name three factors that can affect your heath (3 marks)
Your diet, is it balanced or not. A balanced diet should provide your body with everything it needs in the right quanities
The stress you are under - being under constant stress can lead to health issues
If you have easy access to medicines, food, clean water etc
143
What is meant by health? (1 mark)
The state of physical and mental wellbeing
144
145
What are risk factors? (1 mark)
The things linked to an increase in the likelihood that a person will develop a certain disease during their lifetime.
146
Name an example of a risk factor (1 mark)
How much exercise one does
147
what are risk factors known to cause? (1 mark)
Non-communicable diseases are caused by several different risk factors interacting with each other.
148
Why are non-communicable diseases such as Type 2 diabetes more likely in developed countries than in others? (3 marks)
Because people are more likely to have higher incomes in developed countries and have a higher intake of fatty foods. They are also more likely to smoke and have poor diet and exercise.
149
Which risk factors are known to cause diseases? (4 marks)
Smoking can cause cardiovascular disease, lung disease and lung cancer as the tar and nicotine is bad for the lungs. Smoking when pregnant causes a lot of health deffects for the unborn child.
Obesity is thought to cause Type 2 diabetes by making the body less sensitive or more resistant to insulin.
Drinking too much alcohol has been shown to cause liver disease.
Cancer can be caused by explicit exposure to ionising radiation and certain substances.
150
How can non-communicable diseases be costly in financial terms? (2 marks)
Researching diseases is very costly (use NHS as example). Health organisations suffer that a lot.
Families may have to move or adapt their homes to help a family member with a disease.
151
What causes cancer? (1 mark)
Uncontrolled cell growth and division.
152
Are tumours cancerous? (1 mark)
Not necessarily.
153
What are the two types of tumours? (2 marks)
Benign and malignant.
Benign is where the tumour grows until there is no more rooms, and it stays in one part of the body and doesn't spread.
Malignant is when the tumour spreads to other parts of the body - which is the essence of how cancer works. They travel through the bloodstream to do this.
154
Name four risk factors that can cause cancer. (4 marks)
Smoking - lung cancer
Obesit - bowel, liver and kindey cancer
UV exposure - skin cancer
Viral infection - liver cancer (via STDs)
155
How can risk factors and genetics be associated? (1 marks)
You can inherit faulty genes that make you more susceptible to cancer.
156
Name three plant organs (3 marks)
Stems, roots, leaves
157
Explain five plant tissues (5 marks)
Epidermal tissue - this covers the whole plant
Palisade mesophyll tissue - this is the art of the leaf where most photosynthesis happens
Spongy mesophyll tissue - this is also in the leaf, and contains big air spaces to allow gases to diffuse in and out
Xylem and phloem - they transspot things like wwater, mineral ions and food
Meristem tissue - this is found at the growing tips of shoots and roots and is able to differentiate into lots of different types of plant cells, allowing the plant to grow.
158
What are epidermal tissues covered in? (1 mark)
Waxy cuticle, which helps to reduce water loss by evaporation.
159
Palisade layer has lots of \_\_\_\_\_
Chloroplasts
160
\_\_\_\_\_ and _____ form a network of _____ bundles, which deliver water and other nutrients to the entire ____ and take away the glucose produced by \_\_\_\_\_
1) xylem, 2) phloem, 3) vascular, 4) leaf, 5) photosynthesis
161
What is the difference between a phloem tube and a xylem tube? (2 mark)
Phloem tubes transport food, whereas exlym tubes take up water.
Phloem is made of living tissues and it can go in both directions, but xylem tubes are made of dead cells joined together with no walls.
162
What causes transpiration? (3 mark)
Evaporation and diffusion of water on the plant's surface. The evaporation causes a slight shortage of water in the leaf and so more water is drawn up from the rest of the plant through the xylem vessels to replace it. This in turns means more water is drawn up from the roots, and so there's a constant transpiration stream of water through the plant.
163
Name the four things transpiration is affected by (4 marks)
Light intensity - the brighter the light, the greater the transpiration rate. Stomata close the darker it gets.
temperature - the warmer it is, the faster transpiration
Air flow - the better the air flow around a leaf, the greater the transpiration rate
Humidity - the drier the air around a leaf, the faster transpiration happens. If the air is humid, there is a lot of water in it already, so there's not much difference between the inside and outside of the leaf
164
You can estimate the rate by transpiration. How? (2 marks)
By measuring the uptake of water by a plant because you can assume that water uptake is directly related to the water loss by the leaves
165
Describe a guard cell (5 marks)
They have a kidney shape which opens and closes the stomata. Thin outer walls and thickened inner walls make the opening and closing work, they're also very sensitive to light and close at night.
They are found on the underside of a leaf.
They suck up the water and become plump and turgid so the stomata opens and gases can be exchanged photosynthesis. Guard cells are therefore adapted for gas exchange and controlling water loss.
