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A Level Biology > Topic 1 > Flashcards

Topic 1 Flashcards

(110 cards)

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1
Q

In small organisms how are substances moved around the body

A

Via diffusion as they travel short distances

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2
Q

Why do multicellular organisms need a mass transport system and don’t rely on diffusion

A

As diffusion is to slow in moving substances around the body

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3
Q

What are the two types of circulatory system

A

Open and closed circulatory system

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4
Q

What type of organisms rely on open circulatory system

A

Small organisms like insects

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5
Q

Explain how open circulatory systems work

A

A simple heart pumps blood into open cavities around the animals and substances diffuse between the blood and cell

When heart muscle relaxes blood is drawn from open cavities via small cables openings

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6
Q

What is a closed circulatory system

A

When blood is enclosed in blood vessels and travels under high pressure and faster

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7
Q

In a closed circulatory how does blood flow

A

From the heart blood will flow under high pressure along arteries and after arterioles then into capillaries ( come in contact with cells)

Substances are exchanged between the blood in capillaries and body cells

After passing through capillaries blood will return to the heart via venules then veins

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8
Q

Why do veins contains valves

A

In order to prevent the back flow of blood

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9
Q

What types of animals have closed circulatory system

A

They are larger size and more active

Ie pigs humans

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10
Q

What are the two types of closed circulatory system

A

Single and double circulatory system

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11
Q

What the difference between single and double circulatory system

A

In double blood returns to the heart twice before being pumped to the rest of the body

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12
Q

With reference to a fish how does single circulatory systems work

A

Deoxygenated blood is pumped from the heart to the gills

Gaseous exchange occurs in the gills in which co2 in the blood will diffuse into the surrounding water and oxygen from water will enter into the blood

The blood will flow from the gills to the rest of the body then finally arrive at the heart

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13
Q

Describe how a double circulatory system works

A

The right ventricle in the heart pumps deoxygenated blood into the lungs so it revives oxygen

The oxygenated blood returns to the heart where it is pumped again via the left ventricle to the rest of the body

The blood retuning to the heart is given a boost so it allows the blood to circulate around the body quicker

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14
Q

What does the boost given to the blood give animals

A

It gives mammals are higher metabolism due to oxygen and food needed for metabolism process is delivered quickly to cells

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15
Q

What is a mass flows

A

When a liquid and its contents travel in one direction due to change the in pressure

Ie blood

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16
Q

What is the transport medium in mass flow

A

Blood which contains plasma(which is made up of largely water

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17
Q

What substances does plasma carry

A 
Oxygen 
Co2
Urea
Cells red white 
Glucose
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18
Q

What is meant by water being a polar(dipole molecules

A

That it has an unevenly

Distributed electrical charge

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19
Q

What are the two properties of water

A

Solvent and thermal properties

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20
Q

What is meant by water having solvent properties and is it beneficial

A

Due to its polar nature it means that substances ie ionic ones can dissolve in it meaning it can be transported around the body easily

Chemical react with water by hydrolysis and condensation reactions

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21
Q

What is meant by water having high thermal properties

A

The specific heat capacity is high due to having lots of hydrogen bonds that are hard to break so has high boiling point

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22
Q

What are the benefits of water high specific heat capacity for organisms

A

Helps animals avoid rapid changes in internal temperature

Allows them to maintain a constant temperature in varied weather

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23
Q

What is the role of the right side of the heart and the left side

A

The right side receives deoxygenated blood which it pumps to the lungs

The left side receives oxygenated blood and pumps it to the rest of the body

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24
Q

What is the role of the aorta,coronary arteries,superior vena cava,valves

A

Aorta-the biggest artery which transports blood to the rest of the body

Coronary artery-supplies oxygen to the rest of the body

Valves-prevent the backflow of blood

Superior vena cava-supplies blood from the head and arms

Inferior vena cava-supplies blood from the rest of the body

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25
What are the 3 main blood vessels
Arteries Capillaries Veins
26
What 3 things to both arteries and veins contain and state the functions of these things
Elastic fibres-they allow the blood vessels to stretch and recoil Collagen which enables them to be strong and durable Smooth muscle cells- they allow the blood vessels to constrict and dialate
27
Give characteristics of arteries
They carry blood at high pressure. They have a narrow lumen They thicker muscle layer and elastic tissue and more collagen They contain endothelium inside the lumen
28
Give some characteristics of veins
Thinner walls Wider lumen Valves Less collagen and smooth muscle and fewer elastic fibres
29
How does blood move through blood vessels
When systole takes place it forces the elastic walls of the artery to stretch as blood is forced out when diastole takes place the artery recoils and this pushes the blood foward And blood moves along the arteries in series of stretches and recoils as a result of diastole
30
What happens when blood reaches the capillary and what feature of the capillaries allow for this to happen
Exchange of substances takes place in the capillaries via diffusion, the capillaries have a narrow lumen which creates friction which slows blood flow down enabling this to happen
31
How does blood in the veins back to the heart
As we breath in low pressure is created In the throw and this helps in drawing back blood into the heat via veins
32
What is the cardiac cycle f
One complete sequence of the heat pumping and filing up with blood
33
What's heart rate
The number of times the heart beats per minute
34
What is systole and diastole
Systole when the heart contracts Diastole- when the heart relaxes
35
What are the 3 stages in the cardiac cycle
Atrial systole Ventricular systole Cardiac diastole
36
What occurs in atrial systole and state which out of atrial valves and semi lunar valves which one is open
Blood returns to the atrium via the Vena cava and pulmonary vein the pressure increases in the atria causing it to contract and forcing blood through into the ventricles which forces the atrioventricular valves open Sl valves closed
37
What is ventricular systole and which valves are open
The ventricles contract which increases pressure forcing the av valves to close but the semi lunar valves open as the blood is pushed up through the aorta and pv vein
38
What is cardiac diastole
When blood returns to the heart with the atria starting to fill again due to high pressure in the pulmonary vain and vena cava Semi lunar valves close due to high blood pressure in the aorta and pulmonary artery this prevents back flow of blood
39
What is atherosclerosis
The hardening of arteries which results in raised blood pressure
40
Describe the stages atherosclerosis
The endothelium layer in the blood vessel is damaged due to hbp or toxins Results in an inflammatory response in which leads to an atheroma building up their At the site calcium salts and fibrous tissue builds up and this results in a plaque on the inner walls of the artery leads to the artery hardening The lumen of artery becomes narrow as a result of the plaque and this causes high blood pressure so positive feedback builds up this means plaques form in the body
41
What do blood clots do
They seal breaks in a blood vessel which helps in limiting blood loss and helps in preventing pathogens entering open wounds
42
How does a temporary platelet plug form
Platelets change to spheres with long thin projections this allows it to stick to expose collagen in the artery wall and to each other which forms the plug
43
Describe the stages In the clotting cascade
A protein called thromboplastin is released from by damaged tissue and platelets Thromboplastin helps catalyse conversion of prothrombin a protein into a enzyme called thrombin calcium and potassium ions need to be present for this to occur Thrombin helps catalyse the conversion of fibrinogen into a insoluble protein called fibrin A mesh of fibrin forms and traps the platelets and red blood cells forming a clot
44
What is a risk
The probability of an unwanted event or outcome occuring
45
Give reasons as to why risks are overestimated
``` Not natural Unfair Dreaded Very small Involuntary ```
46
What is a correlation
When a change in one variable is accompanied by a change in another variable
47
What is a postive correlation
An increase in one variable is accompanied with an increase in another variable
48
What is a negative variable
A decrease in one variable results in an increase in another variable
49
What is meant be casually linked,causation
When a change in one variable is responsible for a change in another variable
50
What test is used to identify if two variables are correlated
Spearmans rank i
51
Give two methods used in investigating CVD
Cohort studies Case control studies
52
What is a cohort
Following large groups of people around of a period of time to see if they develop the disease or not Any risk factors that they have been exposed to are recorded
53
What are issues with cohert studies
They are expensive They take a long period of time
54
What is a case control study
When a group of people with a certain disease are compared with a control group information about risk factors they have been exposed to are collected
55
Name risk factors of CVD
``` obesity High blood pressure Smoking inactivity Inheritance Blood cholesterol ```
56
What is blood pressure
It's a measure of the hydrostatic force of blood against the walls of a blood vessel
57
What are the two types of blood pressure
Systolic blood pressure-when the ventricles contract and force blood in the artery this is when BP is at its highest Diastolic-blood pressure is when the ventricles relax and bp is at its lowest
58
What is peripheral resistance
When friction occurs when the blood and walls of blood vessels come in contact
59
What is Oedema
When swelling occurs as a result of tissue fluid build up
60
What is oedema a sign of and how
High blood pressure as to much tissue fluid is being forced out of blood plasma which results in fluid accumulating
61
What are monosaccharides
Single sugar units
62
How do diasaccrides and polysaccharides form
As a result of condensation reactions between sugar units
63
What are the 3 monosaccharides
Fructose Glucose Galactose
64
How can do distinguish between the 3 monosaccharides
The OH are different Galactose OH are high Fructose are high and low Glucose both low
65
What is the bond called when monosaccharides react to form disaccharides
Glycosidic bond that's named after the carbons where the bonds occur
66
What is the reaction between sugar units called and what's released
It's condensation reactions and water is releases
67
What are the 3 most common disaccharides and how are they made
Lactose-from glucose and galactose in milk Sucrose-glucose and fructose sugar in plants Maltose-two glucose
68
What is hydrolysis
When water is added to a glycosidic bond causing it to split up
69
Give the 3 types of polysaccharide
Starch Glycogen Cellulose
70
Why are glycogen and starch suitable for storage
They are compact with low solubility in water Osmosis isn't affected by it so ester can be moved in and out freely
71
What is starch and glycogen made up of
Amylose and amylopectin
72
Describe the structure of amylose and how it's beneficial for starch
It made of alpha glucose and contains 1,4 glycosidic bond that coil in a spiral which aids in making starch and glycogen compact and suitable for storage
73
Describe the structure of amylopectin and how it's beneficial for starch and glycogen as
It's has 1,6 glycosidic bonds and 1,4 that has lots of side chains which means it can be broken down easily and glucose can be released it's made of alpha glucose
74
What are Lipids
Fats and oils and are triglycerides
75
What are triglycerides made up of
3 fatty acids and glycerol
76
How are triglycerides produced and what is the bond that holds them
Then are produced by condesation reaction in which ester bonds form
77
What are saturated fats
They contain the maximum number of hydrogen atoms in a chain
78
Why do saturated fats have high melting and boiling points
As the hydrocarbon chains pack closely together and they have strong intermolecular forces between them
79
What are unsaturated fats
They have double bond in their hydrocarbon chain
80
Why do unsaturated fats have lower melting points
As they have kinks in their chain which mean that they don't pack closely together so the strength of the intermolecular forces are weaker
81
What is chloesterol and give its uses
It's a short lipid molecule It's used in sex hormones In cell membrane for their functioning and organisation
82
Give the two types of lipoprotein
Low density lipoprotein | High density lipoprotein
83
How does cholesterol move in our blood steam
It combines with proteins to form lipoprotein
84
How are low density lipoprotein formed
When triglycerides and cholesterol protein combine
85
What is the function of low density lipoprotein and describe what happens after
It carries cholesterol to our cells Where the cholesterol is taken up by cell membrane receptors in our cells and it's involved in maintained of the cell membrane
86
What is the problem with LDL
When their to much blood cholesterol it leads to an excess overload on the csm receptor leads to atheroma developing
87
How is HDl formed and what's the difference with LDL
When triglycerides in our diet combine with protein and cholesterol It has a high level of protein
88
What is the role of HDl
It's used in to transport cholesterol to the liver to be broken down
89
Give two gene disorders that contribute to CVD
FH Apolipoprotein
90
What is FH mutation and how does it link to CVD
These are mutations of the ldlr gene which cause LDL receptors shape not to form properly making it less efficient in taking cholesterol up
91
What does Apolipoprotein do
They stabilise lipoprotein structure and they recognise receptors that are involved in lipoprotein uptake
92
What is the role anti hypentenvies and give examples
They help in reducing blood pressure Dietetics- reduce amount of salt that is reabsorbed by blood which reduces blood volume Beta blockers- reduce strength of heart beat Vadodilators-widen blood vessels
93
What risks are their with taking anti hypertensives
``` Fainting Allergic reaction Depression Headaches Palpitations Abnormal heart rhythms ```
94
What do stains do
They reduce blood cholesterol
95
Give some side effects of using statins
nosebleeds Nausea Muscle joint pain Headaches
96
What do anticoagulants do
They reduce formation of blood clots
97
What are side effects of anticoagulants
``` Allegic reactions Fainting Swelling of tissue Excessive bleeding Osteoporosis ```
98
What is the role of the platelet inhibiting drugs
They prevent platelets clumping together to form blood clots
99
What's a problem with platelet inhibiting drugs
``` Nausea Rashes Liver function Problems Diarrhoea ```
100
What do Ace inhibitors do
They prevent the synthesis of angiotensin II which causes vasoconstriction of blood vessels so help in lowering blood pressure
101
What are issues with Ace inhibitors
Dry cough Rapid lowering in blood pressure Abnormal heart rhythms Kidney function reduces
102
What do calcium channel blockers do
They block calcium channels in lining of arteries meaning they can't interact so blood vessels don't contract lowers blood pressure
103
What side effects are their of taking diuretics
Headaches Dizziness Swollen ankles Abnormal heart rhythms
104
State role of mrna and tRNA in protein synthesis
Mrna- it's a copy of the template strand Binds to the ribosome it's used in translation tRNA-it attaches to a specfic amino acid Two mrna bring amino acids together
105
Distinguish between amylose and amylopectin
Amylose is straight chained and unbraced contains 1,4 glycosidic bond and its spiral Amylopectin is branched Contains 1,4 and 1,6 glycosidic bond Has side chains
106
What feature of water gives its thermal and solvent properties
Hydrogen bonds
107
Why is chloesterol insouble in water
It contains fatty acid tails in that are hydrophobic
108
State how a diet that contains lots of saturated fats can result in CVD
They contain lots LDL cholesterol Which leads to atherma forming this in itself can lead to high blood pressure
109
In ventricular systole what causes the atriaventricular valves to close
The increased pressure in the ventricles
110
In cardiac dyostle what causes the semi lunar valves to close
The high pressure in the aorta and pulmonary artery

A Level Biology (9 decks)

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