AS COMP 2 Flashcards
(80 cards)
1
Q
what are the 4 features for gas exchange?
A
- large surface area
- thin walls for short diffusion path
- steep concentration gradient
- permeable
2
Q
What happens when carbon dioxide can’t be removed fast enough?
A
Build up a high concentration causing cytoplasm to become acidic for enzymes to function
3
Q
What are earthworms 4 characteristics
A
- skin is respiratory surface
- haemoglobin in blood, low metabolic rate
- cylindrical so sa:vol is smaller
- co2 diffuses out down concentration gradient
4
Q
3 Characteristics of amphibians
A
- skin is moist and permeable
- well developed capillary network
- gas exchange in skin and lungs
5
Q
Characteristic of reptile
A
Lung has a complex internal structure, increase surface area
6
Q
Characteristic of bird
A
Large volume of oxygen for flight as requires more energy
7
Q
6 characteristics of bony fish
A
High surface area of filimants
Short diffusion path
Countercurrent flow - steel gradient
Rich blood supply
Ventilation system
One way flow
8
Q
Process of uptake of water by ventilation
A
Mouth opens
Operculum closes
Floor of mouth lowers
Volume inside mouth increases and pressure decreases
Water flows in as external pressure is higher than inside mouth
9
Q
Process of removal of water using ventilation
A
Mouth closes
Operculum opens
Floor of mouth rises
Volume inside mouth decreases and pressure increases
Water flows out as pressure is higher inside
10
Q
What is countercurrent flow?
A
Blood moves in one direction and water moves opposite
11
Q
What happens if we increase distance of lamella ?
A
Concentration of oxygen increases and water decreases
12
Q
Define negative pressure
A
Pressure inside lungs must be below atmospheric pressure for air to come in
13
Q
Process of inspiration/inhalation
A
- external intercostal muscles contract
- ribs pulled upwards and outwards
- same time diaphragm contracts and flattens
- outer pleural membrane is pulled up and out with ribs and lower part is pulled with diaphragm, inner membrane follows and lung expands increasing volume inside alveoli
- reduces pressure in lungs
- atmospheric pressure is greater than pressure in lungs so air is forced out
14
Q
Process if expiration/exhalation
A
- external intercostal muscles relax
- ribs are pulled downwards and inwards
- diaphragm muscles relax and domes upwards
- pleural membrane moves down and in with ribs and lower parts move up with diaphragm, volume inside lung decrease decreasing volume in alveoli
- air pressure greater than atmospheric, air forced out
15
Q
What is surfactant in alveoli made of and its use
A
Made of secretions containing phospholipids and proteins
Used for preventing collapse in exhalation as it has low surface tension
16
Q
4 Characteristics of gas exchange in alveolus
A
Large surface area
Gasses dissolve in surfactant moisture lining
Walls made of squamous epithelium, one cell thick for short diffusion path
Extensive capillary network to maintain diffusion gradient
17
Q
Stages of gas exchange in alveolus
A
- deoxygenated blood enters the capillary surrounding the alveoli
- oxygen diffuses out of the air in the alveoli into red blood cells in capillary
- carbon dioxide diffuse out of the plasma in the capillary into the air in the alveoli from where it is exhaled
18
Q
What happens to guard cells during the day?
A
Open and become turgid and swell
19
Q
What happens to guard cells during the night
A
Close and become flaccid
20
Q
Define open circulatory system
A
Blood does not move around the body in blood vessels
21
Q
Define closed circulatory system
A
Blood does move in blood vessels
22
Q
What are 2 types of close system
A
Single circulation
Double circulation
23
Q
What is single circulation
A
Blood moves through the heart once in its passage around the body
24
Q
Define double circulation
A
Blood passes through heart twice in its passage around the body
25
What does pulmonary circulation do ?
Serves the lungs
Right side of the heart pumps deoxygenated blood to the lungs and oxygenated blood returns from the lungs to the left side of the heart
26
What is systemic circulation ?
Serves body tissue
The left side of the heart pumps the oxygenated blood to the tissues and deoxygenated blood from the body returns to the right side of the heart
27
How many layers does the structure of artery and veins have?
3 layered structure
28
Description of tunica intima
Innermost layer
Single layer of endothelium
Supported by Elastic rich collagen
Smooth lining to reduce friction
29
Description of tunica media
Middle layer
Contains elastic fibres and smooth muscle
Thicker in arteries than veins
30
Description of tunica externa
Outer layer
Contains collagen fibres which resist overstretching
31
Description of arteries
Carries blood away from heart
Thick muscular walls to withstand high pressure
Branches into smaller vessels called arterioles
32
Description of veins
Larger lumen
Thinner walls
Carry blood into heart
Have semi lunar valves
33
Description of capillaries
Thin walls
Permiable to water and solutes to exchange material between blood and tissues
34
Define myogenic contraction
Can contract and relax rhythmically
35
Define systole
Heart contract
36
Define diastole
Heath relaxes
37
What are the 3 stages of cardiac cycle?
Article systole
Ventricular systole
Diastole
38
Process of Arita systole
Atriums walls contact causing blood pressure to increase in atria
Thus pushes blood through tricuspid and bicuspid valves down into ventricles which are relaxed
39
Process of ventricular systole
Ventricles contract causing blood pressure in ventricles to increase
This forces blood up through the semi lunar valves out of the heart and until pulmonary artery and aorta
Pulmonary artery carries deoxygenated blood to lungs and aorta carries oxygenated blood to rest of body
40
Process of diastole
Ventricles relax causing volume to increase and pressure to fall
Risk of back flow in ventricles from pulmonary artery and aorta
Semi lunar valves shut
Atria relaxes so blood moves from vena cavae and pulmonary veins enter atria
Cycle starts again
41
Define SAN node
An area of the heart muscle in the right atrium that initiates a wave of electrical excitation across the atria to generate contraction of the heart muscle
Known as a pacemaker
42
Description of red blood cells
Biconcave disk for larger surface area
thin middle for short diffusion distance
No nucleus for more haemoglobin
43
Define affinity
Degree to which two molecules are attracted to each other
44
Define cooperative binding
Increasing ease with which haemoglobin binds its second and third oxygen molecules as the structure of haemoglobin changes
45
What is Bohr effect
Movement of oxygen dissociation curve to the right at the higher partial pressure of carbon dioxide because at a given oxygen partial pressure haemoglobin has lower affinity for oxygen 
46
Steps on how carbon dioxide is transported in the blood
1. Carbon dioxide diffuses out of red blood cells
2. Carbonic anhydrase catalyses carbonic acid
3. This dissociates H+ and HCO3- ions
4. HCO3- ions diffuse out of red blood cells into plasma
5. to maintain balance of charges chloride ions diffuse into red blood cells from plasma this is called chloride shift
6. H+ ions combine with haemoglobin creating haemoglominic acid, this removes hydrogen ions so the pH of red blood cells doesn’t fall
7. Oxygen diffuses out of red blood cells into tissue
47
Describe arterial end of capillary
High hydrostatic pressure pushes liquid outwards from capillary to spaces between surrounding cells
Hydrostatic pressure is greater than plasma solute potential so water and solutes are forced out through capillary walls into spaces between cells
48
Describe venuous end of capillary
Hydrostatic pressure is Lower at arterial end because volume is reduced by fluid loss
Plasma proteins are more concentrated in blood as water has been lost
Osmotic pressure is greater as water passes back into capillaries by osmosis
49
Name 3 pathways and process
Apoplast - cell walls
Symplast - cytoplasm to plasmodesmata
Vascular - vacuole to vacuole
50
Two functions of xylem
Transport water and dissolved minerals - vessels
Strength and support - fibres
51
4 factors effecting transpiration
Temperature
Humidity
Light intensity
Wind intensity
52
How does temperature affect transpiration?
High temperatures cause more transpiration as particle have higher kinetic energy and a faster rate of water molecules evaporate from mesophyll and diffuse faster
53
How does humidity affect transpiration?
High humidity causes less transpiration
Waste is lost as there is high saturation of water in the air
54
How does wind movement effect transpiration?
High movement, more transpiration as good airflow removes water vapour from air casing a concentration gradient between air and leaf : increasing water loss
55
How does light intensity affect transpiration?
High light intensity causes more transpiration as guard cells are more responsive
They are turgid and stomata opens allowing more water to be lost
56
How does sucrose enter phloem - translocation?
By active loading where companion cells use ATP to transport H+ ions into surrounding tissue.
H+ ions diffuse back into co-transporters which bring sucrose into companion cells through plasmodesmata
57
What happens at source ?
Decrease in water potential as water moves into sieve tubes by active transport increasing hydrostatic pressure in sieve tubes at source
58
What happens at sink?
Sucrose used in cells at sink cause increase in concentration of sucrose and diffuse at sieve tubes, raises waste potential so water moves out by osmosis lowering hydrostatic pressure so solution flows from source to sink from high to low pressure
59
Description of hydrophytes
Poor developed xylem so little need for water transport
Stems and leaves have large air spaces for co2 and o2 reservoir for buoyancy
No cuticles
Stomata on upper surface
60
Description of mesophytes
Shed leaves before winter to not lose water when scarce
Aerial parts die off at winter to not be exposed to cold and frost
61
Description of xerophytes
Low water
Rolled leaves to reduce transpiration
Sunken stomata to trap humid air causing decrease water potential so less diffusion
Interlocking hair to trap water vapour decreasing concentration gradient
Waterproof cuticle to prevent water loss
62
Define autotrophic
Organisms make their own organic material from inorganic raw materials carbon dioxide and water
63
Define photoautotrohic
Use light as the energy source and perform photosynthesis
64
Define photoautotrohic
Use light as the energy source and perform photosynthesis
65
Define chemautotrophic
Use energy from chemical reaction
66
Define heterotrophic
Organisms cannot make their own organic material and consume other organisms
67
Define saprotroph
Organism that derives energy and raw material for growth from dead or decaying material
68
Define holozoic nutrition
Organisms that ingest food digest it and egest the indigestible remains
69
What does stomach digest?
Proteins
70
What does duodenum digest?
Carbohydrates fats and proteins
71
What does ileum digest and absorb?
Carbohydrates fats and proteins
Absorb digested food and water
72
What does serosa do
Protects the gut wall and reduces friction
73
What does submucosa do?
Contains blood and lymph vessels which remove absorbed products of digestion
74
What does mucosa do?
Lines the gut wall, secrete digestive juices and absorb digested food
75
What are the 3 domains?
Eubacteria
Archaea
Eukaryota
76
What are the 5 kingdoms ?
Prokaryota
Protoctista
Fungi
Plant
Animila
77
What is dna sequencing?
DNA analysis to see how similar species are
78
What is DNA hybridisation?
Comparing DNA base sequences of two species
79
What is amino acid sequences?
Similarly in the amino acid sequence of the same protein in two species to reflect how close they are to
80
Define biodiversity
Number of organisms within each species
