B2.2 - transport and blood Flashcards

1
Q

why are tapeworms able to survive with a single circulatory system?

A
  • has a high surface area to volume ratio

- nutrients can dissolve quick enough to sustain the organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why do multicellular organisms require adapted exchange surfaces?

A
  • because their surface area to volume ratio is low

- so diffusion cannot occur fast enough to meet the organism’s demand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how have the lungs adapted to maximise the rate of diffusion into the bloodstream?

A

lungs contain lots of alveoli (increase surface area)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how have alveoli adapted to maximise diffusion? - 4

A
  • steep concentration gradient (ventilation through air)
  • thin alveoli walls (one cell thick - easy diffusion)
  • high surface area to volume ratio
  • capillaries close to the alveoli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how is the small intestine adapted to maximise diffusion rate?

A

finger like villi on walls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how do villi affect the rate of diffusion in the small intestine?

A

increase surface area

with microscopic villi on villi themselves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

give examples of exchange surfaces and transport systems

A
  • alveoli
  • villi
  • xylem
  • phloem
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the function of the circulatory system?

A

transport substances around the body and the cells that need them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the hollow cavity in the centre of blood vessels called?

A

lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

state features of an artery

A
  • thick outer wall (high pressure from heart)
  • thick layer of muscle + elastic fibres (to contract)
  • small lumen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

state features of a vein (physical features)

A
  • thin outer wall
  • thin layer of muscle + elastic fibres
  • large lumen
  • valves (stop blood flowing wrong way)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

state features of capillaries

A
  • small lumen (allows small diffusion distance)
  • single wall of cells
    (maximise diffusion through semipermeable walls)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the function of arteries?

A

carry blood away from the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the function of veins?

A

return blood to heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why do veins have valves?

A
  • prevent back flow

- since blood is flowing at low pressure, it is more likely to flow backwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

function of capillaries?

A

link arteries and veins in tissues + organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how do arteries work?

A
  • muscle fibres contract to push blood forward

- then relax (and then the lumen expands)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does the double circulatory system mean?
(how does that affect the pressure compared to a single circulatory ststem)
and what does it allow the body to do?

A
  • for each journey around the body, blood is pumped twice
    (so pressure is higher than single circulatory system)
  • materials are transported quickly around body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

why are alveoli moist?

A

gases can only cross cell membrane when dissolved in water/aqueous solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the use of haemoglobin?

A

binds to oxygen from the lungs

transports oxygen around body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what specifically travels in the phloem?

A

cell sap (sugars/salts/animo acids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

does transpiration or translocation happen in the phloem?

A

translocation (sugars moved around)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

why are cardiac muscles special?

A

they contract without receiving a nerve impulse from the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what does the vena cava do?

A

brings deoxygenated blood to the heart from the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what does the pulmonary artery do?
takes deoxygenated blood from the heart to the lungs
26
what does the pulmonary vein do?
brings oxygenated blood to the heart from the lungs
27
what does the aorta do?
carries oxygenated blood from the heart around the body
28
how is the heart depicted? (ie. ventricles on which sides)
from the patient’s point of view | so looking down at your heart your right, would be their left
29
what are the two smaller chambers at the top of the heart called?
atria
30
what are the two small chambers at the bottom of the heart called?
ventricles
31
what separate the chambers and prevent back flow?
valves
32
describe the process how deoxygenated blood becomes oxygenated
1) deoxygenated blood enters right atrium via vena cava 2) is then pumped to right ventricle when heart beats 3) pulmonary artery takes it to the lungs 4) alveoli diffuse co2 and and o2 in 5) pulmonary vein carries oxygenated blood to left atrium 6) blood pumped to left ventricle 7) aorta carries blood away to rest of body
33
why is the right ventricle wall thinner than the left ventricle?
left ventricle wall is thick to push blood around body at high pressure through aorta
34
state adaptations of red blood cells, and explain the functions
- biconcave shape (increases surface area to volume ratio, diffusion occurs faster) - no nucleus (maximum space for oxygen) - protein haemoglobin (binds to oxygen in alveoli and carries it around body) - small (to fit though capillaries)
35
state adaptations of white blood cells, and explain the functions
- can change shape easily (to engulf pathogens) - large cell - contain nucleus - creates antibodies (fight antigens on pathogens)
36
state the function of platelets
- help blood clot to prevent pathogens from entering body
37
state features of plasma
- straw coloured liquid | - 90% is water
38
what is the function of plasma?
transport materials - digested materials (animo acids/glucose) - waste (CO2) - hormones - antibodies
39
what does the xylem tissue do?
transports water + mineral ions from roots to rest of plant (stem, leaves, flowers)
40
how is water taken in from the roots?
osmosis
41
how are mineral ions taken in through the roots?
active transport
42
what does the phloem tissue transport, and where to?
- dissolved sugar molecules/ soluble food molecules | - from leaves to rest of plant
43
why are sugars taken to meristems?
- making new plant cells | - storage tissue in roots - this provides an energy store
44
how do the vascular bundles provide support in the leaf?
- form a network that supports softer leaf tissue
45
what do phloem and xylem make up together?
vascular bundles
46
state features of the xylem
- dead cells - cell wall thickened by lignin (support) - one way - no sieve plates (cells completely break down when dead)
47
state features of the phloem
- live cells - sieve plates (live cells do not completely break down) - two way flow - small holes in sieve plates (sugar to pass through)
48
how do the vascular bundles provide support in the stem?
- located around outer edge | - prevent stem from bending in wind
49
how do the vascular bundles provide support in the roots?
- in centre - root acts like anchor - root can bend as plant moves in wind
50
define transpiration
loss of water from plant’s leaves
51
describe the process of transpiration
4) Water is lost from the leaves by evaporation through open stomata 3) Water moves up through the stem and into the leaves to replace the water lost by evaporation 2) Water moves up from the roots into the stem 1) water moves into the roots from the soil by osmosis. It replaces the water constantly moving up the stem.
52
what is the transpiration stream?
constant flow of water from roots -> xylem -> leaves
53
how does water enter the xylem from root hair cells?
travels from cell to cell until reaches centre of root (where xylem is)
54
what controls the stomata from opening and closing?
guard cells
55
what happens while the stomata are open?
1) water evaporates from cells inside leaves to air space (in leaves) = CONCENTRATION GRADIENT, between air inside leaf and surrounding air 2) water vapour diffuses out of leaf into air. High—>low concentration
56
what feature on a leaf prevents uncontrollable water loss
waxy waterproof layer (cuticle)
57
how is water resupplied to the leaves?
pressure difference (sucking on a straw) - pressure low at leaves - pressure high at roots * water moves from high pressure to low pressure *
58
what causes plants to wilt?
- water lost faster than taken in
59
how does wilting help but not help a dehydrated plant at the same time?
pos - surface area reduced for evaporation - stomata closes (less water loss) neg - stomata closed prevents co2 for photosynthesis - so cannot produce enough energy
60
what tool can you use to measure how quickly a plant shoot takes + loses water?
potometer (see how much the air bubble moves)
61
what is the equation to measure the rate of transpiration?
distance travelled (mm) —————————— time (s)
62
what 4 factors affect rate of transpiration?
- light intensity - temperature - humidity - wind
63
how does light intensity affect transpiration?
- stomata stays open in light (so more water evaporates) | INCREASES
64
when does rate of transpiration reach its maximum rate (light intensity)?
all stomata are open
65
how does temperature affect transpiration?
- high temp = more evaporated (diffusion of water vapour increases) INCREASES
66
how does air movement affect transpiration?
faster air moves = faster water molecules moved - increases concentration gradient between air and leaf INCREASES
67
how does humidity affect transpiration?
more humidity = more water in air -> lower concentration gradient more water in air = less evaporation DECREASES
68
Why transpiration is beneficial to plant (4)
- provides the water for photosynthesis - transports mineral ions - cools the leaf as water evaporates - provides water that keeps the cells turgid, which supports herbaceous (non-woody) plants