3.1.2 Transport in animals and 3.1.3 transport in plants Flashcards
1
Q
what type of circulatory system do mammals have
A
double circulation
2
Q
function of heart
A
generate blood pressure
3
Q
function of blood vessels
A
maintain and regulate pressure
4
Q
function of pulmonary capillary bed
A
exchange surfaces
5
Q
function of systemic capillary bed
A
exchange surfaces
6
Q
what are the 3 circulatory fluids
A
blood
tissue fluid
lymph
7
Q
function of blood
A
to transport O2, CO2 and waste products
maintains body temp
8
Q
function of tissue fluid
A
fill space between cells and helps with diffusion between blood & cells
9
Q
function of lymph
A
manage fluid levels in the body
10
Q
what happens in capillary beds
A
transport and exchange gases, fluids and nutrients in the body
11
Q
5 types of blood vessels
A
artery
arteriole
capillary
vein
venule
12
Q
3 layers of blood vessels
A
tunica media
tunica externa
tunica intima
13
Q
collagen
A
structural support
maintains shape and volume
14
Q
smooth muscle
A
changes size of lumen
contrats + relaxes
15
Q
elastin
A
flexible
strech + recoil
16
Q
squamous epithelium
A
flat and thin to allow molecules to pass in diffusion
17
Q
function of coronary artery
A
supply O2 to heart muscle
18
Q
cardiac cycle definition
A
one complete sequence of relaxation and contraction
19
Q
what causes the lub dub sound of the heart beat
A
opening and closing of valves
20
Q
3 stages of cardiac cycle
A
atrial systole
ventricular systole
diastole
21
Q
Diastole
A
all chambers are relaxed
semi lunar valves close
dub sound
22
Q
atrial systole
A
AV valves open
pressure in atria is greater than in ventricle
blood is forced out atria into ventricle
23
Q
ventricular systole
A
AV valves close
lup sound
pressure in ventricles is higher than in aorta and pulmonary artery
semiluanr valves open and blood is forced out
24
Q
what causes heart to contract
A
SAN sends impulse that spreads throughout atria causing it to contract
AVN recieves electrical impulse from SAN node causing slight delay then sends impulse to bundle of His
bundle of his sends impulse to apex of heart
this sends impulse up through ventricle so all blood is forced out
25
why is theyre a delay between SAN node and Avn recieving impulse
allows atria to completely contract and empty
26
why do plants need transport systems
metabollic demands
size
surface area to volume ratio
27
what metabollic demands do plants have
cells make there own glucose and O2 but underground parts need it transported to them and remove waste products
28
what do valves do
prevent backflow of blood
29
why does size effect if a plant needs a transport system
some plants continue to grow throughout there life and become large so need a system to move substances from roots to leaves
30
how does surface area to volume ratio effect if plant needs transport system
leaves have large SA:volume ratio but stem have small so cant rly on diffusion alone
31
route of blood
deoxygenated blood enters right atria via vena cava
right ventricle
pulmonary artery
lungs
pulmonary vein
left atria
left ventricle
aorta to body
32
what is the exodermis
outside of root
33
where is exodermis found
root only
34
what is the epidermis
outermost layer that covers stem, leaves, flower and seeds
35
where is epidermis found
root and stem
36
what is the cortex
unspecialised cell lying between the epidermis and vascular tissue of stem and roots
37
where is cortex found
root and stem
38
what is the endodermis
cyclindrical boundary that seperates vascular tissue from outer cortex
39
structure and function of xylem
non living tissue
transport water and mineral ions
flows material up from root to leaves and shoot
40
types of xylem tissue
lignified
bordered pits
xylem vessels
xylem parenchyma
xylem fibres
41
what does the xylem being lignified do
provides mechanical strength and resistance against pathogens
can be in rings, spiracles or solid tubes
42
what do bordered pits do
lets water leave xylem and enter into other cells
43
xylem vessels
main structure
long hollow structures made of several colomns of cells
44
xylem parenchyma
thick walled surrounding vessels to store food
45
xylem fibres
long cells lignified secondary walls that provide extra mechanical strength but dont transport water
46
adaptations of xylem tissue
wide hollow vessels
walls impregnated with ligment
lignin laid in spiral pattern
bordered pits in wall
continuous vessels- no end walls
47
why does xylem have wide hollow vessels
more water can be transported
48
why are xylem walls impregnated with lignin
extra mechanical strength
49
why does xylem have lignin laid in spiral pattern
helps reinforce vessel so doesnt collapse under water pressure
50
why does xylem have contiuous vessels
so flow of water isn't slowed
51
function of phloem
transport sucrose/sugars around the plant from the leaves
52
structure of phloem
living
transports materials up and down
53
what do sieve tube elements in phloem do
made of many cells joined end to end to form long hollow structure
not lignified
54
what do sieve plates do in phloem
let phloem contents flow through
55
components of blood
red blood cell
platelets
white blood cells
plasma
56
white blood cells
involved in the immune system + defending against infections
many different types
57
plasma
yellow liquid
makes up 55% of blood
carries dissolved glucose, amino acids, mineral ions, hormones and large proteins
Albumin
Fibrogen
Globulin
58
red blood cells
bioconcave shape
no organelles
lots of haemoglobin
carry O2 around body
59
where is tissue fluid formed
artial end of capillary bed
60
where is tissue fluid reabsorbed
venous end of capillary bed
61
oncotic pressure
tendency of water to move into the blood by osmosis
62
what is tissue fluid
fluid fills the spaces between the cells
63
why is Bohr effect important
in active tissues with high partial pressure of CO2 haemoglobin gives up oxygen more readily
in the lungs where CO2 is low oxygen binds to haemoglobin molecules more readily
64
why does fetal haemoglobin have a higher affinity for oxygen than adult haemoglobin
as it can then remove oxygen from maternal blood as they move past each other
if they had the same affinity as adult then little to no oxygen would be transferred
65
what are the 3 ways that CO2 is transported from the tissues to the lungs
in the plasma
as carbaminohaemoglobin- combined with amino acidss in chain of haemoglobin
converted into hydrogen carbonate ions in the cytoplasm of red blood cells
65
66
chlorine shift
negative HCO3 - ions move out of erythrocytes into plasma by diffusion and negatively charged Cl- ions move into the erythrocyte to maintain electrical balance of the cell
67
what happens in diastole
heart relaxes
atria and ventricles fill with blood
volume and pressure of blood in heart builds as heart fills
pressure in arteries is at a minimum
68
what happens in systole
atria contract and closely followed by ventricles contracting
pressure inside heart increases
blood is forced out of right side of heart to lungs and from left side to the body
volume and pressure in heart at the end is low and blood pressure in arteries is at maximum
69
what makes the lub- dub sound
lub = blood forced against AV valves as ventricles contract
dub = backflow of blood closes semi-lunar valves in aorta and pulmonary artery as ventricles relax
70
myogenic definition
muscle that has its own intrinsic rhythm
71
what initiates the heart beat
SAN - sino-artial node
72
what causes the heartbeat
SAN releases a electrical impulse causes atria to contract
This is then goes to the AVN which causes a delay before sending it to the bundle of His which causes a contraction from the apex of the heart in the ventricles
73
why does the heart contraction start at the apex of the heart
allows more efficient emptying of the ventricles
74
why is there a delay at the AVN
to allow the atria to stop contracting and completely empty before the ventricles start
75
what is tachycardia
when heartbeat is very rapid - over 100 bpm
normal for exercise, if have fever, scared or angry
abnormal - may be caused by problems in the electrical control of the heart and may need surgery to fix
76
what is bradycardia
when heart rate slows to below 60 bpm
many people have it if they're fit as the heart works slower and more efficient
severe cases can be serious and require an artificial pacemaker to keep the heart beating steadily
77
what is ectopic heartbeat
extra heartbeats out of normal rhythm
usually normal but can be linked to serious conditions if more frequent
78
atrial fibrillation
abnormal rhythm of the heart
rapid electrical impulses generated in atria so contract very fast- up to 400 times a minute
they don't contract properly so only some of the impulses are passed onto ventricles so blood isn't pumped effectively
79
root hair cells
exchange surface in plants where water is taken into the body
80
adaptations of root hairs
microscopic size means they can penetrate easily between soil particles
each hair has large SA:V ratio - thousands on each growing root tip
thin surface layer for short diffusion and osmosis pathway
conc of solutes in the cytoplasm of root hair cell maintains a water potential gradient between soil water and the cell
81
symplast pathway
- moves through continuous cytoplasm of the living plant cell that is connected through the plasmodesmata by osmosis
- root hair cell has higher water potential than next cell along so water moves by osmosis
- continues until xylem is reached
82
apoplast pathway
- through the cell walls and the intercellular spaces
- water fills spaces between the loose,open network of fibres in the cellulose cell wall
- as water molecules move into xylem more water molecules are pulled through apoplast due to the cohesive forces between the water molecules
- the pull with cohesive forces creates tension so there's a continuous flow of water through the open structure of the cellulose cell wall which offfers little to no resistance
83
what is the casparian strip
a band of waxy material called suberin that runs around each of the endodermal cells forming a waterproof layer
84
steps for movement of water into the xylem
water moves across the apoplast and symplast pathway until it reaches the endodermis- the layer of cells surrounding the vascular tissue of the roots
- when it reaches the casparian strip water in apoplast pathway can't move any further so forced into symplast pathway to do this it passes through the partially permeable membrane
- solute conc in cytoplasm of endodermal cells is dilute compared to cells in xylem so water potential of xylem is lower than the endodermal cells so this increases rate of water moving into the xylem by osmosis
- once in vascular bundle it moves through apoplast pathway to enter the xylem
85
what causes water to move up the xylem
root pressure
86
2 types of transport vessels in plants
xylem
phloem
87
what makes up the vascular bundle
xylem and phloem
88
what is the exodermis
outside of the cell
89
what is the cortex
unspecialised cells lying between epidermis and vascular tissues of stem and roots
90
what does xylem transport
water and mineral ions
90
what is the endodermis
cyclindical boundary that seperates the vascular tissues from outer cortex
90
whats unusual about the xylem tissue
non-living
91
function of bordered pits in fully lignified vessels
where water leaves xylem and moves into other cells
92
function of lignin in the xylem
to provide mechanical strength and resistance against pathogens
93
xylem parenchyma
store water and food
thick walled surrounding the vessels
94
function of wide hollow vessels in xylem
lots of water can be transported
95
function of walls impregnated with lignin in xylem
provide extra mechanical strength
96
function of lignin laid down in spiral pattern in xylem
helps reinforce the vessel so it doesn't collapse under pressure
97
function of vessels being continuous in xylem
so flow of water isn't slowed
98
what does phloem transport
food in the form of organic solutes around plant from the leaves
99
what do plants do with the sugars supplied by the phloem
used in cellular respiration and for synthesis of all other useful molecules
99
which direction does the transport of molecules in the phloem go
up and down
100
structure and function of sieve plates
look like sieves
allow contents to flow through
large pores in cell wall
101
structure and function of plasmodesmata
micoscopic channels through the cellulose cell wall linking the cytoplasm of adjacent cells
102
structure and function of sieve tube cells
made of many cells joined ened to end to form a long hollow structure
103
are sieve tube elements lignified
not lignified
104
structure and function of companion cells
closely linked to sieve tube elements
have nucleus and organelles
105
why do sieve tubes have little cytoplasm
so more sugars can be pumped through
106
what is transpiration
the evaporating of water from the aerial part of the plant
107
what can stomata do to control water loss by transpiration
guard cells to open and close them
108
why do some stomata need to be open all the time
for gaseous exchange
109
shape and structure of guard cell
kidney beaned shape
highly thickened inner wall which causes them to inflate asymetrically
110
mechanism of closing stomata
- active transport of K+ ions ceases
-K+ ions move back out of cell by facilitated diffusion
-this increases the water potential in guard cells
111
mechanism of opening stomata
-K+ ions are actively transported into the guard cell lowering the water potential
-water is moving into guard cell by osmosis down water potential gradient
-they swell with water causing stoma to appear
112
transpiration stream
113
what is translocation
transport of assimulates from source to sink
114
what is transported in the phloem
sucrose
amino acids
hormones
115
how is th energy requirement for translocation different than water transport
active process so requires energy in form ATP
116
example of source
leaf
117
example of sink
meristem
118
steps for active phloem loading
- proton pump moves H+ ions against conc gradient out of companion cell
-conc gradient for H+ ions is created
- H+ and sucrose move into companion cell down a conc gradient
-sucrose is going against a conc gradient
119
what is mass flow
bulk movement down a pressure gradient
120
explain the difference between a source and a sink
source is the supplier of sugars such as the leaves
sink is where the sugar goes such as the roots or growing tip
121
arterioles structure
thicker smooth muscle layer than arteries to help restrict blood flow into capillaries
elastic layer thinner than arteries as lower pressure
thinner collagen layer
thinner walls
122
arteries structure
thick smooth muscle layer so constriction and dilation can occur
thick elastic layer to help maintain blood pressure and walls to stretch and recoil
thick walls to maintain blood pressure
collagen outer layer to provide structural support
123
veins structure
relatively thin smooth muscle layer so can't control blood flow
relatively thin elastic layer as low pressure
contains lots of collagen
thin walls due to low pressure so low risk of bursting
contains valves
124
capillaries structure
1 cell thick for short diffusion distance for gas exchange
125
cardiac output equation
HR x Stroke volume
126
what is cardiac output
volume of blood that leaves one ventricle in one minute
127
what is oncotic pressure
tendency of water to move into blood by osmosis
128
what does coronary arteries do
supply cardiac muscle with oxygenated blood for aerobic respiration to provide ATP so it can continuously contract and relax
129
why is left ventricle muscular wall thicker
so can contract with more force to pump blood at high pressure all around the body
