B4- Organising animals and plants Flashcards
1
Q
What do multicellular organisms with a small surface area to volume ratio often have?
A
often have trasnport systems
2
Q
What 3 components is the circulatory system consist of?
A
blood
blood vessels
and the heart
3
Q
What is the liquid your blood is pased on?
A
Plasma
4
Q
What does plasma carry?
A
RBCS, WBCs and platelets suspended in it
5
Q
What does Plasma also do
A
Carries many dissolved substances around your body
6
Q
The average person has how many litres of blood?
A
4-5
7
Q
What is a platelet
A
small fragments of cells
8
Q
What does the plasma transport around your body
A
blood cells and some other substances around your body
9
Q
Give three examples of what the plasma has to carry
A
Waste carbon dioxide
Urea formed in the liver
small, soluble products of digestion
10
Q
Expand on how CO2 is carried in the blood
A
Waste CO2- produced by cells- carried to the lungs
11
Q
Expand on how urea is carried in the blood
A
Urea- formed in liver from breakdown of EXCESS PROTEINS- carried to KIDNEY where it is removed from your blood to form urine
12
Q
Expand on how small, soluble products of digestion is carried in the blood
A
small, soluble products of digestion pass into the plasma from small intestine and are transported to individual cells.
13
Q
There are more __ ____ ___ than any other type of ___ cell in your body. About _ ____ in each cubic mm of blood
A
i) red blood cells
ii) blood
iii) 5 million
14
Q
What do red blood cells do?
A
pick up oxygen from the air in your lungs and carry it to the cells where it is needed
15
Q
What adaptations do red blood cells have?
A
Is a biconcave disc
Packed w haemoglobin
no nucleus
16
Q
Why are they biconcave discs?
A
Being pushed in on both sides- increased sa to v ratio for DIFFUSION
17
Q
Why are they packed with a red pigment called haemoglobin?
A
BINDS to oxygen
18
Q
What;s the red pigment in the red blood cell?
A
haemoglobin
19
Q
Why do they have no nucleus?
A
more space for haemoglobin
20
Q
TRUE/FALSE WBCs are bigger than RBCs
A
True
21
Q
TRUE/FALSE There are less WBCs than RBCs
A
true
22
Q
What does a WBC have that a RBC doesnt?
A
A nucleus
23
Q
What is the term given for the WBC that form antibodies against microorganisms?
A
lymphocytes
24
Q
What do some white blood cells form? (lymphocytes)
A
antibodies
25
What do WBCs form?
part of the body's defence sstem against harmful micro-organisms
26
What else do some WBC's do?
form antitoxins against POISONS made by microogranisms
27
Yet others (phagocytes) what do these type of WBCs do?
engulf and digest invading bacteria and viruses
28
What can WBC's do?
Some- form antibodies against microorganisms
Some- form antitoxins against poisons made by microogranisms
Some- engluf and digest invading bacteria and viruses
29
What do platelets not have?
A nucleus
30
Why are platelets very important?
helping the blood to clot at the site of a wound
31
What is blood clotting
a series of enzyme-controlled reactions that result in converting fibrinogen into fibrin. This produces a network of protein fibres that catches lots of red blood cells and more platelets to form a jelly-like clot that stops you bleeding to death. The clot dries and hardens to form a scab
32
After a series of enzyme-controlled reactions that result in converting fibrinogen into fibrin is produced (blood clotting) what happens?
This produces a network of protein fibres that catches lots of red blood cells and more platelets to form a jelly-like clot that stops you bleeding to death.
33
After the jelly-like clot is produced from the fibres catching it, what happens now?
The clot dries and hardens to form a scab
34
What does scabbing protect?
The new skin as it grows and stops bacteria entering the body through the wound
35
Red blood cells, white blood cells and platelets are suspended where?
In the blood plasma
36
Blood is carried around your body in three main types of blood vessels. What are they?
Arteries
Veins
Capillaries
37
What is a way to remember what a blood vessel is?
Vessel- container or think of it as the tube
| Container carries blood
38
What does your artery do?
carries blood AWAY from the HEART to the organs of your body
39
What does your veion do?
carries blood AWAY from the ORGANS TOWARDS your heart
40
What do capillaries do?
Form a huge network of tiny vessels linking the ARTERIES and the VEINS
41
What sort of blood is the artery?
bright-red oxygenated blood
42
What sort of blood is the veins
Usually low in oxygen- purple-red colour
43
What do vein do not have?
A pulse
44
What sort of walls do veins have?
Thin walls
45
What do veins often have and why?
Valves to prevent backflow of blood
46
How is the blood squeezed back towards the heart in the veins?
by the action of the skeletal muscles
47
What do the arteries do as the blood is forced through them?
They stretch and then go back into shape afterwards (reference pulse)
48
Arteries have ____ walls containing ____ and _____ ____
i) thick
ii) muscle
iii) elastic fibres
49
Why is it very dangerous if an artery is cut?
Blood in arteries- under presssure
| Blood will spurt out rapidly every time the heart beats
50
Capillaries are _____ with very ___ walls
narrow
| thin
51
What does the thin walls allow capillaries to do?
enables sunstances such as oxygen and glucose to DIFFUSE easily out of the blood and into the cells
52
The substances produced by your cells such as CO2 can do what?
pass easily into the blood through the walls of the capillaries
53
How are the blood vessels arranged?
In a double circulatory system
54
Name the two transport systems
1. carries blood from heart -> lungs and back again
| 2. carries blood from heart to all other organs of your body and back again
55
carrying blood from heart to lungs allows what?
oxygen and carbon dioxide to be exchanged with the air in the lungs
56
Where does the fully-oxygenated blood travel?
returns to the heart from the lungs
57
Where can fully oxygenated blood be sent off to?
Different parts of the body at high pressure
58
Why is fully oxygenated blood sent off to different parts of the body at high pressure?
More areas of your body can receive fully oxygenated blood quickly
59
What organ pumps blood around your body?
The heart
60
Why is the circulation around the body is made up of two pumps?
double circulation
61
The walls of your heart are almost entirely made of what?
Muscle
62
The muscles of the heart are supplied with _____ by the what?
oxygen
| coronary arteries
63
What is the structure of the heart perfectly adapted for?
pumping blood TO your lungs and body
64
What do the two sides of the heart do?
fill and empty a the same time, giving a strong, coordinated heartbeat
65
Where does the blood enter?
the top chambers of the heart
| ATRIA
66
The blood coming into the right atrium from the _____ ___ is deoxygenated blood from your body
vena cava
67
The blood coming into the left artrium in the ____ ___ is oygenated blood from you ____
pulmonary vein
| lungs
68
What does the atria do?
contract together and force blood down into the ventricles
69
What do valves do?
stop the blood flowing backwards
70
What is the function of the ventricles?
contract and force blood out of the heart
71
What does the right ventricle do?
forces deoxygenated blood to the lungs in the pulmonary artery
72
What does the left ventricle do?
Pumps oxygenated blood around the body in a big artery called the aorta
73
What happens as blood is pumped into the pulmonary artery and the aorta?
valves close to make sure the blood flows in the right direction
74
The pulse is the...
sound of valves closing to prevent blood from flowing backwards
75
Why is the muscle wall of the left ventricle noticeably thicker?
Allows left ventricle to develop the pressure needed to force the blood through the arterial system all over the body
76
The blood leaving the right ventricle moves through the _____ ______ to your lungs where ____ ____ would _____ the delicate _____ network where __ ______ takes place
i) pulmonary arteries
ii) high pressure
iii) damage
iv) cappilary
v) gas exchange
77
Vena cava brings _______ blood INTO the HEART
deoxygenated
78
Pulmonary artery takes _______ blood TO the LUNGS
deoxygenated
79
Aorta carries _____ blood AROUND the BODY
oxygenated
80
Pulmonary veins bring ______ blood FROM the LUNGS
oxygenated
81
LEFT SIDE OF HEART= OXYGENATED BLOOD
RIGHT SIDE OF HEART=DEOXYGENATED BLOOD
82
What is on the right side of the heart?
pulmonary artery
vena cava
right atrium
right ventricle
83
What is on the left side of the heart?
aorta
pulmonary vein
left atrium
left ventricle
84
REMEMBER THE TOP STRUCTURES OF THE HEART IS FOR DOUBLE CIRCULATION- TOWARDS IT
pulmonary artery- to the lungs
| Aorta- around the body
85
What happens to the coronary arteries that supply blood to the heart muscles in coronary heart disease?
the coronary arteries become narrow
86
Common cause of coronory heart disease?
buildup of fatty material on the lining of the vessels
87
What happens if the blood flow through the coronary arteries is reduced?
supply of oxygen to the heart muscle is also reduced- causing pain, a heart attack or even death
88
How may doctors often solve the problem of coronary heart disease?
A stent
89
What is a stent
metal mesh that is placed in the artery
90
How is a stent injected?
A tiny ballon is inflated to open up the blood vessel and the stent at the same time.
Balloon- deflated + removed but stent reminds in place, holding the blood vessel opened. As soon as this is done. the blood in the coronary artery flows freely.
91
What is an adv. of a stent
Doctors can put a stent in place without a general anesthetic
92
What happens after a tiny balloon is inflated to open up the blood vessel and the stent?
the balloon is deflated and removed but the stent remains in place. holding the blood vessel open
93
Stents can be used how?
to open up a blocked artery almost naywhere in the body
94
What do many stents release?
drugs to prevent the blood clotting
95
Doctors can also carry out ___ surgery; what does this concern?
bypass surgery
| replacing the narror or blocked coonary arteries w/ bits of veins from other parts of the body?
96
what does bypass surgery work for?
badly blocked arteries where stents cannot help
97
What is the disadv. of bypass surgery
expensive and involves a risk associated with a general anaesthetic
98
What do statins do?
reduce blood cholersterol levels- slows don rate at hich fatty materials is desposited in the coronary arteries
99
Heart valves have to withstand what
a lot of pressure
100
Overt time, what might happen to the valves?
start to leak, or become stiff and not open fully; less efficient hearts
101
true/false doctors cannot operate and replace fualty heart valves
false
102
What are mechanical valves made of?
titanium and polymers
103
What is a adv. of mechanical valves?
Last a v long time
104
What is a disadv. of mechanical valves?
take medice for the rest of your life to prevent blood from clotting around it
105
What are biological valves based on?
valves taken from animals such as pigs or cattle, or even juman donors
106
What is an adv. and disadv. of biological valves?
no need for any medication
| but only lasts 12-15 years
107
What is the resting rhythm of a healthy heart?
Around 70 beats a minute
108
What is the resting heart beat controlled by?
a group of cells found in the right atrium of your heart that acts as your natural pacemaker
109
what happens when a persons heart rate is too slow
not get enough oxygen
110
what happens when a persons heart rate is too high
cannot pump nlood properly
111
how may problems with the rhythm og the heart can be solved
with an artificial pacemaker
112
What is an artificial pacemaker?
an electrical device used to correct irregularities in the heart rate
113
Where is an artificial pacemaker planted?
in the chese
114
how much do artificial pacemakers weigh?
between 20 and 50g
115
How are artificial pacemakers attached?
attached to the heart by two wires
116
What do artificial pacemakers do?
send strong, regular electrical signals to your heart that stimulate it to beat properly
117
Modern pacemakers are often sensitive to what?
to what your body needs and only work when the natural rhythm gies wrong
118
If you have a pacemaker fitted, what is a consequence?
regular medical check-ups
119
why may an artificial heart be used rather than a pacemaker?
is not enough to restore a person's health
120
When people need a heart transplant, what do they have to wait for?
a donor heart that is a tissue match
121
What do artificial hearts need a lot of?
machinery to keep them working
122
What risk is there of having an artifical heart?
risk of blood clotting
123
what can artificial heats also be used for?
to givea diseased heart a rest so that it can recover
124
why are artificial hearts not widely used?
very expensive
125
What must you need for a gas exchange system to work efficiently?
a large difference in cncentrations of the gas on different sides of the exchange membrane
126
a large difference in cncentrations of the gas on different sides of the exchange membrane. What does this mean?
a steep conc. gradient
127
How may humans maintain a steep conc. gradient?
By changing the composition of the air in the lungs, they maintain a steep concentration gradient for both ocygen diffusing into the blood and co2 diffusing out of the blood
128
Where are your lungs found and protected?
in the chest and protected by the ribcage
129
Where are the lungs seperated?
from the digestive organs beneath (in your abdomen) bu the diaphragm
130
What is the diaphragm?
strong sheet of muscle
131
What is the job of the ventilation system?
to move air in and out of lungs- providing an efficient surface for gas exchange in the alveoli
132
How is ventilating the lungs brought about by?
contraction and relaxation of the intercostal muscles between the ribs and the diaphragm
133
What does the contraction and relaxation of intercostal muscles do?
changes pressure inside the chest cavity so air is forced in or out of the lungs as a result of differences in pressure
134
What happens when you breathe?
oxygen rich air moves into your lungs
135
What does 'oxygen-rich air moving into your lungs' maintain?
maintains a steep conc. gradient with the blood
136
What is the result of a steep concentration gradient with the blood?
oxygen continually diffuses into your bloodstream through the gas exchange surfaces of your alveoli
137
What does breathing out do?
removes carbon-rich air from the lungs
138
What does 'removes carbon-rich air from the lungs' maintain?
maintains a concentration gradient so CO2 can continually diffuse out of the blood stream into the air in the lungs
139
Why is a concentration gradient maintained when breathing out?
CO2 can continually diffuse out of the blood stream into the air in the lungs
140
What is the percentage of air breathed in by nitrogen oxygen and co2 and air breathed out?
nitrogen- both 80%
oxygen- 20% breathed in 16% out
coz- 0.04% breathed in, 4% breathed out
141
Your lungs are specially adapted to make what?
gas exchange more efficient
142
What are the lungs made up of?
clusters of alveoli that provide a very large surface area
143
Why is a large surface area important for the alveoli?
most effective diffusion of carbon dioxide and oxygen
144
What does the alveoli have a rich supply of?
blood capillaries
145
Having a rich blood supply of blood capillaries does what?
maintains a conc. gradient in BOTH directions
146
The ___ coming to the lungs is always relatively __in ____ and high in ______ ____ compared to the ____ air
i) blood
ii) low
iii) oxygen
iv) carbon dioxide
v) inhaled
147
As a result, where does gas exchange takes place down?
the steepest concentration gradients possible
148
Why does gas exchange take place in the steepest conc. gradients possible?
Makes exchange rapid and effective
149
Why might the layer of cells between the air in the lungs and the blood in the capillaries very thin and how thin?
one cell wide
| Allows diffusion to take place over the shortest possible distance
150
What happens if all of the alveoli in your lungs were spread flat?
they would have a surface area equivalent to 10-15 table tennis tablets
151
What does a good blood supply maintain?
concentration gradient for DIFFUSION by removing oxygen and bringing lots of carbon dioxide
152
What does ventilation do?
moves air in and out and helps maitain a steep diffusion gradient
153
What do the very thin alveolus walls do?
short distance between air and blood- make diffusion east
154
Why does the alveolus have a spherical shape??
gives relatively large SA for diffusion
155
What do epidermal tissues do?
cover the surfaces and protect them
156
What do epidermal cells often secrete?
a waxy substance that waterproofs the surface of the leaf
157
What does palisade mesophyll tissue contain?
lots of chloroplasts to carry out photosynthesis
158
Spongy mesophyll tissue contains what?
some chloroplasts for photosynthesis but also has big air spaces and a large SA for diffusion of gases easier
159
What are xylem and phloem ?
the transport tissue in plants
160
What does xylem carry?
water and dissolved mineral ions from the ROOTS up to the LEAVES
161
Phloem carries what?
dissolved food from the LEAVES around the PLANT
162
Where is the meristem tissue located?
Growing tips of roots and shoots
163
What is the meristem tissue made up of?
rapidly dividing plant cells that grow and differentiate into all the other cell types needed
164
Leaves, stems and roots are all categorised into what?
plant organs
165
What does the stomata do?
allow gases to move in and out of the leaf
166
guard cells, what do they do?
control the opening and closing of the stomata
167
Plants make ______ by photosynthesis in the ____ and other green parts
glucose
| leaves
168
Where is glucose needed in the plant?
all over
169
Water and mineral ions move into the plant from the soil through the roots, but they are needed where?
by every cell of the plant
170
What does the phloem do?
transport the sugars made by photosynthesis from the leaves to the rest of the plant?
171
What does the transportation of sugars by the phloem also include?
transport to the growing areas of the stems and roots where the dissolved sugars are needed for making new plant cells.
172
Where is food also transported to?
the storage organs where it provides an energy store for the winter
173
Phloem is a _____ tissue- the phloem cells are ____
living
| alive
174
What is translocation?
the movement of dissolved sugars from the leaves to the rest of the plant
175
Greenfly and other aphids are what?
plant pests
176
What do plant pests do?
push their sharp mouthparts right into the phloem feed on the sugary fluid
177
Mature xylem cells are _____
dead
178
In woody plants like trees, what does the xylem make up?
the bulk of wood
179
Where is the phloem found in the tree?
in a ring just underneath the bark
180
How might young trees be particularly vulnerable to damage by animals?
If a complete ring of bark is eaten, transport in the phloem stops and the trees will die
181
What are elephant yams?
plants that produce a large flower that releases a disgusting stench like rotten meat that attracts carrion beetles
182
What happens to trapped insects in elephant yams?
trapped in flower
slippery, waxy walls stop them escaping
Day later- pollen coats beetles and they are able to escape for reproduction
183
What sort of specialized cells are within the body of the plant and are arranged to form organs
palisade, spongy mesophyll, xylem, and phloem
184
Give an example of a plant with a specialized defense tissue or organ
nettles have specialized hairs that act like hypodermic needles, injecting poison into any animal brushing past or attempting to eat them
185
What does mesophyll tissue do?
carry out photosynthesis
186
Why is it vital to move the food made by photosynthesis around the plant?
all the cells need sugars for respiration as well as for providing materials for growth
187
Why is the movement of water and dissolved minerals from the roots really important?
the mineral ions are needed for the production of proteins and other molecules within the cells
188
Why may a plant need water?
photosynthesis
| hold itself upright
189
Why may water hold the plant upright
plenty of water- vacuole presses the cytoplasm against cell walls, pressure of cytoplasm against cell walls gives support for young plants and for the structure of the leaves
190
Explain why a plant needs a transport system
transport of food made in leaves and water and mineral ions taken from soil to rest of plant
191
Describe the differences between xylem and phloem in a plant
Mature xylem- dead, found on inside of vascular bundles, water + mineral ions
Phloem-living, on the outside, glucose/ dissolved sugars
192
How may protecting bark allows a forest to grow?
Phloem in trees found in a ring just underneath bark.
Soft bark of young trees vulnerable to damage by animals.
If complete ring of bark is eaten, transport of water from roots and
sugars from leaves stops and young tree will die.
Plastic covers protect young bark from animals.
Covers can be removed once trees are more mature and bark is harder.
If covers aren’t used, most of young trees are likely to be destroyed and
woodland will eventually die as old, mature trees are not replaced.
193
What sort of system does plants have?
separate transport system
194
All over the leaf surface, there are small openings known as what?
stomata
195
When can the stomata be opened?
when the plant needs to allow air into the leaves
196
What diffuses into the air spaces (stomata) and then into the cells down a concentration gradient?
Carbon dioxide
197
What happens at the same time as CO2 diffuses into the stomata
oxygen produced by photosynthesis is removed from the leaf by diffusion into the surrounding air
198
As CO2 is let in and O2 is diffused out, what does this maintain?
maintain a concentration gradient for oxygen to diffuse from the cells into the air spaces of the leaf
199
What is the size of the stomata and their opening and closing controlled by?
the guard cells
200
What also happens when the stomata is opened?
plants lose water vapor through them
201
How does the plant lose vapour through the stomata?
water vapour evaporates from the cells lining the air spaces and them passes out of the leaf through the stomata by diffusion
202
What is the loss of water vapour known as?
transpiration
203
What happens as water evaporates from the surface of the leaves
More water is pulled up through the xylem to take up its place
204
What is the constant movement of water molecules through the xylem from the roots to the leaves called?
transpiration system
205
What is the transpiration system driven by?
the loss of water by evaporation of water from the leaves, out of the stomata
(anything that affects the rate of evaporation will also affect transpiration)
206
Where is most of the water vapor lost in plants?
from the leaves
207
Why is it important that plants can close the stomata?
to limit the loss of water vapour
208
Explain how water moves up a plant in the transpiration stream
As water evaporates from leaf surface, more water is pulled up through
xylem to replace it.
Water moves into roots by osmosis to replace water moving up xylem.
Transpiration stream is constant movement of water molecules through
xylem from roots to leaves.
209
Describe the process of transpiration
Water vapour evaporates from cells lining air spaces
and diffuses out of leaf through stomata
down a concentration gradient
210
Why is it that anything that increases the rate of photosynthesis, will increase the rate of transpiration?
more stomata open up to let in carbon dioxide and when the stomatas are open, the rate at which water is lost by evaporation and diffusion increases
211
Which conditions increase the rate of transpiration
hot, dry and windy conditions
212
Why does hot,dry and windy conditions increase rate of transpiration?
more water evaporates from the cells and diffusion happens quicker
213
How may wind increase the rate of evaporation and maintain a steep concentration gradient?
removing water vapour as it diffuses out
214
How may temp. affect the rate of transpiration
increase in temp= diffusion occurs more rapidly (molecules move faster)
rate of photosynthesis also increases- more stomata will be open for gas exchance
215
What 3 conditions affect the rate of transpiration
How windy it is
Temperature
How hot and dry it is
216
What adaptation do most leaves have?
a waxy, waterproof layer (the cuticle) to prevent uncontrolled water loss
217
Where are most of the stomata found in leaves and why?
underside of the leaves- protects them from the direct light and energy of the sun
218
What happens if a plant begins to lose water faster than it is replaced by the roots?
The whole plant may wilt- protection mechanism against further water loss
(leaves collapse and hang down, greatly reduces the surface area available for water loss by evaporation)
219
If a plant begins to lose water faster than it is replaced by the roots, the stomata...
closes- stops photosynthesis and risks overheating
| This prevents most water loss and any further wilting
220
What can a potometer be used for?
to show how the uptake of water by a plant changes in different conditions
221
What does using a potometer give a good idea of?
the amount of water lost by the plant in transpiration
222
Almost all of the water taken up by a plant is lost in transpiration, but a small amount is used in what?
metabolism, for example, photosynthesis
223
Name the parts of the leaf that help the plant to reduce water loss under normal conditions
waxy cuticle
| guard cells
224
Describe the effect on plant transpiration of coating the top surface of the leaves in petroleum jelly
Petroleum jelly on top surface has little effect as few stomata covered.
Most stomata are found on underside of leaves and would be
unaffected.
225
Why may water lillies have their stomata on the tops of their leaves
Stomata on underside would be under water and water could not be lost
through them.
Stomata on top surface enable effective gas exchange for
photosynthesis through direct exposure to sunlight.
