AO1 - Unit 3 Flashcards
1
Q
Suggest 4 things that organisms need to exchange with their surroundings
A
oxygen, carbon dioxide, water, ions
2
Q
What happens to the SA:vol ratio as the organism gets bigger?
A
decreases
3
Q
What is the formula for the SA of a cube?
A
6a3
4
Q
What is the formula for the volume of a cube?
A
a3
5
Q
What is the formula for the SA of a sphere?
A
4?r2
6
Q
What is the formula for the volume of a sphere?
A
4/3?r3
7
Q
What is control of body temperature known as ?
A
thermoregulation
8
Q
Name two groups of organisms that maintain a constant internal body temperature
A
mammals and birds
9
Q
Define metabolic rate
A
the amount of energy expended by an organism in a given time period
10
Q
How could metabolic rate be measured?
A
respirometers
11
Q
Do elephants have a small surface area or a small SA:vol ratio?
A
small SA:V
12
Q
Name 3 types of adaptations that large animals have to lose heat?
A
large, flat ears / sweating or panting / vasodilation
13
Q
How do protoctists obtain oxygen?
A
simple diffusion
14
Q
How does being flat or hollow help multicellular organisms exchange respiratory gases
A
large SA:V so faster rate of diffusion
15
Q
How do insects reduce water loss?
A
close their spiracles, waterproof exoskeleton
16
Q
What is the difference between tracheae and tracheoles?
A
tracheae are larger and have rings of cartillage
17
Q
Why do insects close the spiracles?
A
reduce water loss
18
Q
How do some insects increase ventilation?
A
abdominal pumping
19
Q
Is water more or less dense than air?
A
more
20
Q
Does water contain more or less oxygen than air?
A
less
21
Q
Does warm water contain more or less oxygen than cold water?
A
warm has less than cold
22
Q
Is diffusion of gases faster or slower in water?
A
slower
23
Q
How is water flow across the gills of fish described?
A
counter-current system
24
Q
Name the 2 key components of the gill
A
filament and lamellae
25
What is the operculum?
gill flap
26
How are the gills adapted?
large surface area as filaments at right angles with lamallae
27
Fish have a countercurrent flow. Explain
water flows in opposite direction to blood. Maintains a concentration gradient along the whole length of the lamellae
28
Why is a countercurrent flow important?
water flows in opposite direction to blood. Maintains a concentration gradient along the whole length of the lamellae
29
How is the leaf adapted for gas exchange?
large surface area / spongy mesophyl with air spaces to maintain concentration gradient /
30
What gas is needed for leaves to photosynthesise?
carbon dioxde
31
What gas will diffuse into the palisade mesophyll cells at night?
oxygen
32
Where are stomata mainly found?
underside of leaf
33
Why are stomata present?
allows gas exchange
34
Why are stomata sometimes closed?
reduce water loss
35
What is a dicotyledonous plant?
flowering plant with two embryonic leaves
36
What is a xerophyte?
a plant adapted for dry environments
37
Describe 4 adaptations of xerophytic plants.
sunken stomata / reduced SA of leaves / hairs at stomata / thick waxy cuticle / rolled leaves
38
Describe the path of oxygen from the air to the blood in mammals
into mouth/nasal passge, down trachea, into bronchi, into bronchioles, incto alveoli, across apithelium and capillary endothelium into blood
39
What is ventilation?
breathing - movement of ribs and mucles/diaphram to increase air flow to lungs
40
Why are there rings of cartillage at the trachea?
prevent collapse
41
Why are the intercostal muscles described as antagonistic?
they work in pairs with opposite motions of contraction and relaxation
42
What happens to the volume of the thorax when the diaphragm contracts?
volume increases
43
Which intercostal muscle contracts to pull the ribs up and out?
external
44
When the volume of the thorax increases what happens to the pressure inside the thorax?
pressure decreases
45
Define tidal volume
volume of air in/out of the lungs at rest with each breath
46
How would breathing rate be measured?
spirometer - number of breaths per minute
47
How is pulmonary ventilation rate calculated?
pvr = tv x br
48
What is fibrosis?
thickening or scarring of tissue
49
Emphysema is a type of fibrosis associated with what 2 things?
alveoli and pulmonary capillaries
50
Is emphysema permanent?
yes, but symptoms can be controlled
51
Name 3 effects of emphysema
chronic coughing, shortness of breath, blueish skin
52
TB is caused by what?
bacterium - tuberculosis
53
What are the symptoms of TB?
coughing, breathlessness, tiredness and fatigue
54
What are tubercles?
small masses of tissue in the lungs
55
Does asthma lead to fibrosis?
yes
56
What happens during an asthma attack?
bronchiole mucsles constrict to reduce airflow into the alveoli and with the inflammation can come xtra mucus also
57
Name 1 cause of asthma
pollution
58
Define digestion
breakdown of larger molecules into smaller molecules
59
What are proteins hydrolysed to?
amino acids
60
What are carbohydrates hydrolysed to?
monosaccharides
61
What are lipids hydrolysed to?
glycerol and fatty acids
62
Where is gastric juice made?
stomach
63
Where is bile made?
liver
64
Where does carbohydrate digestion begin?
mouth - salivary amylase
65
What enzyme is produced by the salivary glands?
amylase
66
What is removed from polysaccharide chains by amylases?
disaccharides and monosaccharides
67
What is the first product of starch digestion?
maltose
68
What is role of maltase?
hydrolyse maltose into glucose by hydrolysing glycosidic bonds
69
What is role of lactase?
hydrolyse lactose into glucose and galactose by hydrolysing glycosidic bonds
70
What is role of sucrase?
hydrolyse sucrose into glucose and fructose by hydrolysing glycosidic bonds
71
What does bile contain?
bile salts, water and ions
72
What is role of bile?
emulsify lipids and neutralise chyme from stomach
73
What is a monoglyceride?
glycerol and one fatty acid chain
74
What is the role of an endopeptidase?
hydrolyse peptide bonds in the middle of a polypeptide chain
75
What is the role of an exopeptidase?
hydrolyse peptide bonds at the ends of a polypeptide chain
76
How are amino acids absorbed in the ileum?
co-transport with Na+
77
What occurs in the ER of the epithelial cells?
triglycerides form into chylomicrons
78
How are fats transported into the blood plasma?
small fatty acids and glycerol can be absorbed into capillaries, chylomicrons from larger fatty acids and triglycerides go into lacteals then into the blood
79
How do chylomicrons leave epithelial cells?
exocytosis
80
What do they enter after leaving epithelial cells?
lacteals
81
Define mass flow system
bulk movement of fluids down a pressure gradient
82
What type of molecule is haemoglobin?
protein
83
Why is haemoglobin described as having quaternary structure?
it have 4 polypeptide chains
84
Where is haemoglobin found?
red blood cells
85
What is the role of haemoglobin?
carry oxygen from lungs and release it to respiring cells
86
The binding of oxygen to haemoglobin is described as cooperative. Explain
when one oxygen molecule binds it causes a change in the tertiary structure making it easier for subsequent oxygen mols to bind
87
What does the oxygen dissociation curve show?
haemoglobin is more saturated with oxygen at higher partial pressures, the sigmoid curve relates to the cooperative binding in Hb
88
What is the bohr effect?
a shift to the right of the dissociation curve of haemoglobin due to an increase in carbon dioxide concentration
89
Would the haemoglobin of a lug worm have a haemoglobin with a higher or lower affinity for oxygen?
higher affinity
90
Name the artery carrying blood from the left ventricle to the body
aorta
91
Which artery carries deoxygenated blood to the lungs to pick up oxygen?
pulmonary artery
92
Which vessel carries blood from the lungs to the heart?
pulmonary vein
93
Which vessels bring the blood back to the heart from the body?
vena cava - superior and inferior
94
Which blood vessels supply the heart muscle with glucose and oxygen?
coronary artery
95
What is the function of valves?
prevent backflow
96
What are the top two chambers of the heart called?
atria
97
How is cardiac output calculated?
co = sv x br
98
Describe the 3 events during the cardiac cycle
diastole, atrial systole and ventricular systole
99
What is atheroma?
build up of fatty materials on the innder wall/endothelium of the arteries
100
Name 3 risk factors for cardiovascular disease
smoking, lack of exercise and high salt/fat diet / obesity
101
Which vessel contains valves?
veins
102
Name 2 features of capillaries
one cell thick - endothelium only, gaps called fenestrations
103
What is tissue fluid?
fluid found in the extracellular spaces surrounding tissue
104
How does tissue fluid differ from blood plasma?
no large plasma proetins or red blood cells
105
Where is tissue fluid formed?
arterial end of the cappilary bed
106
Name 2 forces involved in the formation and drainage of tissue fluid?
hydrostatic pressure and osmotic pressure
107
How does lymph differ from tissue fluid?
lymph contains fats and is held in the lymphatic vessels
108
Which tissue transports water in a plant?
xylem
109
Which tissue is responsible for the transport of organic substances?
phloem
110
What is translocation?
mass flow of dissolved sugars down a pressure gradient from source to sink
111
How is translocation explained?
mass flow hypothesis
112
Give two pieces of evidence for translocation
radio-labelled carbon dioxide experiments, pressure in aphid stylets and removal of plant tissue with phloem causes pressure build up at source end
113
What is transpiration?
movement of water through evaporation from a plant leaf
114
What is the transpiration stream?
movement of water along the xylem from the roots to the leaves of plants where evaporation occurs
115
What is unusual about the xylem?
it is dead tissue
116
What are cohesive forces?
hydrogen bonds forming between adjacent water molecules
117
How is water moved upwards in a plant?
cohesion-tension theory
118
Name 4 factors that affect transpiration?
wind speed, temperature, humidity and light intensity
119
How is transpiration measured?
potometer
