Module 3 Bio

  • Created by: Jessinoch
  • Created on: 06-05-18 20:39
What is needed for an efficient exchange surface?
1. Large Surface 2. Thin barrier 3. Maintains steep diffusion gradient
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How does air get from the airways to the alveoli?
Airways -> Lungs -> Trachea -> Bronchi -> Bronchioles -> Alveoli
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What is cartilage used for?
For support & to keep airways open preventing collapse
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What are cilia used for?
Wafts mucus containing bacteria
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What are goblet cells used for?
Seretes mucus to trap bacteria and pollen
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What is smooth muscles used for?
Able to contract involuntarily, restricting the air flow and preventing harmful substances from getting in
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What are elastic fibres used for?
Stretch and recoil, helping to dilate airway
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Describe inhalation
1. External intercostal muscles contract 2. Diaphragm contracts & flattens 3. Ribs move up and out 4. Volume increases 5. Pressure decreases 6. Air moves from high to low pressure 7. Lungs expand 8. Air is inhaled
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Describe exhalation
1. External intercostal muscles relax 2. Diaphragm relaxes & arches 3. Ribs move down and in 4. Volume decreases 5. Pressure increases 6. Air moves from high to low pressure 7. Lungs deflate 8. Air is exhaled
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Define tidal volume
Largest volume of air that can be moved in and out of the lungs in one breath
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Define breathing rate
Number of breaths per minute
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Define oxygen uptake
Measure of volume of oxygen inhaled per unit time
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What are the 3 factors that affect a need for a transport system?
1. Size 2. Level of Activity 3. Surface area to volume ratio
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What is a single circulatory system?
Blood flows once around the body
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What is a double circulatory system?
Blood travels through heart twice per circuit - pulmonary circulation carries blood to lungs to pick up oxygen and systemic circulation carries oxygenated blood round the body
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What is an open circulatory sytem?
What insects have - blood flows freely through body cavity and oxygen diffuses into insects through spiracles which are attached to tracheoles which are ventilated by contraction of muscles
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What is a closed circulatory system?
Mammals have these - blood closed at all times within vessels and blood is pumped within vessels
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What is the structure and function of arteries?
Carries blood away from heart to other parts of body - arteries keep & withstand pressure as they have a small lumen, thick and strong walls made from elastic fibre and muscle for strength & recoil and swell & contract
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What is the structure and function of veins?
Brings blood back to heart - thin outer wall, large lumen, valves to prevent backflow and strong walls (thinner than artery walls)
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What is the structure and function of capillaries?
Link between arteries and veins, diffusion into/out of blood only occurs here - outer wall only one cell thin allowing diffusion of substances, small lumen and very thin to fit in between cells to bring blood to all cells in the body
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How is tissue fluid formed?
1. Blood in arteriolar end has high hydrostatic pressure (high wp) 2. Due to high wp, all dissolved ions and water are forced out capillary lining (ultrafiltration) 3. At venous end blood has low hydrostatic pressure & high oncotic pressure due to
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big protein build up 4. Water is drawed back into capillaries via osmosis
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Describe the cardiac cycle
1. SAN sends signal across walls of both atria 2. Signal causes atria to contract 3. Signal reaches AVN and there is a delay 4. Signal conducted down purkyne fibres 5. Signal causes ventricles to contract from apex upwards
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What happens during diastole?
Atria & ventricles relaxed, pressure decreased, internal volume decreases, blood flows into heart from major veins, blood flows into atria, then through open atrioventricular valves and into ventricles
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What happens during atrial systole?
Both atria contract together, small increase in pressure due to contraction pushes blood from aorta into ventricles, stretches walls of ventricles filling them with blood, AV valves then shut
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What happens during ventricular systole?
Ventricles full of blood, begin to contract, pressure increases, volume decreases, contractions start at apex pushing blood upwards, semilunar valves forced open, blood pushed into arteries, semilunar valves shut
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What are ECGs used by doctors for?
1. Assess heart rhythm 2. Diagnose cardiac arrhythmia 3. Diagnose heart attacks 4. Identify abnormalities
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Draw an ECG reading and label the waves
Diagram in folder
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What are the 4 different types of heart beat?
1. Tachycardia - abnormally fast heart rate 2. Bradycardia - abnormally slow heart rate 3. Fibrillation - irregular heart beat & fibrillation between QRS complexes 4. Ectopic heartbeat - extra heartbeat where only atria or ventricles contract
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Why does haemoglobin have a higher affinity to carbon dioxide than oxygen?
Hb dissociates with oxygen and binds to carbon dioxide when area of low PO2, this deposits oxygen where it is needed and gets rid of carbon dioxide
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What is the Bohr Effect?
First oxygen molecule binds to haem group and this changes the overall shape of Hb making it easier for the other 3 molecules to bind
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Describe the bicarbonate buffer system
1. CO2 in plasma diffuses into blood 2. Reacts with water by enzyme carbonic anhydrase -> carbonic acid 3. Dissociates into H+ ions & bicarbonate ions 4. Bicarb ions diffuses out cell initating Cl- shift 5. H+ ions causes dissocation oxygen from Hb
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Why do plants need a transport system?
1. Move water and minerals from the roots up to the leaves 2. Move sugars from the leaves to the root of the plant
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Draw a diagram of the xylem & phloem in the root
In bio book
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Draw a diagram of the xylem & phloem in the stem
In bio book
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Draw a diagram of the xylem & phloem in the leaf
In bio book
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Describe the structure of the xylem
1. Parenchyma cells as packing tissue for support 2. Lignin impregnates cells and kills them making them waterproof 3. Lignin also strengthens cell walls and prevents cell collapse 4. Incomplete lignification = bordered pits = entry in other vessels
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What are the adaptations of the xylem?
1. Made of dead cells alligned end to end to form a continuous column 2. Narrow tubes so water column does not break 3. Bordered pits to allow water to move from each vessel 4. Lignin diposits in cell walls allows xylem to stretch as plant grows/bend
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Why is the flow of water not impacted in the xylem?
1. There are no cross walls 2. No cell contents, nucleus or cytoplasm 3. Lignin thickening prevents collapse of cell
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Describe the structure of the phloem
Sieve tube elements that are lined up, contains no nucleus and little cytoplasm, companion cells linked to sieve tubes with many mitochondria in and large nucleus & dense cytoplasm for translocation
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What are the different pathways of water through plants?
1. Apopolast way - by mass flow through spaces between cells in cell walls 2. Symplast way - enters cell through plasma membrane and passes through plasmodesmata from each cell to next 3. Vacuolar way - Like symplast, but travels through vacuoles
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Define transpiration
The loss of water vapour from the aerial parts of the plants, mostly through the stomata in the leaves
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What is the importance of the transpiration stream?
1. Transports useful minerals ions up the plant 2. Maintains cell turgidity 3. Supplies water for growth, cell elongation and photosynthesis 4. Supplies water that as evaporates can keep plant cool on a hot day
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What are the 5 environmental factors that affect the transpiration rate?
1. Light intensity higher = higher TR as stomata open 2. Temperature high = higher TR (rate of evaporation & KE of molecules) 3. Relative humidity higher = lower TR 4. Air movement (wind) higher = higher TP 5. Water availability - higher = higher TR
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What is a potometer?
A device that can measure the rate of water uptake as a leafy stem transpires
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What are the types of mass flow to move water up the stem?
1. Root pressure 2. Transpiration pull 3. Capillary action (adhesion is the attraction of water to the walls of xylem vessel due to narrow walls)
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What are xerophytes?
A plant adapted to living in dry conditions
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What are hydrophytes?
A plant adapted to living in water or where the ground is very wet
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How is marram grass adapted to reduce water loss?
Xerophyte - leaf coiled longtitudinally to trap air inside making humid, thick waxy cuticle, stomata on inner side of leaf, stomata in pits on lower epidermis which is folded & covered by hairs, dense spongy mesophyll so less SA for evaporation
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How are cacti adapted to reduce water loss?
Xerophyte - succulants that store water, stem is ribbed/fluted to expand when water available, spikes instead of leaves, stem is green for photosynthesis, widespread roots
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How is the water lily adapted to live in water?
Hydrophyte - many large air spaces on leaf keeping leaves afloat to absorb sunlight, stomata on upper epidermis to allow gaseous exchange, leaf stem has many large air spaces for buoyancy & allows oxygen to diffuse quickly into roots
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Describe the process of translocation
1. H+ ions pumped out by active transport from companon cell 2. H+ conc gradient created outside 3. H+ ions with sucrose molecules diffuse back in via cotransport proteins 4. Increased conc of sucrose causes diffusion in sieve tubes by plasmodesmata
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How is sucrose moved around the sieve tubes?
1. Increased sucrose lowers water potential 2. Water flows in by osmosis increasing hs pres 3. Sap moves down tube from high hydrostatic pressure from source to low hs pres at sink 4. Sucrose removed and used up increasing wp 5. Water moves out
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Explain how fish breath gas in
Fish opens mouth (buccal cavity), floor of mouth moves down, volume inside buccal cavity increases & pressure decreases, water flows in, operculum is closed
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Explain how fish breath gas out
Fish closes mouth, floor of the buccal cavity is moved upwards, decreasing the volume and increasing the pressure, water is pushed through the gills, operculum is open reducing the pressure in the opercular cavity helping water to flow through gills
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How do insects inhale
Abdonimal muscles contract & flatten in the body, volume of the tracheal system decreases, air pressure inside trachea increased, air is forced out though spiracles
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How do insects exhale
Abdominal muscles relax & body returns to original shape, spiracles open, air pressure inside trachea lowered, air drawn in
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Other cards in this set

Card 2


How does air get from the airways to the alveoli?


Airways -> Lungs -> Trachea -> Bronchi -> Bronchioles -> Alveoli

Card 3


What is cartilage used for?


Preview of the front of card 3

Card 4


What are cilia used for?


Preview of the front of card 4

Card 5


What are goblet cells used for?


Preview of the front of card 5
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