BIOLOGY MODULE 3 (papers 1 & 3) Flashcards

Question

what can be used to investigate breathing?

Answer 1

spirometer

Answer 2

- has oxygen-filled chamber with movable lid - person breathes through tube connected to oxygen chamber - when breathing, chamber moves up and down - movements recoded with pen attached to lid of chamber (spirometer trace) - soda lime in tube breathes into absorbs CO2

Answer 3

- decreases over time as air thats breathed out is a mixture of CO2 and O2 but CO2 is absorbed by soda lime - oxygen gets used up in respiration

Answer 4

- water enters fish's mouth and passes out through gills - gill plates have thin surface layer of cells to speed up diffusion - blood flows through gill plates in one direction and water flow in opposite direction (counter current) - conc of oxygen in water is always higher than in blood

Answer 5

- made of thin branches (gill filaments) so have a large SA for gas exchange - gill filaments are covered by many gill plated - each gill supported by a gill arch

Answer 6

- fish opens mouth, lowering floor of buccal cavity - volume of buccal cavity increases, decreasing pressure in cavity so water is sucked in - when fish closes mouth, floor of buccal cavity raises so volume inside cavity decreases, pressure increases so water is forced out across gill filaments - each gill's covered by a bony flap (operculum) to protect gill - increased pressure forces operculum on each side of head to open so water leaves gill

Answer 7

- place fish on dissection tray - push back operculum and use scissors to remove gills - cut each gill arch through bone at top and bottom - draw gill and label it

Answer 8

- air moves into tracheae through pores on insect surface (spiracles) - oxygen goes down conc gradient to cells, CO2 from cells moves down its own conc gradient to be released into atmosphere - tracheae branch off into smaller tracheoles & have thin, permeable walls - tracheoles also contain fluid that O2 dissolves in - O2 diffuses into body cells, CO2 diffuses in opposite direction

Answer 9

- fix insect to dissecting board - examine tracheae, then cut & remove exoskeleton from abdomen - use syringe to fill abdomen with saline solution to see tracheae (looks sliver) - can examine tracheae under light microscope with wet mount, should see rings of chitin in walls of tracheae

Answer 10

- single - closed - heart pumps deoxygenated blood to gills and then blood goes oxygenated from gills to rest of the body, then turns deoxygenated and goes back to heart

Answer 11

- double - closed - right side pumps doxygenated blood to lungs - from lungs blood goes oxygenated and travels back to the heart, then to the left side to rest of the body - from rest of the body it goes to the heart, when blood enter heart, it enters right side again

Answer 12

pulmonary system

Answer 13

systemic system

Answer 14

can give blood an extra push between the lungs and rest of the body - oxygen is delivered to tissues more quickly

Answer 15

- blood is enclosed within blood vessels - heart pumps blood to arteries which branch out into capillaries - substances diffuse from blood in capillaries into body cells but blood stays - veins take blood back to heart

Answer 16

- blood isnt enclosed in blood vessels all the time - heart is segmented so contracts in a wave starting from the back, pumping blood into single main artery - artery opens up into body cavity - blood flows around insects organs, makes its way back to heart through valves

Answer 17

supplies insects cells with nutrients

Answer 18

done by a system of tubes called tracheal system

Answer 19

- arteries - arterioles - capillaries - venules - veins

Answer 20

- arteries carry blood from the heart to the rest of the body - thick and muscular walls and have elastic tissue to stretch and recoil with heart beat to maintain high pressure - folded endothelium allows artery to expand - carried oxygenated blood to lungs (except pulmonary arteries)

Answer 21

- arteries branch into arterioles (smaller) - layer of smooth muscle but less elastic tissue - smooth muscle allows them to expand/contract to control blood flow to muscles

Answer 22

- branch from arterioles - smallest blood vessels - substances like glucose are exchanged between cells in capillaries so are adapted for efficient diffusion (walls are one cell thick)

Answer 23

- connected to capillaries - very thin walls that contain some muscle cells - join together to form veins

Answer 24

- take deoxygenated blood back to the heart at low pressure (except pulmonary veins - oxygenated) - wider lumen than arteries, little elastic or muscle tissue - have valves to stop backflow of blood against gravity - blood flow through veins is helped by body muscles

Answer 25

- fluid that surrounds cells in tissues - made from substances that leave blood plasma - no RBCs as they're too large to be pushed through capillary walls - cells take oxygen and nutrients from tissue fluid - substances move out capillaries to tissue fluid through pressure filtration

Answer 26

- artery end of capillary bed, hydrostatic pressure inside capillaries is larger than pressure in tissue fluid - pressure forces fluid out capillaries into spaces around cells to form tissue fluid - as fluid leaves, hydrostatic pressure in capillaries lowers so hydrostatic pressure at vein end is much lower - oncotic pressure is generated by plasma proteins - at venule end, WP is lower in capillaries than in tissue fluid due to fluid loss and high oncotic pressure - means some water re-enters capillaries from tissue fluid at venule end by osmosis

Answer 27

gets returned to blood through lymphatic system made of lymph vessels: - excess tissue fluid passes into lymph vessels, when inside its lymph - valves in lymph vessels stop lymph going backwards - lymph moves towards main lymph vessels in throax and returned to blood near the heart

Answer 28

- RBCs - WBCs - platelets - proteins - water - dissolved solutes

Answer 29

- no RBCs - very few WBCs - no platelets - very few proteins - water - dissolved solutes

Answer 30

- no RBCs - WBCs - no platelets - proteins (only antibodies) - water - dissolved solutes

Answer 31

- volume of blood pumped by the heart per minute (cm3 min-1) cardiac output = heart rate x stroke volume

Answer 32

it can contract and relax without receieving signals from nerves - controls the regular heart beat

Answer 33

- depolarisation spreads from SAN over atria - left & right atria contract and pump blood into ventricles - wave reaches AVN transmitted to bundle of His - wave transmittted along Purkyne fibres into ventricle - ventricles depolarise, pumping blood into arteries - atria and ventricles relax - when its relaxing, atria fill with blood from vena cava and pulmonary vein

Answer 34

carries wave of electrical activity into muscular walls of right and left ventricles, making them contract simultaneously

Answer 35

- pacemaker - sets rhythm of heartbeat by sending out regular waves of depolarisation to atrial walls

Answer 36

- records electrical activity of the heart - uses electrodes placed on the chest

Answer 37

heart beats too fast so isnt pumping blood efficiently

Answer 38

heart beats too slow

Answer 39

- irregular heartbeat - atria or ventricles lose their rhythm and stop contracting properly

Answer 40

- 'extra' heart beat - caused by early contraction of the atria than previous heartbeats - can be caused by early contraction of ventricles

Answer 41

- RBCs contain Hb - Hb has high affinity for oxygen (each molecule carries 4 oxygen) - in lungs, oxygen joins to iron to form oxyhaemoglobin - Hb + 4O2 ⇌ HbO8

Answer 42

partial pressure of oxygen (pO2) - oxygen loads onto Hb to for HbO8 = ↑ pO2 -HbO8 unlads its oxygen = ↓pO2

Answer 43

- is a measure of O2 conc. - ↑ conc of dissolved oxygen in cells = ↑ partial pressure - oxygen enters blood capillaries at alveoli (high pO2) in lungs - when cells respire they use up oxygen, lowering pO2 - RBCs deliver HbO8 to respiring tissues to unload oxygen - Hb goes back to lungs for more O2

Answer 44

- show how affinity for oxygen varies - it is a sigmoid curve and plateau’s when all haemoglobin is oxyghaemoglobin

Answer 45

further left = higher affinity

Answer 46

- Hb binds with first O2 molecule, its shape alters & makes it easier for other molecules to join - more saturated Hb makes it harder for O2 to join

Answer 47

fetus is better at absorbing oxygen from mothers blood - fetus gets oxygen from mothers blood across placenta - when mothers blood reaches placenta, oxygen saturation ↓ - fetus must have high affinity for O2 to get enough O2 to survive - is Hb had same affinity as adult Hb, its blood would be too unsaturated

Answer 48

- Hb gives up O2 more readily at partial pressures of CO2 - most CO2 from respiring tissues diffuses into RBCs & reacts with water and carbonic acid (catalysed by carbonic anhydrase) - carbonic acid dissociates to give H+ ions and hydrogencarbonate ions - increase in H+ ions makes HbO8 unload its O2 and forms haemoglobinic acid - hydrogencarbonate ions diffuse out RBCs and transported in blood plasma - chloride ions diffuse into RBCs (chloride shift) - when blood reaches lungs, low pCO2 causes some hydrogencarbonate and H+ ions to recombine with CO2 - CO2 then diffuses into alveoli

Answer 49

- chloride ions diffuse into RBCs to compensate for loss of hydrocarbonate ions - maintains balance of charge between RBCs and plasma

Answer 50

- transports water and mineral ions in solution - these substances move up the plant from roots to leaves - makes up vascular system

Answer 51

- transports sugars in solution both up and down the plant - makes up vascular system

Answer 52

xylem in centre surrounded by phloem to provide support for root as it pushes through the soil

Answer 53

xylem and phloem both near the outside to reduce bending

Answer 54

xylem and phloem make up a network of veins which support thin leaves

Answer 55

- long, thin tube-like structures formed on vessel elements - no end walls to make uninterrupted tube to allow water to pass though easily - cells are dead - no cytoplasm - walls are thickened by lignin for support (spirals or rings) - lignin increases with age - water and ions move in and out vessels through small pits where there is no lignin

Answer 56

- cells arranged in tubes - tissues contain phloem fibres, phloem parenchyma, sieve tube elements and companion cells

Answer 57

- living cells that form the tube for transporting solutes - joined end to end to form sieve tubes - sieve parts are at the end walls which have lots of holes to allow solutes to pass through - no nucleus, thin layer of cytoplasm and few organelles - cytoplasm of adjacent cells is connected through holes in sieve plates

Answer 58

- lack of nucleus and other organelles means sieve tube elements cant survive alone - companion cell for every sieve tube element - carry out living functions of themselves and sieve tube element

Answer 59

- use blade to cut cross-section of stem as thin as possible - use tweezers to place sections in water until use to stop them drying out - transfer sections to a dish containing stain - rinse off sections in water and mount onto slide

Answer 60

- through root hair cells and then root cortex (incl. endodermis) - water drawn into roots via osmosis (down WP gradient)

Answer 61

- water always moves from HIGH WP to LOW WP - soil in roots has high WP and leaves have lower WP (due to evaporation) - creates WP gradient that keeps moving through the plant, from roots to leaves

Answer 62

- water moves through the cytoplasm - cytoplasms of neighboring cells connect through plasmodesmata - water moves by osmosis

Answer 63

- water moves through cell walls - walls are very absorbent so water can diffuse through them - water also carries solutes and move from high hydrostatic pressure to low hydrostatic pressure (MASS FLOW)

Answer 64

- when water in apoplast pathway gets to endodermis cells in the root, its path is blocked by a waxy strip of cell walls (casparian strip) - means water has to go through symplast pathway and cell membrane - once past this barrier water moves into the xylem

Answer 65

- at the leaves water leaves xylem into cells through apoplast pathway - water evaporates from cell walls into spaces between cells in leaf - when stroma open, water diffuses out the leaf into surrounding air - loss of water from plants surface is TRANSPIRATION

Answer 66

- water evaporates from leaves and creates TENSION which pulls water into leaf - water is COHESIVE so when some are pulled more follow - water enters stem through root cortex - ADHESION is responsible for movement of water (water is attracted to walls of xylem so water rises up xylem)

Answer 67

- evaporation of water from a plants surface - happens as a result of gas exchange: 1. plant opens its stomata to let in CO2 to produce glucose (photosynthesis) 2. also lets water out - higher conc. of water inside than outside

Answer 68

- lighter = faster transpiration - stomata open when it gets light so CO2 can diffuse into leaf for photosynthesis

Answer 69

- higher temp = faster transpiration - warmer water molecules have more energy so evaporate from leaf faster - this increases WP gradient making water diffuse out leaf faster

Answer 70

- lower humidity = faster transpiration - if air is dry, WP gradient between air and leaf increases, increasing transpiration

Answer 71

- windier = faster transpiration - air movement blows water molecules from stomata - this increases WP gradient

Answer 72

1. cut shoot underwater at slant 2. assemble potometer in water & insert shoot underwater so no air enters 3. remove apparatus from water but keep capillary tube submerged in water beaker 4. check apparatus is water and air tight 5. dry leaves 6. remove end of capillary tube from beaker until one air bubble forms 7. record starting position of air bubble 8. use stopwatch to record distance of bubble moves per unit time (rate of movement = transpiration estimate)

Answer 73

- adapted to reduce water loss - live in dry habitats

Answer 74

- (marram grass) stomata in sunken pits to shelter from wind - (marram grass) hair on epidermis to trap moist air to reduce WP gradient between leaf and air - (marram grass) roll their leaves up in hot/windy conditions to trap moist air and reduced exposed SA - both have thick, waxy later on epidermis to reduce water loss by evaporation - (cacti) spines instead of leaves to reduce SA - (cacti) close stomata at hottest time of day

Answer 75

- live in aquatic habitats - dont need adaptations to reduce water loss - need adaptations to help cope with low oxygen levels

Answer 76

- air spaces in tissues help plants float and can act as a store for oxygen e.g. water lillies float on surface and absorb more light for photosynthesis - stomata only present on upper surface of floating leaves helps maximise gas exchange - have flexible leaves and stems, prevents damage by water currents, plants are supported by water

Answer 77

- movement of dissolves substances (assimilates) where theyre needed in a plant - is an energy requiring process that happens in phloem - moves substances from sources to sinks

Answer 78

where substance is made (high concentration there) - e.g. sucrose

Answer 79

where substance is used up (low concentration there) - e.g. other parts of the plant like food storage organs and meristems

Answer 80

by changing the dissolved substances at the sink (e.g. by breaking them down or making them into something else) - this makes sure there's always a lower conc at sink than source

Answer 81

1a. active transport is used to actively load solutes into sieve tubes of phloem at source 1b. this lowers WP inside sieve tubes so water enters tubes by osmosis from xylem and companion cells 1c. creates high pressure at source end of phloem 2a. at sink end, solutes are removed from phloem to be used 2b. this increases WP inside sieve tube to water leaves by osmosis 2c. lowers pressure in sieve tubes 3a. result = pressure gradient from source to sink 3b. gradient pushes solutes along sieve tubes to where they're needed

Answer 82

active loading

Answer 83

- used to move substances into companion cells from surrounding tissues and sieve tubes - concentration of sucrose is higher in companion cells than surrounding tissue cells - so sucrose is moved using ACTIVE TRANSPORT and CO-TRANSPORTER PROTEINS

Answer 84

- in companion cells ATP is used to actively transport H+ ions out the cell to surrounding tissue - sets up con. gradient (more H+ in tissue than companion cell) - H+ ion binds to co-transporter protein in companion cell membrane and re-enters cell - sucrose binds to co-transporter molecule at the same time so H+ moves sucrose into cell - sucrose molecules are transported out companion cells into sieve tubes

BIOLOGY MODULE 3 (papers 1 & 3) Flashcards

exchange and tranport, transport in animals, transport in plants (109 cards)