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95 Cards in this Set
- Front
- Back
The curve is steepest in the region marked X on the graph. Explain how the steepness of thecurve in region X helps the tissues in a mammal function more efficiently. |
small drop of ppO2 (dont do this in exam) large amount of oxygen dissociates easily tissues can respire aerobically aerobic respiration more efficient than anaerobic (prevents lactic acid build up) |
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What is the advantage of an increasing partial pressure of carbon dioxide in a muscle? |
more oxygen released at same partial pressure of oxygen needed for aerobic respiration |
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Explain the importance of the position of the dissociation curve of fetal haemoglobin |
higher affinity of oxygen; absorbed from mother becomes fully saturated at low ppO2 |
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. Explain howthis curve indicates the worm’s adaptation to its environment. |
lives in environment where low ppO2 allows Hb to become fully saturated at lower ppO2 |
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Xylem vessel |
transports water/ mineral ions |
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sieve tube element |
Transport of organic molecules/SUCROSE/ amino acids/ products of photosynthesis not glucose |
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Companion cell |
Makes proteins/ ATP/ release energy not make/ produce energy |
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function of lignin? |
supports/ strengthens/ prevents xylem vessel from collapsing when water sucked along it adhesion of water molecules aids movement of water upwards |
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Movement of water |
Water is absorbed into the root mainly through the root hairs. Its movement through theapoplast is prevented by the Casperian strip in the endodermis. Movementthrough the symplast pathway is aided by the plasmodesmata. The water is pulledupwards by the transpiration pull and this is possible by large cohesive forces between the water molecules and adhesion forces between the watermolecules and the hydrophilic lining of the cells. |
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Give three other properties of respiratory surfacescommon to all organisms. |
short diffusion pathway large surface area permeable moist concentration gradient |
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respiratory surface in inseccts |
tracheole in contact with tissue |
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Advantages of using a tracheal system for gas exchange |
fast (oxygen 200,000 x faster than blood) oxygen supplied directly to tissue; no transport system required |
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Describe and explain the process of inspiration in a mammal. |
intercostal muscles contract ribs upwards and outwards diaphragm contracts/ flattens volume increases pressure decreases below atm pressure (air drawn in) |
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State the difficulties aquatic organisms face, compared to terrestrial organisms, inobtaining oxygen from water. |
water contains less oxygen than air diffusion rate slower dense/ viscous medium more difficult to pump |
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why is countercurrent flow more efficient |
concentration gradient maintained over entire distance travelled by water over gills |
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suggest two reasons why terrestrial animals rely on internal fertilisation |
increased chance of fertilisation gametes independent of water for movement fertilised egg can develop inside protective layer gametes dont dehydrate |
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advantages of sexual reproduction |
variation allows a development of a resistant stage in lifecycle seeds, spores, larvae allow dispersal |
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cons of sexual reproduction |
slow form of reproduction (needs two individuals) |
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Suggest three reasons why the flowering plants have been so successful in the colonisationof the land. |
life cycle rapid; food store in seed allows rapid growth of embryo; enables to survive long periods of time protection by resistant outer layer leaf fall, recycling of nutrients, link with animals, no need of water for fertilisation |
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describe theory of evolution as put foward by Charles Darwin |
Darwin recognised species evolved over time explain adaptive radiation evidence= similar morpholgically to common ancestor similar proteins so similar DNA fossil evidence |
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what is ventilation |
the process of moving the respiratory medium over the respiratory surface |
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What organelles are present in guard cells but not in the other epidermal cells ofa leaf |
chloroplasts |
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Explain the mechanism by which light causes the opening of stomatal pores. |
potassium ions pumped into guard cell by active transport starch to malate WP in guard cell decreases water moves in by osmosis down WP gradient turgor increases, as cells expand, they bend as inner walls thicker than outer |
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What environmental factor could account for the displacement of the curve fromA to B |
increased carbon dioxide |
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significance of Bohr shift |
oxygen dissociates more easily at lower ppO2 |
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why are llamas curve to left of human? |
at low partial pressures of oxygen Hb has greater affinity to oxygen able to absorb more oxygen from environment |
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how are homologous structures used as evidence for evolution |
suggest shared common ancestory |
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advantage of asexual reproduction |
colonise area quickly |
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internal fertilisation |
fusion of gametes with femal body using intromittent organ no reference to zygote |
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mode of nutrition |
herbivore carnivore |
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Describe how the stomach of P is adapted to its diet (ruminant) |
cud mixed with ceullulase secreting bacteria allows cud to be regurgitated and further chewing allows water to be re-absorbed rumen=1st chamber, hosts microorganisms some absorption of fatty acids |
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Suggest why certain areas of carnivores stomach are larger |
to provide room to store meat until killing of prey next time long time between feeding... |
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blood vessels in sub mucosa |
transport dissolved products of digestion to liver (via hypatic portal vein) |
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lymphatic vessels in sub mucosa |
transport lipids |
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nerves in s.m. |
coordinates muscular contraction for peristalsis control secretion |
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brunners glands |
secretion of enzyme |
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state best technique for working out the relationships between the descendants ofthe orignal finch |
comparing DNA (DNA hybridisation) cytochrome C not gel electrophoresis |
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In a similar diagram of a human gut these features would be intermediatebetween those shown. Give a reason for this |
humans omnivores |
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Suggest a reason for refection |
gives more time to absorb nutrients (eat poo) |
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Cows feed in a similar way to rabbits but do not show refection.Explain this difference. |
cows have four more stomachs food is regurgitated for chewing of cud additional stomachs for fermentation |
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Name three structural features of fish gills which make them efficient gaseous exchangeorgans |
large surface area thin permeable good blood supply |
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advantage of countercurrent flow |
concentration maintained along whole of gill plate blood saturation reaches higher level |
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Describe the function of the hydrogen ions produced in the red blood cell andexplain its importance in muscle tissue |
dissociate oxygen from oxyhaemoglobin needed for aerobic respiration by muscle |
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explain function of chloride shift |
to maintain electrical neutrality of rbc |
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Describe and explain the difference in the transpiration rate at 0800hrs compared with1600hrs |
increased rate of transpiration increased temperature/ other factor not light |
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what is meant by cohesion? |
strong attraction of water molecules exert on one another |
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what creates tension |
water evaporating through stomata at top of column are replaced from below and because of cohesion, this creates an upward force (tension) throughout the column |
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how is root pressure generated? |
active transport of ions into root xylem water drawn in by osmosis at foot of xylem osotic pressure |
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What is the role of the intercostal muscles in the thorax of a mammal? |
move ribs/enlarge thorax |
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Give two advantages to a mammal of having internal lungs |
reduce heat loss reduce water loss protection (by ribs) |
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where are villi present? |
duodenum ileum |
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where is the site of mechanical breakdown of food |
mouth stomach |
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what connects with the bile duct? |
duodenum |
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where do microorganisms secrete vitamins? |
large intestine |
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where does carbohydrate digestion tak eplace? |
mouth duodenum illeum |
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where are brunners glands found |
duodenum, secrete alkaline fluid |
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main region of water absorption |
large intestine |
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where does protein digestion begin |
stomach |
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visible features anthropods have in common |
exoskeleton jointed limbs segmented body |
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significance of myoglobing |
oxygen store high affinity to oxygen used when muscle is working very hard |
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how do parasties survive without a digestive system? |
absorption of host nutrients over parasites body |
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why do parasited produce large numbers of offspring |
high mortality |
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what is meant by term source |
region where photosynthate produced |
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sink? |
region where photosynthate used |
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importance of closure of spiracles |
prevents excessive water loss |
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explain lifcycle of parasite |
eggs eaten by pigs tapeworm eggs in muscle undercooked meat eaten, containing eggs |
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explain why cynaide prevents stomatal pores from opening |
cynaide is a respiratory inhibitor (stops ATP) prevents active transport of potassium ions into guard cell |
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stae and explain adapatations of hydrophytes |
large air spaces for buoyancy stomata on upper surface to allow gas exchange with air thin cuticle as little water vapour loss little xylem as surrounded by water air spaces in stems allow diffusion of gases |
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why does aortic pressure not reach 0 where as ventricle does |
aortic (semilunar) valve closes preventing backflow ventricle diastole |
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how does hydrolysis of lipds increase ph |
xreates fatty acids increase pH |
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main sites of digestion? |
mouth stomach small intestine |
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main sites of absorption? |
small intestine large intestine |
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explain why human digestion system is divided into specialised regions |
diffwewnt regions carry out differnt function (enzyme optima)... |
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parasite |
lives in or on another organism deriving benefit whilst causing harm to host |
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describe one theory that would explain how water moves up stem of leafy shoot |
water vapour lost from leaves by transpiration causes tension on water molecules cohesive forces between water molecules adhesive forces between water molecules and xylem vessels water molecules pulled up xylem vessel |
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explain full reasons for max and min pressure in left ventricle and aorta |
contraction of left ventricle causes a surge in blood pressure pressure drops when left ventricale relaxes pressure in aorta does not decrease to zero as of closing of aortic, semi lunar valves elastic recoil of arteries maintains blood pressure |
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role of lymph vessel |
remove excess tissue fluid |
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autotrophs |
Autotrophs use {(simple) inorganic molecules / carbon dioxide andwater} to synthesise {(complex) organic compounds / named organiccompound eg Plant / named Plant / Algae / Bacteria must be qualified bychemosynthetic; |
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saprobiants |
Saprobionts {secrete enzymes onto the food outside the body / feedby extracellular digestion} and absorb ( or e.q.) the (soluble)products (by diffusion); NOT ingestBacteria / Fungi / or named |
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vessels found on surface of heart? |
Coronary;Supplies oxygen / blood to the heart muscle / wall / tissue / cells ORcorrect function for vein; |
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valves replacement |
Valve {exposed to / works at} a higher pressure (in left ventricle)/{Right ventricle pumps blood at / valve A exposed to} lowerpressures (to lungs); |
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what would happen to flow of blood if valve is damaged? |
Blood leaks back (from ventricle) to atrium ) Breathlessness |
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how do fish overcome problem of water? |
Water is forced over the gill by {ventilation mechanisms / pressuredifferences / continuous swimming};Unidirectionally / one way flow;Countercurrent flow of blood and water / or description of;{Diffusion / concentration} gradient is maintained or description of;over the entire gill surface;High affinity Hb; |
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importance of epithelium? |
Microvilli:Increase SA for diffusion / uptake of molecule / digestion (ofmolecules);11Mitochondria:(Synthesis of) ATP for active transport; |
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explain how endodermis carries out its function of uptake of water and mineral ions into plant |
Waterproof / Casparian strip / band / suberin;Blocks the apoplast pathway;Selective uptake / Active uptake / transport of minerals (byendodermis cells);Into symplast pathway;Active transport of minerals into pericycle;Water follows by osmosis;Water and minerals move into xylem vessels; |
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Describe three properties that all respiratory surfaces must possess and explain whythey must have them. |
Thin – small diffusion distance;Accept small diffusion distance/ pathwayLarge surface area- (large contact with air) for diffusion/ gasexchange/ OWTTE;Moist- allow gases to dissolve/ gases go into solution (to crossmembrane); Not diffuse intoPermeable-to allow gases to pass through (the respiratorysurface);NOT blood supply |
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Give two reasons why gills do not function effectively on land. |
They dry out/ unable to remain moist/ lose water; 2They clump together (because of surface tension.)/ collapse/lie on top of each other; |
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State the function of(i) sieve tube cells [1](ii) companion cells. |
{Translocation/ movement/ transport/ carry NOT flow} of{products of photosynthesis/ sucrose/organic compounds/sugars/ amino acids}/ description of source to sink/translocation;1(NOT nutrients/ other named sugar/ named ions)(ii) Carry out {metabolism/respiration} /to supply (sieve cells) with{energy/ATP}/ contain mitochondria for {ATP/ active transport};NOT contain organelles that the sieve cells do not have/ notloading sieve cell |
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Describe two features of an amniote egg |
Fluid filled cavity (surrounded by a membrane);{Protective/ hard/ leathery} {shell/ outer covering/ coat};(embryo within) yolk sac/ food store/ yolk for nutrition/ owninternal nutrient supply; |
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The development of embryos takes place internally in mammals. List three ways inwhich this is an advantage over externally laid eggs. |
(the young are retained) for a {considerable/ longer} time in themother’s womb or uterus;(The embryo is) nourished there from {the mother’s bloodsupply /the placenta}/ {unlimited nutrients/ OWTTE};Protection – qualified;The young are {born in a relatively advanced state ofdevelopment/ well developed/ more advanced growth inwomb}; [Any 3]NOT parental care/ ref to number of offspring |
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Give an account of the sequence of events that takes place during the digestionand absorption of a meal containing carbohydrate and protein. |
n buccal cavity/ mouth;B teeth (and tongue) {mechanically/ physically} break down food/to provide large surface area;C (Saliva added from) salivary glands;D (saliva) contains mucus to lubricate;E Amylase substrate is starch, product is maltose/ disaccharides;F Stomach adapted for protein digestion/ protein digestion{starts/ begins} in stomach/ proteins are partially digested inthe stomach;G Produces hydrochloric acid/ low pH in stomach;H Peptidase/Pepsin’s substrate is {protein/ polypeptides},products are {polypeptides/peptides};reject ref to other enzymesI Small intestine (is adapted to) completes (protein/carbohydrate) digestion/ Description of {disaccharide/polpeptide} digestion in small intestine;J Named enzyme produced by small intestine;K Two named enzymes produced by pancreas;L correct reference to endo- exo- peptidases;M Absorption takes place in the ileum/small intestine;N Villi / microvilli increase surface area;O Glucose/ monosaccharides/ products are absorbed bydiffusion and active transport; |
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Name the original source of energy that moves water through a plant. |
sunlight |
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where is the main site of lipase production |
pancreas |
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Explain how the jaw and teeth shown above are adapted for this mode ofnutrition herbivore |
{large/ridged/WM shape} {molars/premolars} for grinding;{diastema/space with no teeth/ gap between teeth} toassist with {chewing/ (tongue to) manipulate food/ cud};{well developed/ sharp/ long} incisors for {biting/ cutting/slicing/ tearing} (vegetation);loose articulation/ jaw moves in a {horizontal/ circular}plane;3maxVery small/ no canines;open roots to allow continuous growth of molars; |
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Explain how the gut of this mammal is adapted for digestion. |
Four chambered stomach (NOT four stomachs) / rumen/large caecum;Contain cellulose digesting bacteria/ have cellulaseproducing bacteria; NOT cellulose eating bacteriaLong gut {to allow extra time for digestion of cellulose/cellulose harder to digest};Cud is regurgitated for further chewing; |