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1. haemoglobin Hb + 4O2 HbO8 Haemoglobin + oxygen oxyhaemoglobin 7 Partial pressure of oxygen (pO2) is a measure of ____________________________________. The greater the concentration of oxygen dissolved in cells, the higher the partial pressure. Oxygen loads onto haemoglobin when there is a ___________________. Oxygen unloads when _____________________. Found in: Made from: Each haem group can hold: Has a ‘high affinity’ for oxygen:
2. Oxygen dissociation 7 pO2 is high e.g. in the _________. Haemoglobin has a _________________ for oxygen So has a ___________________ of oxygen 100% saturation means: pO2 is low e.g. in the _________. Haemoglobin has a ________________for oxygen So has a ________________of oxygen The graph is ‘S’ shaped because:
3. 7 CO2 concentration on oxygen unloading Haemoglobin gives up oxygen more readily at higher partial pressure of _________. When a cell respires, it creates carbon dioxide which raises the pCO2 This increases the rate of oxygen unloading and the curve shifts _____________________ _____________________. This means the saturation of blood with oxygen in lower for a given pO2, meaning more oxygen is being released. This is called the Bohr effect
4. Haemoglobin in different organisms Animals that live in an oxygen depleted environment have haemoglobin with a ________ ______________ for oxygen than human haemoglobin. The dissociation curve is to the __________ of ours. e.g. Animals that are very active and have high oxygen demand have haemoglobin with a ________ ______________ for oxygen than human haemoglobin. The dissociation curve is to the __________ of ours. e.g.
5. Gaseous exchange 8 Surface area to volume ratio Features of specialised exchange surfaces Large _______________ to _______________ ratio Very _________________- to allow for ________________________________ ______________________________ to allow some substances to pass through movement of ______________________________- e.g. air movement of ______________________________- e.g. blood
6. Gaseous exchange 8 In insects Insects have rhythmical abdominal movements which__________________________ ________________________________ Air moves in through _______________ Oxygen diffuses down its ______________________________to the cells. CO2 moves _______________________ to the air. Features for gaseous exchange In fish Fish open and close their mouth which__________________________ ________________________________ Oxygen moves into blood through _______________ Oxygen diffuses down its ______________________________to the cells. Counter current: Features for gaseous exchange
7. Gaseous exchange 8 In Mammals Features for gaseous exchange In Single-celled organisms Features for gaseous exchange
8. Gaseous exchange 8 In Plants Features for gaseous exchange
9. Controlling water loss 8 In Insect Close ________________ during the hot part of the day ______________________ waxy cuticle Tiny hairs around the spiracles to ________________________ In plants Use of stomata: Xerophytes Stomata sunk in pits Curled leaves Hairs Waxy cuticle
10. 9 Circulatory System Double circulation: Blood supplied to the heart by:
11. 9 Circulatory System Arteries Carry blood: Lumen: Walls are thick and muscular: Folded endothelium: Veins Carry blood: Lumen: Walls have little elastic tissue/muscle: Valves: Capillaries Near cells in exchange tissues: One cell thick: Large number of capillaries: Networks in tissues called capillary beds
12. 9 Tissue fluid Tissue fluid is: It is made from: At the start of the capillary bed, near the _______________________ the hydrostatic pressure inside the capillaries is _________________________ than the hydrostatic pressure in the tissue fluid. This difference in pressure __________________________________________ ______________________ of the capillaries into the spaces around the cells. As fluid leaves, the pressure __________________ in the capillaries, so the pressure is ________________________ at the venous end of the capillaries. Due to the fluid loss, the ________________________________ is also lower at the venous end due to large proteins, so some water re-enters via ________________________. The remaining fluid drains via the _________________________ , and re-enters the blood supply near the heart.
13. 10 MOVEMENT OF WATER THROUGH PLANTS Osmosis is: Function of the root hair cells: To increase ____________ ___________ to speed up ________________________ Once absorbed, water moves into the ________________ and ______________ Until it reaches the xylem. Note- the root tip is the area for growth and is impermeable to water
14. 10 MOVEMENT OF WATER THROUGH PLANTS Symplast pathway- goes through the living part of the plant- the _____________. The ______________ are connected by ___________________. Apoplast pathway goes through the non-living parts of the root- the ___________ ___________. The walls are very absorbent and water can diffuse through them and the spaces in between. When water in the apoplast pathway reaches the _________________ Its path is blocked by the waxy layer called the ______________ __________. This forces all water into the __________ _______________ which means it has to travel through the __________________ which are partially-permeable and are semi-selective. The water then moves into the ________
15. MOVEMENT OF WATER THROUGH PLANTS 10 Cohesion tension is: Root pressure is:
16. MOVEMENT OF WATER THROUGH PLANTS 10 Transpiration Water evaporates from ______________________ And accumulates in _____________________. When the stomata open, water moves _____________________________________________________________________ Factors affective transpiration rate Temperature: Humidity: Wind speed: Light/Dark:
17. Reducing water loss 11 Xerophytes Reducing water loss Stomata- Leaf shape- Hairs- Waxy cuticle-
18. Unit 2: Chapter 14.1: Classification What is a species? How are species named? What are the two types of classification? How is classification related to evolution? Key words: ecological niche; gene pool; binomial system; generic name; classification; taxonomy; artificial; natural; kingdom; phylum; class; order; family; genus; species; phylogeny; How are the taxonomic groups organised? What do organisms in the same species have in common?
19. Unit 2: Chapter 14.1: Classification What is Phylogeny? What is a mule and why is it sterile? Name some difficulties with defining species: Mules can very occasionally produce fertile offspring – so are they a species?