Transport in Animals, Plants, Insects (3) Flashcards

Question

label the diagram with *tidal volume, vital capacity, total lung capacity, inspiratory reserve volume, expiratory reserve volume, residual volume, breathing rate*

Answer 1

spiracles, tracheae, branching of tracheae, tracheoles tracheal fluid, respiring cells

Answer 2

nasal cavity, larynx, trachea, bronchiole, bronchus, pleural membranes, pleural cavity containing pleural fluid so that membranes slide over each other as we breathe, abdominal cavity, diaphragm, position of the heart, rib, intercostal muscles

Answer 3

SIZE SA:VOL METABOLIC ACTIVITY

Answer 4

LEFT-ATRIO VENTRICULAR VALVE **prevents back flow** of blood from LV to LA during **ventricular systole**

Answer 5

**provide a very large SA for exchange** of substances between the tissues and blood **total cross-sectional area** of the capillaries is _always greater_ than the **arteriole supplying them**, so rate of blood flow falls. relatively **slow** movement of blood through capillaries = more **time** for exchange by diffusion walls are **one endothelial cell thick**, giving a thin layer for diffusion/short diffusion distance

Answer 6

**_SINGLE_ circulation** **_DOUBLE_ circulation**

Answer 7

* COHESION TENSION* * ADHESION- CAPILLARITY* * ROOT PRESSURE*

Answer 8

takes **oxygenated** blood from the **left ventricle** to the **body**

Answer 9

a sequence of events of a **heart beat** which **pumps blood round the body** it has **alternate contractions**; **systole** and **relaxations**; **diastole** these events occur **simultaneously** in the RHS and LHS *approx. 0.8 secs, tf approx. 80 BPM*

Answer 10

THE BUFFERING OF PROTONS * the protons are *buffered by haemoglobin* to prevent a *change in pH of the RBCs.* This forms **haemoglobinic acid** * the binding of protons changes the *tertiary structure* of the Hb, _lowering its affinity for oxygen_ (*allosteric effect*) * *O₂*is able to *dissociate more easily* i.e. more will dissociate in the tissues.

Answer 11

**arrhythmia: abnormal irregular rhythm** from atria, ventricles lose regular rhythm rapid electrical impulses are generated in the atria, they contract very fast/fibrillate but not properly: only some of the impulses are passed onto the ventricles *ventricular fibrillation = less blood supplied to tissues because no time to re-fill aria- ventricles contracting all the time*

Answer 12

semi-lunar valves in the veins prevent backflow and pooling of blood (gravity) when blood is flowing against gravity eg. in the legs blood flowing away from the heart pushes the valves closed, preventing it from flowing further away

Answer 13

* elastic fibres- allow **expansion** of vessel **lumen** to **withstand high pressure** from the heart. **Elastic recoil maintains** the high pressure + keeps smooth the blood flow.* * endothelium- **inner layer of cells** are **folded** to allow increase in **diameter** of **lumen***

Answer 14

the heart is **myogenic** i.e. its rhythmic contractions arise from **within the cardiac muscle tissue itself** (instead of **neurogenic** i.e. needing nervous impulses to contract) ## Footnote * the conduction system is an intrinsic regulatory system composed of specialised tissues; **1. SA node, 2. AV node, 3. Bundle of His, 4. Purkinje fibres*** * it is capable of generating and distributing the electrical impulses that stimulate cardiac muscle to contract*

Answer 15

A **transmembrane protein** (a **carrier** or **channel**) which transports **two substances** across the **membrane**.

Answer 16

CSM of spongy mesophyll cells (which is where air spaces are)

Answer 17

_-double circulatory systems *maintain high pressure* over *both gas exchange surfaces*- lungs and tissues_ It can *differentiate* the pressure, so the *LHS* of the heart pumps blood at *much higher pressure* to the *tissues* than the *RHS* to the *lungs*. Pressure to *pulmonary capillaires is much larger* than to *systemic* capillaries.

Answer 18

* As humidity of the **air surrounding** the plant **increases,** the **concentration of water molecules** in the air **increases**. * The **diffusion gradient** between the **inside** of the **leaf** and the **surrounding air** **_decreases_** and the transpiration **rate _decreases_**. * Eventually an equilibrium is reached and there is **no** water vapour **loss** from the leaf.

Answer 19

**Contraction starts** at the **sino-atrial node** (SA node, also known as the **pacemaker**) which is embedded in the **wall of the right atrium** close to the entry of the vena cava A **wave of electrical excitation** flows over **both atria**, causing them to **contract**

Answer 20

1. large SA 2. high/active blood supply 3. small diffusion distances/ thin 4. permeable 5. moist

Answer 21

SLOW heart rate **below 60bpm** evenly spaced (*can be due to high fitness levels causing the heart to beat slowly and efficiently*) may need an artificial pacemaker

Answer 22

**atrial systole** *electrical charge/depolarisation spreads over both atria from SA node, causing atrial muscleto contract*

Answer 23

Due to the **pull of transpiration** 1. Transpiration from the leaves/sub-stomatal air creates a water potential gradient with the cells in the leaf 2. The 'pull' causes the movement of water across the leaf by the 3 pathways: apoplast, symplast, vacuolar 3. The 'pull' from the water moving in the leaves causes the movement of water through the xylem by mass flow, due to the cohesion & adhesion tensions caused by H-bonds 4. The 'pull' of the water from the xylem causes the movement of water across the cell of the root by the 3 pathways: a, s, v. The casparian strip in the endoderm causes the apoplast to join the symplast. 5. Water moves by osmosis into the root hair cells from the soil. Water diffuses through cell walls into the apoplast pathway. Water potential is very high (approx. -10kPa) because the soil solution is a very dilute solution of ions

Answer 24

-PARENCHYMA in the middle -VASCULAR BUNDLES in a circle around the parenchyma (around edge in order to provide support and strength) -XYLEM on the inner side of the vascular bundle -PHLOEM on the outer side of the vascular bundle -CORTEX is the outer half of the stem -EPIDERMIS around the cortex

Answer 25

microscopic blood vessels that link veins and arteries, forming an extensive networkt rhoguh all the tissues of the body capillaries are 10µm in diameter **substances are exchanged through the capillary walls eg. O₂, between the tissue cells and the blood** blood enters capillaries in organs from arterioles and is oxygenated. When it leaves to the venuoles it has less oxygen and more carbon dioxide/deoxygenated.

Answer 26

**Spindle-shaped cells** with **large, bordered, hollow pits** on the sides that allow the **passage of water + minerals** sideways to the living parts of the stem. (lateral movement of water) The ends of the cells **overlap** so water moves up the stem.

Answer 27

1. diaphragm muscles **contract** the diaphragm **flattens/lowers** 2. the **external intercostal** muscles **contract**, the **internal intercostal** muscles **relax**, ribs and sternum move **upwards and outwards** 3. the volume of the thorax (and therefore lungs) is **increased** and the pressure in the lungs is **decreased below atmospheric pressure** 4. air flows in

Answer 28

A plant that lives ; **submerged in water** of on the **surface of water** or at the **edge of bodies of water** and *do not have to conserve water* eg. water lilies

Answer 29

1. mouth opens, floor of buccal cavity is lowered 2. buccal cavity expands, volume increases, pressure decreases, water drawn in 3. opercular valve is closed, operculum (covering of gills) is closed, cavity fills with water 4. operculum moves outwards while closed, which pulls water in from buccal cavity

Answer 30

in the _ciliated epithelium_ of **trachea**, **bronchi** and **larger bronchioles**

Answer 31

**delivers oxygenated** blood from the **lungs** to the **left atrium**

Answer 32

**delivers deoxygenated** blood from the trunk and limbs to the **right atrium**

Answer 33

1. permeable 2. large surface area 3. thin exchange surface 4. moist 5. steep conc. grad. between the blood and the alveolar air (maintained by: good blood supply + ventilation of the lungs)

Answer 34

1. mouth closes, floor of buccal cavity is raised 2. buccal cavity becomes smaller, volume decreases, pressure increases 3. opercular valve is open, operculum opens, water flows over gills and out of operculum 4. gas exchange occurs between water and blood flowing through gills

Answer 35

The TSA of the alveoli and the numerous surrounding capillaries ensures _rapid diffusion of a larger quantity of O₂ gas from alveolar air into the blood_ (and vice versa for _CO₂_) T: alveolar walls are made of **squamous epithelial** cells (*flat and thin*), capillary walls made of **endothelial** cells which are *flat and thin* (cap walls are *one cell thick*) Therefore the **distance between the air in the alveoli and the blood in the capillaries is small**. Thinner the surface, higher the rate of diffusion.

Answer 36

alveoli (flattened epithelium in smaller bronchioles)

Answer 37

rate of diffusion = area of diffusion surface x difference in concentration / thickness of surface over which diffusion takes place

Answer 38

* Ciliated epithelium in tracheae, bronchi and larger bronchioles* * flattened epithelium in smaller bronchioles* _squamous epithelium in alveoli_

Answer 39

plants are less metabolically active than animals & tf have a much slower transport system ( + gases are transported by diffusion) the transport sugar in plants is sucrose, which is less reactive than the transport sugar in animals, glucose

Answer 40

* *the **evaporation of water** from the **aerial** parts of the plant eg. leaves/stomata* the **rate** of transpiration can be measured by a **potometer**, and is affected by many **factors**

Answer 41

to *carry deoxygenated blood away from tissues* to the heart _(pulmonary vein and umbilical vein are oxygenated)_ *blood goes from very small venuoles to larger veins, veins do not have a pulse, the blood pressure is low and they have valves* _veins do not have to withstand high pressure but need a large capacity_ *skeletal muscle contraction aids blood flow in the veins*

Answer 42

1. formed from _blood plasma._ 2. does not contain _blood cells_ or _plasma proteins_ (they are dissolved in fluid but not in plasma) 3. **wp** plasma \< **wp** tissue fluid which creates an **oncotic pressure** that pulls **water back into the plasma** from tissue fluid

Answer 43

VENTRICULAR SYSTOLE; **ventricles contract** ATRIAL DIASTOLE; **atria** are **relaxed** * blood is pumped f**rom left ventricle to aorta** and from the r**ight ventricle to pulmonary artery**, semilunar valves are **open*** * force/pressure of contractions **closes atrio-ventricular valves** so that there is **no back flow***

Answer 44

SERENCHYMA CELLS; ***specialised parenchyma** (packing) tissues in leaves, stems, roots. **Air spaces** are formed by apoptosis. Useful for **buoyancy** + **easy transport of O₂** to **submerged tissues** or in **mud** where O₂ levels are low.* AIR SACS; *enable **leaves + flowers** to **float** on the water*

Answer 45

ciliated epithelium

Answer 46

so that _larger_ quantities of oxygen can diffuse into the blood and _larger_ quantities of CO₂ may diffuse out of the blood, due to the steep concentration gradient that is maintained

Answer 47

VENTRICULAR DIASTOLE; **ventricles relax** *Increased quantity of blood in aorta and pulmonary artery causes **high pressure** which **closes semilunar** valves* ATRIAL DIASTOLE; **atria** are **relaxed** *blood flows **from atria to ventricles passively** due to gravity + relaxed state of the ventricles* ***atrio-ventricular valves** are **pushed open***

Answer 48

**delivers deoxygenated** blood from **RHS** of the heart to the **lungs** via the **pulmonary artery**

Answer 49

* **Minerals are pumped into** the xylem at the **roots** by **active transport using ATP** * **lowering the water potential** of the xylem at the roots. * **Water diffuses in** because of the **water potential gradient: (root pressure)** * and facilitates the movement of water into the roots from the soil * In some plants, *root pressure forces liquid out* of the leaves through *pores* called *hydathodes: guttation*

Answer 50

a substance, *similar to detergent*, which **reduces** the **surface** **tension** of a **liquid** in which it is **dissolved**

Answer 51

* think COMPARTMENTS, PRESSURE, VALVES* 1. P_AT \> P_V atrial systole AV valves are open 2. P_V \> P_ATP_V \> P_Aorta ventricular systole, atrial diastole blood travels down pressure gradient, blood does not flow back due to semi-lunar valves + chordae tendineae 3. P_V\< P_AT P_V \< P_Aorta ventricular diastole semilunar valves shut

Answer 52

_double circulatory systems allow for *more rapid flow* over *both gas exchange surfaces*, which is important in mammals and birds (due to *higher metabolic rate*)_ in single circulatory systems, eg. fish, *blood is slowed* down by both sets of *capillaries*- in the *gills* and then in the *tissues*- fish are *ectotherms* and therefore have a *low metabolic rate*, so this low speed of flow is sufficient

Answer 53

TRACHEOLES, are... * minute tubes filled with fluid* * very elongated cells* * without chitin- therefore very permeable to gases* * in direct contact with every cell in the insect* Oxygen is not tranported in haemolymph/haemocoel **at rest, oxygen dissolves in the fluid and diffuses into the cell**

Answer 54

VENTILATION: **while swimming, mouth and operculum are open = continuous water flow over the gills.** While stationary, _inspiration and expiration._

Answer 55

it occurs in water, which has an O2 content of \<1% compared to 20% in air, slow oxygen diffusion rate. Fish must pass large volumes of water over their respiratory surfaces compared to volume of air in terrestrial organisms. Therefore it is necessary to have good ventilation and an efficient gas exchange system.

Answer 56

spiracles (a type of pore) line the abdomen and trunk at regular intervals, which it enters through.

Answer 57

1. AIRSACS ## Footnote in flying insects, thin expandable walls act as resevoirs of air to increase ventilation during flight *NOT pumps* 2. MOVEMENT OF WINGS changes the volume of the body cavity and hence the pressure in the trachea 3. SELECTIVE OPENING AND CLOSING SPIRACLES * INSPIRATION:* abdomen increases in volume, spiracles in thorax open, air enters system * EXPIRATION:* abdomen decreases in volume, spiracles in abdomen open, air leaves system reduce water loss

Answer 58

* In the _placenta_, the _partial pressure of O₂ is 8kPa_ compared to 13kPa in the lungs. * at this partial pressure, the mother's Hb will _dissociate_ from/unload oxygen foetal Hb has a much **higher affinity** for oxygen at **low partial pressures (kPa)** than the mother's affinity. Therefore at the same partial pressure, it's curve is to the left and above the mother's curve. Tf, at the placenta **maternal** Hb will **dissociate** from the oxygen whilst **foetal Hb will associate** with it. The foetus is producing **CO₂** from its **respiring** tissues, which will diffuse into the capillaries of the mother. Due to the **Bohr** effect, there is further dissociation of O₂.

Answer 59

STAGE 1: atrial systole STAGE 2: ventricular systole, atrial diastole *blood flowing out of ventricles* STAGE 3: ventricular diastole, atrial diastole *blood flowing into ventricles*

Answer 60

1. _PRESSURE_ 2. _SPEED OF FLOW_ 3. _NO MIXING OF OXYGENATED AND DEOXYGENATED BLOOD_

Answer 61

**Bulk flow of fluid**, due to **hydrostatic pressure** which is the **pressure exerted by a fluid at rest**

Answer 62

heart **aorta, arteries, (named artery), arterioles, smooth muscle, narrow lumen** blood plasma **capillary endothelium/walls**

Answer 63

_tracheal fluid_ moves into the tracheoles, _oxygen_ in the tracheoles _dissolves in the fluid_ and diffuses _into the cell_

Answer 64

extra heartbeats are out of the normal rhythm - altered rhythm eg. extra beat + long pause before next beat

Answer 65

**receives** the **oxygenated** blood from the **lungs** via the **pulmonary vein**

Answer 66

**rings of C-shaped cartilage** They provide _support_. It's _strong but flexible_ and therefore _prevents_ the tracheae and bronchi from _collapsing_ when _breathing in_ and **pressure decreases**.

Answer 67

1. **unidirectional flow** through **vessels** 2. **high** pressure of flow, **different** between lungs and tissues 3. **rapid** speed of flow 4. **complete separation** between 2 halves of heart (and oxy. and deoxy. blood)

Answer 68

it will have a high SA:Vol ratio The rate of diffusion may no longer be sufficient i.e. not enough gas exchange on just its outer surface

Answer 69

RIGHT ATRIO-VENTRICULAR VALVE **prevents back flow** of blood from RV to RA during **ventricular systole**

Answer 70

ATRIAL SYSTOLE; **atria contract** VENTRICULAR DIASTOLE; **ventricles** are **relaxed** *blood flows **into the ventricles from the atria**, atrio-ventricular valves are **open***

Answer 71

Dependent on the LOADING TENSION Hb has a **high affinity** for oxygen where the **partial pressure of O₂ (pO₂/KPa) is high** in the *lungs*. Hb has a **low affinity** for oxygen where the **partial pressure of O₂ (pO₂/KPa) is low** in the *tissues.*

Answer 72

method of movement: **water potential gradient** 1. _Cytoplasm of one cell_ loses water to the _sub-stomatal airspace_ 2. This _lowers_ the _water potential (U)_ 3. The cell _pulls in_ more water from its neighbour, whose water potential is _higher_ 4. The water potential of this cell becomes _lower_ 5. (3+4 are repeated) This establishes a _water potential gradient._

Answer 73

FAST heartbeat- **over 100bpm**, evenly spaced (can be due to exercise, fever, fear, anger)

Answer 74

COLLAGEN ELASTIC FIBRES SMOOTH MUSCLE ENDOTHELIUM

Answer 75

*(BETWEEN P AND QRS: delay at AV node prevents overlap of atrial+ventricular systole)* **ventricular systole: electrical charge/depolarisation spreads upwards** over ventricles from the **apex**

Answer 76

**delivers deoxygenated** blood from the head and neck to the **right atrium**

Answer 77

**Dead cells lined end to end** whose horizontal walls have been broken down; water can travel in a **continuous column** * **Lined with rings/spirals of lignin**, which keep the vessels **open**, especially when the **transpiration pull exerts negative pressure** on the walls. * Lignin can also contain **tannins**, which are **bitter** and **deter herbivores.**

Answer 78

After being released by respiring tissues, it is carried in 3 ways: 1. **5% dissolved in plasma** 2. **10% carried by haemoglobin, forming carbaminohaemoglobin** 3. **85% combines with H₂O to form carbonic acid by the enzyme carbonic anhydrase in the RBCs. Carbonic acid dissociates to form hydrogen carbonate ions (HCO₃^-) and H⁺ protons.** CO₂ + H₂O ⇔ H₂CO₃⇔ HCO₃^- + H⁺ *carbonic anhydrase (CO2 + H2O)*

Answer 79

as length increases, SA increase, Vol increases Ratio decreases because volume increases relatively more than SA

Answer 80

in the tracheae, bronchi and bronchioles

Answer 81

_double circulatory system has *2 completely separate* parts. Therefore *efficiency of oxygen distribution is higher.*_ Important for mammals and birds which have a *higher metabolic rate* (amphibian+reptile allow mixing of blood in the heart before it is pumped out)

Answer 82

the **rate** at which an organism uses up oxygen eg. *_number of dm³ used_* per minute (dm³/min^-1)

Answer 83

* **Increasing temperature increases** the **kinetic energy** of all molecules. * Tf an increase in temperature will **increase** the transpiration **rate**, assuming the concentration of water molecules in the air is lower than in the leaf. * **Very high** temperatures will cause the **stomata to close**, which will cause the rate of transpiration to **reduce**.

Answer 84

the pressure **exerted** by the **fluid at rest** eg. water

Answer 85

Is it maintained by **ventilation of the lungs** Inhalation delivers _high concentration of O2_ into the airsacs so maintaining its _concentration high in the lungs_. Exhalation removes _carbon dioxide from the airsacs_ so maintaining its _concentration low in the lungs._ and **good blood supply through the numerous capillaries around the alveoli.** The _blood delivers a high concentration of CO2_ from respiring tissues to the _capillaries_ in the lungs. The _blood moves O2 away from the lungs_ by its constant flow, tf _maintaining a low concentration in the capillaries_. O2 diffuses from the alveoli to the blood and vice versa for CO2. Greater the conc, higher the rate of diffusion.

Answer 86

MOVEMENT of WATER VAPOUR in the SUB-STOMATAL AIRSPACE 1. **Water potential of atmosphere** is **lower \< Water potential** of the **sub-stomatal airspace** 2. Tf **if the stomata are open**, **water diffuses out** of the **stomatal pores** 3. *_Water potential*_ of the _*sub-stomatal air space*_ is _*lower \< Water potential*_ of the _*cell walls*_ of the _*spongy mesophyll_* cells 4. Water *_diffuses into*_ the _*sub-stomatal air space*_ _*down the water potential gradient*_ from the _*surrounding mesophyll_* cells

Answer 87

how many breaths are taken, usually per minute

Answer 88

TRACHEA, they... ## Footnote * carry **air into** the body* * are lined with **spirals of chitin** which keeps them **open when bent** or pressed (like cartilage in mammals)* * are **impermeable to O₂, CO₂***

Answer 89

between 60 and 100 bpm, evenly spaced

Answer 90

aerobic respiration is _not sufficient for oxygen demands_, _anaerobic_ respiration produces _lactic acid_, which accumulates. _water potential of cell decreases_ and becomes _lower than_ the water potential of tracheole _tracheal fluid_ drains into the _respiring tissue_ from the tracheoles, _delivers dissolved oxygen_ tracheole becomes _air-filled_, which _increases diffusion of O2 into the cell_ from the _steeper concentration gradient_ from air in tracheole

Answer 91

**prevent atrio-ventricular valves inverting** and therefore prevents back flow of blood during **ventricular systole**

Answer 92

by simple diffusion over a respiratory surface

Answer 93

a **hydrostatic pressure** caused by a **difference** in the amounts of **solutes between solutions** that are separated by a semi-permeable **membrane** (*oncotic pressure is the part of the osmotic pressure produced by colloids i.e. proteins and large molecules)*

Answer 94

-MIDRIB OF LEAF, which is the main vein of the leaf. Smaller, more numerous branching veins spread through the leaf for transport and support -VASCULAR BUNDLE in middle of midrib of leaf helps to support the structure of leaf -PALISADE MESOPHYLL the main photosynthetic tissue, on flat parts of leaf -XYLEM nearer flat side -PHLOEM nearer the raised part of midrib of leaf

Answer 95

Specialised tissues absorb required raw materials from the environment + transport materials and nutrients to all parts of the plants. 1. **water**; diffuses by osmosis through the root hair cells & apoplast pathway + transported to the rest of the plant by the xylem 2. **minerals**; taken up by active transport by the root hair cells + transported to the rest of the plant by the xylem 3. **sucrose**; produced in the leaves or stored in the roots + transported/translocated to the rest of the plant by the phloem O₂ and CO₂ are not transported, but diffuse in and out of the plant via specialised exchange surfaces: root hair cells + spongy mesophyll.

Answer 96

**SA node ⇒ atria contract ⇒ AV node ⇒ bundle of His ⇒ Purkyne fibres ⇒ ventricles contract ⇒ diastole**

Answer 97

P: O₂ and CO₂ are **non-polar** and can diffuse across the phospholipid bilayer of cell membranes M: *water lines the airsacs* and is mixed with **lung surfactant**, which breaks the **surface tension** of water to allow the airsacs to **expand** during inhalation. This allows the gases to *dissolve and diffuse* across the walls.

Answer 98

* water moves through the **cytoplasm*** * cytoplasm of **adjacent** cells is connected by **plasmodesmata** (strands of cytoplasm)* * there is **resistance** to flow (due to organelles)- less water flows through this pathway than apoplast*

Answer 99

*blood pressure fluctuates in the heart due to contractions/pumping* the **arteries close** to the heart have a lot of **elastic tissue**, which allows the **walls to stretch** when blood **leaves** the heart. as blood moves out of the **aorta**, the pressure in the aorta begins to **decrease** the **elastic recoil** of the walls helps to **maintain blood pressure** in the aorta the further the blood moves along the arteries, the more the pressure decreases because there is an **increase in the total cross sectional area of the arteries** (and fewer fluctuations) *It is important to maintain a pressure gradient between the aorta and arterioles, so that blood keeps flowing towards the tissues*

Answer 100

1. *to **drain excess** fluid* 2. *to take up **cell debris** + **large** particles* 3. *to combat bacteria using **white cells*** 4. *to take up **fatty products of digestion** from small intestine*

Answer 101

1. many filaments with numerous lamellae (+numerous capillaries) **increases surface area** (**+high blood supply**) 2. thin wall- one layer of squamous epithelial cells **short diffusion distance** 3. rich blood supply from many capillaries **increases concentration gradient of gases and maintains it. countercurrent mechanism also maintains steep concentration gradient** 4. tips of gill filaments overlap **increasing resistance to water flow increases time for gas exchange as flow is slowed** 5. countercurrent system **blood flows in opposite direction to water flow. Approx. 80% water extracted bc concentration gradient is maintained and diffusion takes place all along the capillary**

Answer 102

As water molecules **move up the xylem**, they **attract neighbouring molecules** by **cohesion tension** due to **intermolecular hydrogen bonds** between the **polar water molecules**- pull water up 100m in giant redwood + sequioa trees. (water lost from the mesophyll cells in the leaves is replaced by water in the xylem due to the water potential gradient between the cells)

Answer 103

a mainly _non-living vascular tissue_ composed of **_vessel elements_** (*elongated, hollow, dead cells*) and **_tracheides_** packed _between parenchyma cells_

Answer 104

SIZE : large plants have a _small SA:Vol_ therefore, _diffusion is too slow_ for the _movement_ of substances eg. sucrose/water, throughout the plant/to respiring or photosynthesising cells. Tf transport system/bulk transport necessary. ## Footnote CO₂ + O₂: *required for photosynthesis + respiration, rely entirely on diffusion (however, specialised exchange surfaces exist in the tissues concerned)*

Answer 105

tracheoles

Answer 106

* *Through the **cellulose cell walls.** Path of **least resistance** (no organelles/cellular structure impeding). 90% of water travels via this pathway* * **Cellulose fibres** of the cell wall have **channels** between them where water can flow freely by **cohesion tension**. * As water **evaporates** into the **sub-stomatal airspace** from one cell, **cohesive forces** between water molecules due to their **hydrogen bonds pulls water** from spaces in the walls of adjacent cells.

Answer 107

a **plant tissue** that **transports nutrients and water** through the organism (comparable to veins and arteries in animals). *Two types: xylem and phloem*

Answer 108

_PULMONARY CIRCULATION:_ **RHS** of heart pumps **deoxygenated** blood to the **lungs** via the **pulmonary artery**. Oxygenated blood then enters the LHS from the **pulmonary vein**. _SYSTEMIC CIRCULATION:_ LHS of the heart pumps the blood to the **tissues** via the **aorta**. **Deoxygenated** blood enter the RHS via the **vena cava**.

Answer 109

in the trachea, bronchi (and largest of bronchioles)

Answer 110

**receives deoxygenated** from the **body** via the **vena cava**

Answer 111

an **exoskeleton** of **chitin** and a layer of **waxy** **cuticle** to **reduce water loss**. Therefore they are *impermeable to gases*

Answer 112

* length = cm (100)* * surface area = cm² (10,000)* * volume = cm³ (1,000,000)* **Sa:Vol = cm²/cm³ ratio (cm^-1)**

Answer 113

Only 90% of tissue fluid re-enters the blood. *10% containing cell debris & excess fluid enters the lymph capillaries of the lymphatic system as lymph* Lymph moves away from the blind ends of the lymph capillaries and drains back into the blood/circulatory system via the large veins the the neck.

Answer 114

the **dry (organic) mass of living organisms**, usually measured at a trophic level e.g. producers in a food chain

Answer 115

*Lined with CILIATED COLUMNAR EPITHELIUM, interspersed with mucus-secreting goblet cells.* The goblet cells **secrete mucus**, which **traps microorganisms** and **dust particles** in the **inhaled air**, **preventing entry** to the alveoli. The **cilia** on the **surface** of the epithelial cells **beat** the mucus. Cilia **move** mucus upwards, **away** from the alveoli, to the throat, where it is **swallowed.** This **prevents entry** to the alveoli and **prevents** subsequent lung **infection**.

Answer 116

The walls of the **vessel elements** are strengthened by **lignin spiralling in the lumen**, which is *waterproof* and provides *structural support* against the *pull of transpiration* (and therefore the *collapse* of vessel elements). The xylem vessels are surrounded by **thick-walled parenchyma**, which **store food** and **tannin** deposits (a *bitter* chemical that *prevents herbivores digesting* the plant).

Answer 117

*mass flow =* the movement of a **fluid in bulk** in **one direction** A **heart** **pumps blood**, moving it **quickly** to **all parts** of the body.

Answer 118

atria contract, blood goes from atria to ventricles ventricles contract, atrio-ventricular valves close semi-lunar valves open, blood goes from ventricle to aorta semi-lunar valve closes, ventricles have stopped contracting at beginning of diastole atrio-ventricular valve opens, blood goes from atria to ventricles atria fill with blood from veins, blood goes form atria to ventricles due to gravity

Answer 119

_At the *arterial* end_ * blood is under **high hydrostatic pressure** * **hydrostatic pressure of blood \> oncotic pressure of blood** * **net movement** = fluid/water moves from **blood plasma to tissue fluid** by **mass flow** _At the *venous* end_ * **hydrostatic pressure decreases** * **hydrostatic pressure of blood \< oncotic pressure of blood** * **net movement** = fluid/water moves from **tissue fluid back into capillary** by **osmosis**; 90% water diffuses into capillary * *_Dissolved_ substances leave capillary by _filtration and diffusion._ Glucose, amino acids, ions and oxygen move out of the capillary.* * *_Waste products_ diffuse _into_ the blood; eg. carbon dioxide.* * If diet is protein deficient, water does not diffuse into blood

Answer 120

takes **deoxygenated** blood from the **right ventricle** to the **lungs**

Answer 121

_IN THE WALLS surrounding the epithelium_ ***Elastic fibres-*** help the process of *breathing out*. -When the **lungs inflate** (breathing in), the elastic fibres are **stretched**. The **fibres recoil** to **push air out** (exhaling). ***Smooth muscle-*** allows the **diameter** of the airway to be **controlled**. -Smooth muscle **relaxes**, widening the tube, during *exercise*. This gives **less resistance** to **airflow**, allowing air to move in and out of the airways more *easily* for **increased delivery** of **oxygen/removal** of **carbon dioxide**.

Answer 122

**_SINGLE_** circulation blood passes through the heart **once** in **each circulation** eg. FISH, the heart pumps **deoxygenated** blood to the **gills** where gases are **exchanged**, **oxygenated** blood goes to the rest of the body/**tissues** from the gills **directly**, **deoxygenated** blood then **returns** to the heart

Answer 123

DAY: **cohesive tension forces** are higher during the day There is less tension in the xylem at night because the **rate of transpiration is low**. DENDROGRAPH

Answer 124

the same tissues as arteries but in smaller quantities. ## Footnote **collagen, elastic fibres, smooth muscle, endothelium + valves**

Answer 125

yes, because both oxygen and carbon dioxide are non-polar and the bilayer is very permeable to them

Answer 126

*Buccal cavity*- GILLS (a gill arch holds many **gill filaments**. On each filament there are many **lamellae**) Water passes over the lamellae to the *opercular cavity.*

Answer 127

1. **unidirectional flow** through **vessels** 2. pressure of flow is **higher** than **open**, but no differentiation between gills and tissues 3. speed of flow is **relatively rapid** 4. **oxygenated** blood flows directly to tissues **from gills**; no separation/mixing

Answer 128

the cells of the **phloem** that **allow movement of sap** up and down the plant, from the **source** to the **sink**

Answer 129

**prevent back flow** of blood from **aorta + pulmonary artery** during **ventricular diastole** due to the force of **gravity**

Answer 130

*_Hydrogen carbonate ions HCO₃_**^-* diffuse out of the RBCs. In order to balance the negative ions leaving, *_chloride ions Cl_**^-*enter the RBC. (in the tissues)

Answer 131

*Movement of water through the vacuoles- takes water from apoplast pathway, therefore less water follows this pathway.* Through the established **water potential gradient**, water in the vacuoles of cell 1 will cross: **Vacuole** of cell 1, **Tonoplast** of cell 1, **Cell membrane** of cell 1, **Cell wall** of cell 1, **Cell wall** of cell 2, **Cell membrane** of cell 2, **Tonoplast** of cell 2, **Vacuole** of cell 2 *Therefore individual cells can absorb water from the apoplast pathway. Method of movement: water potential gradient + osmosis.*

Answer 132

The presence of *increased CO₂ shifts* the _Hb-oxygen dissociation curve_ to the *right + down* ## Footnote *therefore,* at the **same partial pressure of O₂ (pO₂)** the *dissociation of O₂* from Hb *increases* and the % *saturation* of Hb with O₂ *decreases.* Therefore _more O₂ is made available for the respiring cells._

Answer 133

**delivers oxygenated** blood from **LHS** of the heart to the **body** via the **aorta**

Answer 134

when forcibly exhaling. i.e. contraction of " is only noticable during heavy breathing and exercise, coughing and sneezing when air is forced out. (this process is no longer passive)

Answer 135

lung alveoli

Answer 136

*A **non-conducting layer/septum** of **connective tissue** exists between atria/ventricles that **prevents conduction,** except for a second node: **atrio-ventricular node (AV node)** (there is a time delay here)* From here, impulses travel **down the bundle of His** along the **interventricular septum** and along specialised **Purkinje fibres**, that fan out and up from the **apex** of the **ventricles**. This causes them to **contract** from the apex upwards and **push the blood** **out** through the _aorta_ and _pulmonary artery_.

Answer 137

Water molecules are **attracted to the walls of the xylem vessels** due to **adhesive forces**. (*can create frictional drag*)

Answer 138

**transport of water and nutrients** throughout plants from the roots to the shoots and leaves **support**

Answer 139

NO LIGNIN _LOW_

Answer 140

Up to **4 molecules** of oxygen can be carried by **one molecule of haemoglobin** *deoxyhaemoglobin* **Hb + 4O₂ ⇔ HbO₈***oxyhaemoglobin* The first molecule binds with difficulty, to an allosteric site, changing the tertiary structure. Each molecule is loaded progressively more easily.

Answer 141

**INSPIRATION** is an energy-requiring process where air is drawn in, diaphragm flattens/lowers and volume of the lungs increases. **EXPIRATION** is a passive process where air is expelled from the thorax, the diaphragm becomes more dome-shaped and the volume of the lungs decreases.

Answer 142

the volume of air in each breath at rest- usually about 0.4 dm3

Answer 143

* *to move substances eg. O₂, carbon dioxide and digestive products around the body* * to allow movement of substances around the body by **mass flow** which is **more rapid** than diffusion alone * to allow **transport** of substances **from exchange surfaces** with **large surface areas** (eg. lungs) and the **alimentary canal** (the small intestine) to the **rest of the body** * for delivery: **waste products** are **removed** from the cells and **excreted**; **hormones** are delivered to **target cells**; **heat** is **redistributed** in endotherms

Answer 144

in the *walls* of the **trachea**, **bronchi**, **bronchioles** and **alveoli** (everywhere)

Transport in Animals, Plants, Insects (3) Flashcards

(172 cards)