organisms exchange substances with their environment

Question 1

How does an increase in volume effect Surface Area:Volume ratio?

Answer 1

Larger volume means smaller SA:V ratio

Question 2

Name the process by which prokaryotes exchange gasses?

Answer 2

Diffusion, due to the small diffusion pathway

Question 3

Name three components of the tracheal system in insects?

Answer 3

Spiracles, Trachea, Tracheoles

Question 4

Name two components of the gas exchange system in gills of a fish?

Answer 4

Gill filaments, Lamellae

Question 5

By what principle do fish exchange gasses in their gills

Answer 5

Counter current mechanism

Question 6

Define dicotyledonous?

Answer 6

A plant in which the seed has two embryonic leaves

Question 7

Name two components of the leaves of dicotyledonous plants involved in gas exchange

Answer 7

Stomata, Guard Cells, mesophyll cells

Question 8

How do xerophytic plants limit water loss?

Answer 8

Waxy cuticle, hairy leaves, curled shape, sunken stomata, reduced SA: ration of leaves

Question 9

How do insects balance the need for gas exchange with the need to limit water loss

Answer 9

In dry conditions spiracles close to limit water loss

Question 10

Name three components of the lungs involved in gas exchange?

Answer 10

Trachea, Bronchioles, Alveoli

Question 11

Over which membranes in the lungs do gasses have to pass?

Answer 11

Alveolar epithelium, capillary epithelium

Question 12

What features of the surface over which gasses pass in the lungs have to enable efficient gas exchange?

Answer 12

Thin, flattened cells so short diffusion pathway

Question 13

Name the method of interaction between internal and external intercostal muscles

Answer 13

Antagonistic

Question 14

Outline the movement of the diaphragm muscle in a) inhalation and b) exhalation

Answer 14

a) the diaphragm muscle contracts, causing it to flatten, increasing volume of thorax
b) the diaphragm muscle relaxes, arching upwards, reducing the volume of the thorax

Question 15

What cavity is involved in gas exchange in the lungs?

Answer 15

Thorax/thoric Cavity

Question 16

State the equation for PVR (pulmonary ventilation rate)

Answer 16

PVR = Tidal Volume x Breathing Rate

Question 17

What builds up in the lungs as a result of cystic fibrosis?

Answer 17

Mucous

Question 18

What elements of lung function are affected by cystic fibrosis

Answer 18

The shorter diffusion pathway is made larger

Question 19

How do sufferers of fibrosis adjust to compensate for the change in their lung function

Answer 19

Increase ventilation (breathing) rate

Question 20

What forms in the lungs of TB sufferers

Answer 20

Scar tissue

Question 21

What disease does TB eventually lead to?

Answer 21

Cystic Fibrosis

Question 22

How does reducing the quantity of oxygen available affect the cells of the body

Answer 22

Reduces the rate of respiration

Question 23

What reaction occurs in which larger molecules are broken into smaller ones

Answer 23

hydrolysis

Question 24

Why must molecules be made smaller to allow digestion

Answer 24

To allow them to pass through cell membranes

Question 25

What two enzymes break down carbohydrates

Answer 25

Amylase and membrane-bound dissacharidases

Question 26

Which enzyme breaks down lipids

Answer 26

Lipases

Question 27

Explain how bile salts aid with the digestion of lipids

Answer 27

Bile salts emulsify lipids into micelles. This increases the SA for lipase to act upon

Question 28

Which three enzymes break down proteins

Answer 28

Endopepitdases, Exopeptidases, Depeptidases

Question 29

Briefly outline how the following enzymes carry out their function a) Endopeptidases b) Exopeptidases c) Dipeptidases

Answer 29

Endopeptidases attack anywhere along polypeptide chain, except ends. Exopeptidases attack ends of polypeptide chain. Dipeptidases break down dipeptides into single amino acids

Question 30

Where in mammals does absorption occur

Answer 30

Ileum

Question 31

What mechanism permits absorption of amino acids and monosaccharides

Answer 31

Co-transport

Question 32

State the equation for cardiac output (CO)

Answer 32

CO=heart rate x Stroke volume

Question 33

What is the role of Haemoglobin

Answer 33

To transport 02 around the body

Question 34

Do all organisms have the same type of haemoglobin

Answer 34

No

Question 35

What is haemoglobin made out of

Answer 35

3-4 Protein with the prosthetic group Fe

Question 36

Which metal ion is at the centre of the haemoglobin molecule

Answer 36

Fe

Question 37

In what cells is haemoglobin located

Answer 37

Red Blood cell

Question 38

How does one oxygen molecule binding to haemoglobin affect the binding of other molecules

Answer 38

It makes it easier

Question 39

Outline the Bohr effect

Answer 39

As ppCO2 increases, oxygen affinity decreases

Question 40

How do high altitude animals adapt to the low oxygen environment

Answer 40

They produce haemoglobin that has a higher affinity for oxygen

Question 41

What is the function of the kidneys

Answer 41

To filter the blood

Question 42

How do valves aid in heart function

Answer 42

Prevent back flow of blood and help maintain pressure

Question 43

What connects the valves to the walls of the heart

Answer 43

Chords (valve tendons)

Question 44

Describe the structure of the Arterioles and how it relates to the function

Answer 44

Thicker muscle than arteries. Able to control movement of blood into capillaries. Lower blood pressure than arteries so thinner elastic layer

Question 45

Describe the structure of the Veins and how it relates to the function

Answer 45

Thin muscle as not controlling blood flow to tissues. | Thin elastic as low blood pressure. thin wall as low blood pressure. Valves prevent backflow

Question 46

What feature of capillaries, relating to red blood cells, is important for their role as exchange surfaces

Answer 46

They are smaller. this pushes red blood cells right up against the capillary wall to shortest diffusion pathway

Question 47

Why is fluid forced out of the capillaries at the start of the capillary bed

Answer 47

Large hydrostatic pressure in capillary

Question 48

Were is hydrostatic press lower, the venue end or the arteriole end

Answer 48

Venule end

Question 49

How does the water potential of the blood change across the capillary bed

Answer 49

It gets lower

Question 50

What system is responsible for draining the excess fluid away from the tissues and back into the circulatory system

Answer 50

Lymphatic system

Question 51

What dead tissue in plants transports water

Answer 51

Xylem

Question 52

Outline the 4 steps fo the cohesion tension theory, starting at the leaves

Answer 52

1) Water evaporates from leaves 2) Tension created so water pulled into leaves from xylem 3) Cohesive water molecules pulled up xylem 4) Water enters xylem through roots

Question 53

Which living tissue transports organic substances

Answer 53

Phloem

Question 54

Does translocation require energy

Answer 54

yes

Question 55

Where do solutes move from and to in translocation

Answer 55

Source to Sink

Question 56

How do enzymes maintain a concentration gradient in translocation

Answer 56

They use up solutes at the sink, converting them to a different product to maintain a diffusion gradient

Question 57

What is the name of the best supported theory for how translocation occurs

Answer 57

Mass Flow

Question 58

How does ringing allow scientists to investigate transport in plants

Answer 58

Remove a ring of bark from a stem. Accumulation of sugars above the ring causes the bark to bulge, which indicates it is the phloem in the bark which is responsible for transporting sugars

Question 59

Name the blood vessels entering and leaving the heart?

Answer 59

Leaving - aorta — renal artery (left ventricle to kidneys) Leaving - Pulmonary artery (Right ventricle to lungs) Entering - Renal vein — Vena Cava (kidneys tho right atrium) Entering - Pulmonary vein (lungs to left atrium)