Topic 3A: Exchange and Transport System

Question 1

Name something that essensial to cells

Answer 1

Oxygen

Question 2

Name 2 waste products that organisms excrete

Answer 2

carbon dioxide & urea

Question 3

What does an organisms SA:V ratio effect?

Answer 3

how quickly substances are exchanged

Question 4

Do larger or smaller organisms have a higher SA:V ratio?

Answer 4

smaller

Question 5

How do you work out volume (cm3)?

Answer 5

lxhxw

Question 6

How you work out surface area (cm2)?

Answer 6

hxwx how many faces

Question 7

How do you calculate volume of a cylinder?

Answer 7

pie r2 x h

Question 8

How do you calculate volume of a sphere?

Answer 8

4/3 pie r3

Question 9

Explain diffusion of single-celled organisms?

Answer 9

Diffuse directly in/out of the cell across the cell-surface membrane
Diffusion rate is fast due to the small distances substance must travel

Question 10

Do multicellular organisms diffuse across the membrane slowly and quickly?

Answer 10

Slowly

Question 11

Name 2 factors affecing the rate of diffusion

Answer 11

a thin exchange surface- alveolar epithelium only one cell think and a large exchange surface

Question 12

what 2 things does lung disease affect

Answer 12

ventilation and gas exchange

Question 13

what is tidal volume

Answer 13

the volume of air in each breath (between 0.4-0.5dm3)

Question 14

what is ventilation rate

Answer 14

number of breaths per min (15 breaths healthy)

Question 15

what is forced expiratory volume (FEV)

Answer 15

max volume of air that can be breathed out in one second

Question 16

what is forced vital capacity (FVC)

Answer 16

max volume of air its possible to breath forcefully out of the lungs after a really deep breath in

Question 17

what do lung diseases do to gas exchange

Answer 17

all reduce the rate of gas exchange in the alveoli, less oxygen is able to diffuse into the blood stream so body cells recieve less oxygen

Question 18

name and explain the 2 reasons why multicellular organisms diffuse across the outer membrane slowly

Answer 18

some cells are deep within the body, big distance between them and the outside environment
larger animals have low sa:v ratio difficult to exchange enough substances to supply increased volume of animal through small outer surface

Question 19

what do multicelular organisms need to absord/discrete substances

Answer 19

specialised exchange organs

Question 20

what does rate of heat loss from an organism depend on

Answer 20

surface area

Question 21

if an animal has a large volume what does this mean in relation to heat loss

Answer 21

small sa so harder to lose heat from its body

Question 22

because of the a small SA what does this mean for their metabolic rate (why)

Answer 22

low in large animals, high in small animals to generate enough energy to stay warm

Question 23

whats good about having a compact shape (animal)

Answer 23

animals with q compact shape have a small sa:v ratio, minimising heat loss from their surface

Question 24

what does an animals body shape depend on

Answer 24

temp of its environment

Question 25

do animas with a high sa:v ratio lose lots/little water

Answer 25

lose more water as it evapourates from their surface

Question 26

the trachea branch into what

Answer 26

tracheoles

Question 27

explain features of tracheoles

Answer 27

thin, permeable walls and go to indiviual cells

Question 28

what are tracheoles needed form

Answer 28

means that oxygen diffuses directly into the respiring cells the insects circulatory system doesn't transport o2 co2 from cells moves down its own conc gradient towards the spiracles released into the atmosphere

Question 29

name the structures used in breathing (IN ORDER)

Answer 29

tranchea - 2 bronchi - bronchus - bronchioles - alveoli - alveolus

Question 30

explain intercostal musces

Answer 30

found between the ribs, 3 layers of them (internal and external)

Question 31

what are the 2 processes that occur during ventilation

Answer 31

inspiration and expiration

Question 32

explain inspiration

Answer 32

external intercostal and diaphragm muscles contract, causing the ribcage to move upwards and outwards and the diaphram flattens, increasing the volume of the thoratic cavity increases lung pressure decreases below atmospheric pressure airflows low-high pressure active process

Question 33

explain expiration

Answer 33

external intercostal and diaphragm muscles relax, ribcage moves down and inwards diaphragm curves upwards again the volume of the thoratic cavity decreases, causing the air pressure gradient and out of the lungs passive process and can be forced

Question 34

what are capillaries surrounding

Answer 34

alveoli

Question 35

what are the walls of each alveolus made from

Answer 35

walls made from single layer of thin, flat cells called alveolar epithelium

Question 36

what are the walls of the capillaries made from

Answer 36

capillary endothelium

Question 37

whats the protein called in the walls of each alveolus

Answer 37

made from elastin

Question 38

explain gas exchange in the alveoli

Answer 38

o2 diffuses out of the alveoli, across the alveolar epithelium and the capillary endothelium and into Hb in the blood co2 diffuses into the alveoli from the blood

Question 39

why is losing more water when an animal with increased SA:V ratio and how do they compensate (living in hot conditions)

Answer 39

water evaporates quickly, some small desert mammals have kidney structure adaptations so they produce less urine to compensate

Question 40

what do small animals need to do to support their high metabolic rates

Answer 40

eat large amounts of high energy foods (seeds and nuts)

Question 41

what might small mammals have when the weather gets really cold

Answer 41

fur or hibernate

Question 42

what is created when gas exchange occurs over a gas exchange surface

Answer 42

a boundary between the outside environment and internal environment of an organism

Question 43

name the 2 most common things that increase rates of diffusion

Answer 43

large SA, thin (short diffusion pathway)

Question 44

explain gas exchange in single-celled organisms

Answer 44

absorb and release gases by diffusion through their membranes they have a high SA a thin surface and a short diffusion pathway

Question 45

where does gas surface exchange occur

Answer 45

gills

Question 46

what is the counter-current system

Answer 46

in the gills of a fish blood flows through the lamellae in one direction and water flows over them in the opposite dircetion

Question 47

what does the counter current system mean for the water/oxygen

Answer 47

Means that the water with a relatively high o2 con always flows next to the blood with low o2 conc meaning steep conc gradient is maintained

Question 48

where is the main gas exchange surface in plants

Answer 48

mesophyll cells

Question 49

how are mesophyll cells adapted for gas exchange

Answer 49

increased SA

Question 50

explain somata

Answer 50

gases move in and out through special pores in the epidermis called stomata they can open to allow gas exchange and close if the plant is lossing too much water guard cells control the opening and closing

Question 51

what are tracheae

Answer 51

microscopic air-filled pipes

Question 52

what are the pores on the tracheae called

Answer 52

spiracles

Question 53

explain the structure of the gills

Answer 53

water containing oxygen enters the fish through its mouth and pass out through the gills each gill is made of lots of thin plates called gill filaments, giving anlarge sa gill filaments are covered in lots of tiny structures called lamella, increases sa more lamella have lots of blood capillaries and thin surface layers of cells to speed up diffusion between h2o and blood