module 3

Question 1

name 4 substances and organism needs to exchange with its environment

Answer 1

oxygen, glucose, carbon dioxide and urea

Question 2

what is the relationship between surface area and volume ratio of an organism

Answer 2

smaller animals have a higher surface area: volume ratio

Question 3

what are the 4 specialised features of efficient gas exchange surfaces?

Answer 3

thin layers, large surface area, good blood supply and good ventilation

Question 4

what is the function of a goblet cell?

Answer 4

to secrete mucus to trap microorganisms and dust/ dirt

Question 5

what is the function of cilia

Answer 5

beat the mucus upward away from the alveoli towards the throat to prevent infections in the lungs

Question 6

what is the function of elastic fibres?

Answer 6

to help breathing out, the fibres recoil on breathing out and help push the air out

Question 7

what is smooth muscle for?

Answer 7

allows diameter of trachea, bronchi and bronchioles to be controlled

Question 8

what are the rings of cartilage for?

Answer 8

provide support to the trachea and bronchi to stop them collapsing when breathing in

Question 9

what is meant by tidal volume and vital capacity

Answer 9

volume of air in each breath and maximum volume of air that can be breathed in or out

Question 10

what’s the function of the gill plates and gill filaments in fish?

Answer 10

both of these feature increase the surface are a for exchange of gases

Question 11

what is the structure on an insects surface that allows air to enter the tracheae

Answer 11

spiracles

Question 12

3 reasons why multicellular organisms need a transport system

Answer 12

low surface area to volume ratio, higher metabolic rate, very active = large number of cells that are respiring very quickly

Question 13

why is the mammalian circulatory system described as double circulatory system

Answer 13

the blood passes through the heart twice

Question 14

what is an open circulatory system

Answer 14

blood isn’t enclosed in blood vessels all the time instead it flows through the body cavity freely

Question 15

is the blood pressure highest in veins or arteries

Answer 15

arteries

Question 16

what do the vales in the hart prevent?

Answer 16

the blood from flowing the wrong way

Question 17

what side of the heart pumps oxygenated blood around

Answer 17

right side

Question 18

what prevents the impulse from the atria travelling straight to the ventricles

Answer 18

a band of non conducting collagen

Question 19

what causes the QRS part of an ECG trace

Answer 19

the contraction of the ventricles

Question 20

how many oxygen molecules can haemoglobin carry

Answer 20

4

Question 21

what is carbon dioxide converted to in red blood cells

Answer 21

carbonic acid

Question 22

why doe multicellular plants need transport systems

Answer 22

need substances to be delivered and taken away

Question 23

what is the name of the substance that thickens the wall of the xylem vessels

Answer 23

lignin

Question 24

what is the function of companion cells

Answer 24

companion cells carry out the living functions for both themselves and their sieve cells

Question 25

why is transpiration a consequence of gaseous exchange?

Answer 25

a plant must open its stomata to let in CO2, but this also lets water out = higher conc. of water in the leaf than outside the leaf, so water moves out of the leaf and down the water potential gradient when the stomata is open

Question 26

what is used to measure transpiration

Answer 26

potometer

Question 27

what is a xerophyte

Answer 27

plants like cacti and marram grass hat are adapted to live in dry conditions

Question 28

what is a hydrophyte

Answer 28

plants like water lilies that are adapted to live in aquatic habitats

Question 29

in translocation what are sinks and sources?

Answer 29

sink- the area the substance is used up, source- the area where the substance is made up

Question 30

how do substances enter the phloem

Answer 30

active loading