transport in animals

Question 1

circulatory system of a fish

Answer 1

.single circulatory system

Question 2

closed circulatory system

Answer 2

.blood is enclosed by vessels

Question 3

differences between the closed circulatory system of the sea bass and the closed
circulatory system of a mammal.

Answer 3

.sea bass has a single circulatory and mammals have a double
.sea bas blood goes through heart once and mammals twice
.

Question 4

reasons why insects and other animals need well-developed transport systems.

Answer 4

.high metabolic demand
.need large amount of oxygen
.diffusion is not suffcient

Question 5

Explain why the surface area to volume ratio of an organism determines whether it needs a circulatory
system.

Answer 5

.larger organism = smaller SA:VOL
.means that rate of diffusion is too slow

Question 6

Compare and contrast the circulatory systems of mammals and fish.

Answer 6

similarites:
.both closed systems
.both have heart
.both carry oxygen using haemoglobin

differences:
.fish have single mammal has double circulatory system
.fish have one atrium and ventricle and mammal has two
.fish blood pressure is lower and mammals is higher

Question 7

compare the circulations of a frog and a mammal
and the relative effectiveness of each type of circulation.

Answer 7

circulations:
.both are double circulations
.blood in mammalian heart transported separately to lungs and body
.oxygenated and deoxy never mix
.blood from frog heart transported to lungs and body together
.oxy and deoxy do mix
.

effectiveness:
.both are effective
.but frog is less effective due to having less oxygen available for cells
.frogs heart beat faster to compensate

Question 8

how the structure of each type of blood vessel is adapted to its
function.

Answer 8

artery:
.carries blood away from heart under high pressure
.so has a thicker elastic layer to withstand the pressure and enables them to stretch and recoil
.collagen provides structual support

veins:
.carry blood back to heart
.under less pressure but needs to move against gravity
.thinner elastic layer
.has valves to prevent backflow
.more collagen to give structual support as they carry more blood

cappillaries:
.allows substances to be exchanged between blood and tissue fluid
.walls are one cell thick for short diffusion path
.only large enough for redblood cells to travel through in single file
.small enough to form network need to exchange substances

Question 9

how the difference in lumen size between arteries and veins is related to their
function.

Answer 9

.arteries = small lumen maintains pressure

.veins = large lumen cause low resistance needed cause of slow flow

.same flow rate is achieved by having a larger volume

Question 10

why the oncotic pressure of the blood depends only on the concentration of
large plasma proteins.

Answer 10

.they cannot pass through capillart walls but blood can
.imbalance of large plasma between blood and tissue fluid results in oncotic pressure

Question 11

A medical student concluded that a patient with kidney disease and a plasma albumin
concentration of 0.015 g dm–3 would show signs of swelling, such as swollen ankles.
Evaluate the student’s conclusion.

Answer 11

student is incorrect due to:
.kidney damage could lead to more loss in water
.single patient could respond atypically

student is correct because:
.net driving force is higher
.so more tissue fluid is formed

Question 12

similarities and differences between ultrafiltration and the formation of tissue fluid.

Answer 12

similarties:
.small molecules are filtered out of the blood
.both processes occur in capillaries
.high hydrostatic pressure in both

differences:
.filtrate enter Bowman’s capsule and then PCT in the kidney but tissue fluid bathes cells intercellular space
.molecules that are not reabsorbed by cap form urine in kidney but molecules that are not reabsorbed from tissue fluid will form lymph
.knot of capillaries in ultrafiltration but a
network of capillaries in formation of
tissue fluid

Question 13

roles of ions

Answer 13

NH4+ = production of nitrate ions by bacteria

H+ = loading of phloem

PO43- = DNA structure

Cl- = cofactor for amylase

Question 14

explain the movement of fluid in and out of a capillary.

Answer 14

.at arterial end hydrostatic is greater than oncotic pressure
.plasma moves out of cap

.at venous end hydrostatic is lower than oncotic pressure
.tissue fluid moves into cap

Question 15

two arteries that could be seen

Answer 15

.aorta
.pulmonary artery
.coronary artery

Question 16

order of heart

Answer 16

.SAN node
.right artium
.vena cava
.semilunar valve
.atrioventricular valve

Question 17

explain why people with VSD can easily become tired.

Answer 17

.blood leaks from left to right ventricle during ven systole
.more oxygenated blood delivered to lungs
.deoxy blood pass into left ventricle during atrial systole
.less oxy blood pumped around body

Question 18

stages of the cardiac cycle

Answer 18

.atrial diastole:
.atria and ventricles relax
.blood flows through AV valves
.blood enters atria

atrial systole:
.atria contract
.pressure in atria increases
.blood flows through AV valves
.more blood enters ventricles
.volume of ventricles increases
.pressure in ven increases
.pressure in ateries is low

ventricular systole:
.ventricles contract
.volume decreases
.pressure increase
.AV valves close
.semi-lunar valves open
.blood flows into aorta
.blood flows into pulmonary arteries

Question 19

Explain how the heart is controlling the electrical activity

Answer 19

.wave of excitation
.coming from AVN or SAN
.through atria or purkyne fibres
.causing contraction of ventricles

Question 20

Suggest why reduced heart rate is sometimes seen in people who are very aerobically fit.

Answer 20

.increased volume of ventricle
.increased , thickness
of heart muscle

Question 21

Human blood is maintained at a pH of 7.4 by reactions that occur in red blood cells.
Use your knowledge of these reactions to explain how a pH of 7.4 is maintained.

Answer 21

.of H+ reacts with haemoglobin to form haemoglobinic acid, which lowers pH
.H+ reacts with HCO3− to
form H2CO3, which lowers pH
.of H2CO3 dissociates to form
H+ and HCO3−, which raises pH

Question 22

Describe how the structure of llama hamoglobin is likely to be different from that
of camel haemoglobin with reference to the four levels of protein structure.

Answer 22

.diff in primary structure
.one amino acid changed
.causes change in secondary structure of the alpha helix or beta-pleated sheet
.amino acid could effect tertiary structure by futher coiling the secondary structure
.amino acid change has not affected the quaternary structure

Question 23

Explain why it is important for the survival of the llama that the llama haemoglobin
dissociation curve is to the left of the camel haemoglobin dissociation curve.

Answer 23

.haemoglobin needs higher
affinity for oxygen
.so can pick up oxygen at lower
partial pressure

Question 24

With reference to the structure of blood vessels, explain why oxygen is not
released until the blood reaches the capillaries.

Answer 24

.arteries have thick
wall
.diffusion distance (too) large for
artery

Question 25

What name is given to a change in the oxygen dissociation curve due to
increasing carbon dioxide concentration?

Answer 25

bohr shift

Question 26

Explain why the blood off-loads more oxygen to actively respiring tissues than
to resting tissues.

Answer 26

.more CO2 is produced
.so theri is a lowered affinity of haemoglobin for oxygen

Question 27

Suggest two ways in which leghaemoglobin improves the performance of the
nitrogenase enzyme.

Answer 27

.transport of oxygen, for respiration to generate ATP
.removes oxygen so less
inhibition of enzyme

Question 28

Suggest a mechanism by which carbon dioxide could reduce the affinity for oxygen of
haemocyanin.

Answer 28

.CO2 forms
carbonic acid
.H2CO3 dissociates
into H+

Question 29

Outline why it is important that fetal haemoglobin has a higher oxygen affinity
than adult haemoglobin.

Answer 29

.low O2 in the placenta
.O2 transferred from adult to fetal haemoglobin