OCR Bio - Module 3 Exam UPDATED ACTUAL
Questions and CORRECT Answers
explain what causes the fluctuation of blood pressure in the aorta [2] - CORRECT ANSWER -- contraction of
smooth muscle increases pressure
- relaxation of smooth muscle decreases pressure
Compare and contrast the circulatory systems of mammals and fish [6] - CORRECT ANSWER -similarities:
- closed circulatory system
- both have a heart
- both carry oxygen using Hb
- both have arteries/capillaries/veins
differences:
- mammals have a double circulatory system but fish have a single circulatory system
- in fish, their hearts only have 2 chambers but in mammals there are 4
- in fish, blood passes through two sets of capillaries before returning to the heart but in mammals, blood passes through
only one
- fish circulatory system is less sufficient at supplying oxygen but mammal circulatory system is more efficient
Explain why in bodybuilders, the visible vessels likely to be veins? - CORRECT ANSWER -- veins have thinner
walls and so bulge more
- have a wider lumen as it contains large volume of blood
- found closer to surface of skin
Suggest why reduced heart rate is sometimes seen in people who are very aerobically fit [3] - CORRECT
ANSWER -- heart muscles are stronger/thicker
- increased stroke volume
- increased volume of blood in ventricles
describe how pressure changes in the blood as it flows through the circuatory system from the aorta to the veins (aorta -->
arteries --> capillaries --> veins) [3] - CORRECT ANSWER -- pressure drops as distance from the heart increases
- greatest pressure in the aorta
- constant pressure in the veins
- fluctuation in pressure decreases from aorta to arteries
explain what causes overall change in pressure as blood flows from aorta to arteries to capillaries [2] - CORRECT
ANSWER -- blood flows into larger number of vessels
- total cross-sectional area of arteries is greater than aorta
- total cross-sectional area of capillaries is greater than arteries/aorta
explain why it is important the pressure changes as blood flows from the aorta to the capillaries [2] - CORRECT
ANSWER -- capillary wall is one cell thick
- high pressure will damage the capillary walls
state two advantages of keeping blood inside vessels [2] - CORRECT ANSWER -- maintain higher blood pressure
- increase rate of delivery of blood
- flow of blood can be directed
describe AND explain how the wall of an artery is adapted to withstand and maintain high hydrostatic pressure [4] -
CORRECT ANSWER -to withstand pressure:
- thick wall
- collagen layer
- which provides strength
- artery wall won't be damaged as it can stretch
to maintain pressure:
- elastic tissue layer
- to cause recoil
, - thick layer of smooth muscle
- narrow lumen
explain why the wall of the left ventricle is thick than the wall of the left atrium [3] - CORRECT ANSWER -- to
create more force
- to create highER pressure
- to push blood against greater resistance
- left ventricle pushes blood further/to all parts of the body
outline the reasons why insects and other animals need well-developed transport systems [3] - CORRECT
ANSWER -- high metabolic rate
- need large supply of oxygen
- diffusion not sufficient
- to maintain a steep conc. gradient
- SA:V ratio is usually low
explain how pressure changes in the heart bring about the closure of atrioventricular valve [2] - CORRECT
ANSWER -- when ventricles contract
- ventricular pressure increases
- to higher than atrial pressure
- movement of blood pushes the valves shut
Explain why the curve for fetal oxyhaemoglobin is to the left of the curve for adult oxyhaemoglobin [3] - CORRECT
ANSWER -- low partial of pressure of oxygen in placenta
- fetal Hb has higher affinity for oxygen
- fetal Hb takes up oxygen in low partial pressure
Outline the benefits of the Bohr shift to actively respiring tissue [2] - CORRECT ANSWER -answer should clearly
indicate importance of MORE
- actively respiring tissue need MORE oxygen
- to release MORE energy
- MORE carbon dioxide produced
- Hb involves transport of carbon dioxide
- bohr shift causes MORE oxygen to be released
describe the role of haemoglobin in transporting oxygen around the body [3] - CORRECT ANSWER -- Hb has
high affinity for oxygen
- oxygen binds to Hb at high p(O2)
- to form oxyhaemoglobin
- oxygen is released when p(O2) is low
describe how the hydrogencarbonate ions are produced in the erythrocyte [4] - CORRECT ANSWER -- carbon
dioxide diffuses into erythrocytes
- carbon dioxide reacts with water
- carbonic anhydrase catalyses the reaction
- forms carbonic acid
- carbonic acid dissociates to form hydrogencarbonate ions and hydrogen ions
state what is meant by the term health [2] - CORRECT ANSWER -- an individual's pyhsical and mental wellbeing
- and the absnce of disease
describe and explain how substances that are dissolved in the blood plasma, such as oxygen or glucose, enter the tissue
fluid from the capillaries [4] - CORRECT ANSWER -- in arterial end of capillary, hydrostatic pressure is higher
than oncotic pressure
- capillary walls are leaky/there are gaps in the endothelial cells in the walls
- plasma is FORCED out
- small molecules such as glucose and oxygen move out with the plasma
explain why cartilage is essential in the trachea [3] - CORRECT ANSWER -- support to keep airway open
- as during inspiration
Questions and CORRECT Answers
explain what causes the fluctuation of blood pressure in the aorta [2] - CORRECT ANSWER -- contraction of
smooth muscle increases pressure
- relaxation of smooth muscle decreases pressure
Compare and contrast the circulatory systems of mammals and fish [6] - CORRECT ANSWER -similarities:
- closed circulatory system
- both have a heart
- both carry oxygen using Hb
- both have arteries/capillaries/veins
differences:
- mammals have a double circulatory system but fish have a single circulatory system
- in fish, their hearts only have 2 chambers but in mammals there are 4
- in fish, blood passes through two sets of capillaries before returning to the heart but in mammals, blood passes through
only one
- fish circulatory system is less sufficient at supplying oxygen but mammal circulatory system is more efficient
Explain why in bodybuilders, the visible vessels likely to be veins? - CORRECT ANSWER -- veins have thinner
walls and so bulge more
- have a wider lumen as it contains large volume of blood
- found closer to surface of skin
Suggest why reduced heart rate is sometimes seen in people who are very aerobically fit [3] - CORRECT
ANSWER -- heart muscles are stronger/thicker
- increased stroke volume
- increased volume of blood in ventricles
describe how pressure changes in the blood as it flows through the circuatory system from the aorta to the veins (aorta -->
arteries --> capillaries --> veins) [3] - CORRECT ANSWER -- pressure drops as distance from the heart increases
- greatest pressure in the aorta
- constant pressure in the veins
- fluctuation in pressure decreases from aorta to arteries
explain what causes overall change in pressure as blood flows from aorta to arteries to capillaries [2] - CORRECT
ANSWER -- blood flows into larger number of vessels
- total cross-sectional area of arteries is greater than aorta
- total cross-sectional area of capillaries is greater than arteries/aorta
explain why it is important the pressure changes as blood flows from the aorta to the capillaries [2] - CORRECT
ANSWER -- capillary wall is one cell thick
- high pressure will damage the capillary walls
state two advantages of keeping blood inside vessels [2] - CORRECT ANSWER -- maintain higher blood pressure
- increase rate of delivery of blood
- flow of blood can be directed
describe AND explain how the wall of an artery is adapted to withstand and maintain high hydrostatic pressure [4] -
CORRECT ANSWER -to withstand pressure:
- thick wall
- collagen layer
- which provides strength
- artery wall won't be damaged as it can stretch
to maintain pressure:
- elastic tissue layer
- to cause recoil
, - thick layer of smooth muscle
- narrow lumen
explain why the wall of the left ventricle is thick than the wall of the left atrium [3] - CORRECT ANSWER -- to
create more force
- to create highER pressure
- to push blood against greater resistance
- left ventricle pushes blood further/to all parts of the body
outline the reasons why insects and other animals need well-developed transport systems [3] - CORRECT
ANSWER -- high metabolic rate
- need large supply of oxygen
- diffusion not sufficient
- to maintain a steep conc. gradient
- SA:V ratio is usually low
explain how pressure changes in the heart bring about the closure of atrioventricular valve [2] - CORRECT
ANSWER -- when ventricles contract
- ventricular pressure increases
- to higher than atrial pressure
- movement of blood pushes the valves shut
Explain why the curve for fetal oxyhaemoglobin is to the left of the curve for adult oxyhaemoglobin [3] - CORRECT
ANSWER -- low partial of pressure of oxygen in placenta
- fetal Hb has higher affinity for oxygen
- fetal Hb takes up oxygen in low partial pressure
Outline the benefits of the Bohr shift to actively respiring tissue [2] - CORRECT ANSWER -answer should clearly
indicate importance of MORE
- actively respiring tissue need MORE oxygen
- to release MORE energy
- MORE carbon dioxide produced
- Hb involves transport of carbon dioxide
- bohr shift causes MORE oxygen to be released
describe the role of haemoglobin in transporting oxygen around the body [3] - CORRECT ANSWER -- Hb has
high affinity for oxygen
- oxygen binds to Hb at high p(O2)
- to form oxyhaemoglobin
- oxygen is released when p(O2) is low
describe how the hydrogencarbonate ions are produced in the erythrocyte [4] - CORRECT ANSWER -- carbon
dioxide diffuses into erythrocytes
- carbon dioxide reacts with water
- carbonic anhydrase catalyses the reaction
- forms carbonic acid
- carbonic acid dissociates to form hydrogencarbonate ions and hydrogen ions
state what is meant by the term health [2] - CORRECT ANSWER -- an individual's pyhsical and mental wellbeing
- and the absnce of disease
describe and explain how substances that are dissolved in the blood plasma, such as oxygen or glucose, enter the tissue
fluid from the capillaries [4] - CORRECT ANSWER -- in arterial end of capillary, hydrostatic pressure is higher
than oncotic pressure
- capillary walls are leaky/there are gaps in the endothelial cells in the walls
- plasma is FORCED out
- small molecules such as glucose and oxygen move out with the plasma
explain why cartilage is essential in the trachea [3] - CORRECT ANSWER -- support to keep airway open
- as during inspiration
