Topic 1 - Lifestyle, Health and Risk

Question 1

Calculate the volume of a lumen that has a diameter of 3mm and a length of 10cm, in mm3 (use ∏r2h)​

Answer 1

∏ × 1.52 × 100mm = 706.86mm3​

Question 2

Blood pressure increases from 20mmHg to 132mmHg as blood moves from the pulmonary vein and leaves via the aorta​.

Calculate the percentage increase in blood pressure​

Answer 2

112 ÷ 20 × 100 = 560% increase​

Question 3

A Daphnia measures 2mm in length​

Calculate the image size in µm when the Daphnia is viewed under a ×40 microscope​

Answer 3

2000µm × 40 = 80 000µm​

Question 4

A student has a heart rate of 65bpm. ​

Calculate the length of time for one heartbeat, to two decimal places.​

Answer 4

60 ÷ 65 = 0.92 seconds​

Question 5

Blood plasma contains glucose dissolved in water. Glucose is a polar molecule that is taken up by muscle cells and used in the
synthesis of glycogen.​

Explain why water is a good solvent (2)​

Answer 5

Water is dipolar/has slightly negatively charged oxygen and slightly
positively charged hydrogens​

Water can surround polar/charged molecules allowing them to
dissolve​

Hydrogen bonds form between the water and polar/charged
molecules​

Question 6

A baby was born with an abnormal heart. There is a hole in the septum.

The baby survived due to the hole in the septum. Explain how the hole enabled the baby to survive (3)​​

Answer 6

The hole enables oxygenated blood and deoxygenated blood to mix​

Therefore oxygenated blood can get to the body/leave through the aorta OR deoxygenated blood can get to the lungs/leave through the
pulmonary artery​

Oxygen can be provided to the body cells to enable respiration​

Question 7

Veins and capillaries are blood vessels adapted for specific roles in the
circulatory system.​

Compare and contrast the structure of a vein and a capillary (3)​

Answer 7

2 from:​

Veins have valves, capillaries do not​

Veins have collagen/muscular walls/elastic fibres, capillaries do not​

Veins do not have pores, capillaries do​

Veins are more than one cell thick, capillaries are only one cell thick​

Veins have a large lumen, capillaries do not​

Must have for 3rd mark:​

Both have endothelial lining​

Question 8

Explain how the structure of a vein relates to its function (4)​

Answer 8

Large lumen as blood is under low pressure/reduce the resistance
to blood flow​

Valves to prevent the backflow of blood/to keep blood moving in one direction​

Smooth endothelial lining to reduce resistance to blood flow​

Thin walls/small amounts of collagen/elastic tissue/muscle tissue as the pressure in the veins is low​

Question 9

The photograph shows Daphnia (a water
flea). Daphnia can be used to investigate
the effect of chemicals on heart rate​

Explain why many small animals, such
as Daphnia, have a heart. (3)​

Answer 9

Small SA:V ratio, diffusion insufficient to
meet demands for oxygen and glucose ​

Organism has a high metabolic rate​

Heart enables rapid transport of oxygen
and glucose to cells for respiration​

Question 10

In a year group of 96, 16 students cannot roll their tongue. Calculate the % of students who can.​

Answer 10

96 – 16 = 80​

80 ÷ 96 x 100 = 83%​

Question 11

Blood pressure decreases from 15 to 3mmHg as it moves from the capillaries into the veins. ​

Calculate the % decrease in blood pressure when blood moves from the capillaries into the veins.​

Answer 11

12 ÷ 15 x 100 = 80%​

Question 12

What % of base A is present in a DNA molecule of 2000 bases if 400
of the bases are T?​

Answer 12

400 ÷ 2000 x 100 = 20%​

Question 13

The growth of seedlings was monitored. The mean start height was 0.2mm, the mean end height was 6.5mm. Calculate the % increase in height.​

Answer 13

6.3 ÷ 0.2 x 100 = 3150%​

Question 14

Describe what happens during the ventricular systole stage of the cardiac cycle (4)​

Answer 14

Ventricles contract ​

AV valves close to prevent backflow to the
atria ​

SL valves open ​

blood moves into the aorta/pulmonary
artery/towards body and lungs ​

Question 15

Atherosclerosis is more likely to occur in arteries due to the higher blood pressure in these blood vessels. A person with very high blood pressure has an increased risk of developing atherosclerosis.​

Describe how very high blood pressure could result in atherosclerosis (3)​

Answer 15

High blood pressure damages the endothelium of arteries​

Causes an inflammatory response​

White blood cells and cholesterol accumulate and an atheroma
forms​

Calcium salts and fibrous tissue accumulate and a plaque forms​

Question 16

Explain how atherosclerosis in one part of an artery could increase the likelihood of it developing in another part of the same artery. (2)​

Answer 16

Plaques narrow the lumen of an artery​

Results in an increase in blood pressure​

Increases the likelihood of further damage to the endothelium of the artery elsewhere​

Question 17

Blood clots can cause strokes or heart attacks. Explain how a blood clot develops (4)​

Answer 17

Damage to a blood vessel causes collagen fibres to be exposed​

Platelets gather at the damage site and release thromoboplastins​

Thromboplastins together with vit. K and calcium catalyse the
conversion of prothrombin to thrombin​

Thrombin catalyses the conversion of fibrinogen to fibrin​

Fibrin polymerises and forms a mesh to trap passing red blood cells, forming the clot​

Question 18

Explain how and why differential blood pressure is generated in a double circulatory system (2)​

Answer 18

Left ventricle has thicker muscle walls than the right ventricle (or converse)​

Left ventricle therefore pumps blood at higher pressure than the right because sending blood to the whole body (or converse)/lower pressure blood to lungs ensures efficient gas exchange and prevents damage to capillaries​

Question 19

Devise a method to investigate the effects of caffeine concentration on Daphnia heart rate (4)​

Answer 19

IV = range of 5 caffeine concentration (%)​

DV = heart rate beats per min​

CV = volume of caffeine used (cm3) using a pipette/time to acclimatise using a stopwatch​

Detail of method: e.g. immobilise in cotton wool/use a microscope to view HR/resting heart rate before treatment for validity​

Carry out repeats to calculate a mean HR for each concentration/exclude any anomalies​

Appropriate statistical test ​

Question 20

Explain the role of antihypertensive drugs in reducing the risk of atherosclerosis (4)​

Answer 20

Antihypertensives reduce blood pressure​

Lower risk of damage to the endothelium of arteries​

Reduced risk of the inflammatory response​

Reduced risk of atheroma/plaque forming​

Question 21

An anticoagulant called ‘Thrombin-blocker’ inhibits the formation of a blood clot. ​

Deduce the action of this drug (3)​

Answer 21

Inhibits thrombin enzyme active site/blocks formation of thrombin​

Thrombin therefore no longer catalyzes the conversion of soluble fibrinogen into insoluble fibrin​

No mesh formed to trap rbcs therefore no clot formed​

​

Question 22

People in Obese category I are more likely to develop high blood pressure than
people with a healthy weight. ​

Explain why someone who has a high blood pressure is at a significantly higher
risk of developing CVD. (4)​

Answer 22

Increased risk of damage to the endothelium of arteries​

Increased risk of inflammatory response/accumulation of white blood cells
and cholesterol​

Increased risk of atheroma/plaque/atherosclerosis developing​

Increased risk of blood clot forming at the site of atherosclerosis​

Lumen of artery narrows/elasticity of artery lost​

Resulting in further increase in blood pressure and increased likelihood of
atherosclerosis developing​

​

Question 23

Explain how the structure of starch relates to its function as a storage molecule (4)​

Answer 23

Amylose and amylopectin are both polymers of alpha glucose​

Amylose is a straight-chain with 1,4 glycosidic bonds, amylopectin
is branched with 1,4 and 1,6 glycosidic bonds​

Amylose is helical which enables compact storage of glucose​

Amylopectin has many terminal glucose molecules for rapid
hydrolysis for respiration​

Both amylose and amylopectin are insoluble and have no osmotic
effect on the cell ​

Question 24

Explain why water is described as a dipolar molecule (2)​

Answer 24

Unequal distribution of charge across the molecule​

Oxygens slightly negative and hydrogens slightly positive​

Question 25

Lipids (such as oil) do not dissolve in water, explain why this is the case (2)​

Answer 25

Lipids are non-polar​ Lipids cannot form hydrogen bonds with polar water​

Question 26

Name a substance lipids would dissolve in (1)​

Answer 26

Alcohol/another lipid/any non-polar solution​

Question 27

Describe how two glucose molecules join to form a disaccharide (3)​

Answer 27

Condensation reaction (with the loss of water)​ Between hydroxyl groups/between carbon 1 and 4​ Forming a glycosidic bond​

Question 28

Describe how triglycerides are formed (3)​

Answer 28

3 condensation reactions (with the loss of 3 water molecules)​ Between hydroxyl groups on glycerol and 3 fatty acids​ Forming 3 ester bonds​

Question 29

When triglycerides are broken down, the pH of the solution changes. State how it would change and explain why (2)​

Answer 29

Triglycerides broken down to produce 3 fatty acids and glycerol​ Fatty acids reduce the pH/make solution more acidic​

Question 30

Calculate the mass of an individual who is 182cm tall and has a BMI of 19.0 (2)​

Answer 30

1.822 × 19.0 = 62.94 kg​

Question 31

Calculate the waist-to-hip ratio of an individual whose waist is 60cm and hips are 82cm (1)​

Answer 31

60 ÷ 82 = 0.73​

Question 32

A patient visits their GP. They have a BMI of 30.1 and smoke infrequently. ​ Using your own knowledge, explain the advice you would give to the patient to reduce their risk of CVD (5)​

Answer 32

Reduce energy intake/lose weight/increase amount of exercise​ BMI of 30.1 increases risk of high blood pressure​ High blood pressure can damage endothelial lining of arteries leading to atherosclerosis/atheroma/plaque formation​ Quit smoking​ Smoking increases blood pressure further/ref to role in development of atherosclerosis​ Reduce salt/saturated fat intake​ Salt leads to high blood pressure/saturated fat increases cholesterol levels leading to atheroma formation​

Question 33

Maltose and trehalose are disaccharides. Trehalose is formed from two molecules of α-glucose​

Answer 33

Condensation reaction forming glycosidic bond​ Between hydroxyl groups on each molecule​ Water produced as by-product​

Question 34

Maltose and trehalose are disaccharides. Trehalose is formed from two molecules of α-glucose​ Compare and contrast the structures of trehalose and maltose (2)​

Answer 34

Both formed from two alpha glucose molecules/both contain a glycosidic bond​ Maltose has a 1,4 glycosidic bond, trehalose has a 1,1 glycosidic bond/in trehalose one of the monomers is inverted​