Cardiac system

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  1. a) The left ventricle releases a high amount of pressure approximately 15kPa in just under half a second whereas the right ventricle only releases a low amount of pressure approximately 5kPa in just under half a second. The left ventricle was at the same pressure of the aorta. The right ventricle is much slower at releasing pressure unlike the left ventricle. It took both ventricles left and right was both stationary after half a second and the pressure picked up again. 1 mark – you need to compare the numbers, what are the differences and then give a basic explanation as to why this might be

b) The pressure of the left ventricle was the same as the aorta at one point [JO1]then the pressure of the aorta dropped slightly and the increased after half a second. 1 mark – again, compare the numbers fully and provide a basic explanation – why does aortic pressure never drop below 10kPa?

c) When blood is pushed into the ventricles by the contraction of the atrium, and then the atrium relaxes. Next the ventricles contract this contraction is forceful, the high pressure forces the blood into the aorta this causes a pulse in the arteries all over the body. You actually need to talk about the uimpulse that controls the cardiac cycle. What does myogenic mean? Where does the impulse originate how does it make its way through the heart

  1. As the climbers went higher in altitude the mean concentration of haemoglobin increased. For example at 1000 altitude the concentration of haemoglobin was 12.5 [JO2]whereas at 4600 altitude the concentration ogof haemoglobin was 18.2[JO3]. 1 mark – what would the benefit be to the climbers?

a) Because lamb and pork already have a higher fat content than beef and chicken. For example fatty lamb and pork have 72g and 71g of fat whereas fatty beef and chicken have 67g and 5g. This is to do with the distribution of fat around the different animals bodies… If fat was deep within the tissue how easy would it be to trim?

b) Because foods such as fish, fish oils, eggs and dairy products have a higher content of vitamin D than lean meat. vitamin D is stored in fats. So, if you trim the fat off or have a low fat meat then there is consequently going to be less vitamin D

c) Lean pork originally has less fat content and what? but not less than chicken This isn’t an explanation it’s just a sentence isn’t it? more fat in lean pork resulting in higher energy per kJ than in chicken

because energy is stored in the fat; less fat = less energy

  1. haemoglobin

meat a condition called meat?

And nuts 2 marks

  1. Basal metabolic rate is the amount of energy required to maintain brain function and the rest of the body’s basic metabolism.2
  1. a) (i) minimum body mass: 61kg

Maximum body mass: 74kg 2

(ii) It shows the boundaries between being underweight, normal and overweight. Yes but WHY is it used, why is it preferred to just someones weight?

b) (i) women with the body mass between 39kg and 65 kg are fat than men[JO4]. Men that have a body mass of 33kg to 55kg have more skeletal muscle than women. Fewer women have lean muscle than men. Men have more a skeleton body mass than women. You need to talk about and compare the differences and discuss them

(ii) Everyone is different That is never going to get you marks. How are men and women different? What different demands do the yhave on there bodies.

a) because Energy is stored within chemical bonds and when they are broken energy is released. This can only be achieved through the oxidisation of food. The food is burnt in oxygen to oxidise it, breaking down the chemical bonds to determine the energy value of food.

b) Measurement of temperature What about the temperature? What else?

Mass of water in container (g)

Water temperature before

Water temperature after

Mass of food before

9. a) nicotine and carbon monoxide in the tobacco smoke damage the cardiovascular system .1 mark

b) By having a balanced diet and exercising regularly 2

a)

Blood is oxygenated in the lungs travels through the pulmonary veins into the heart. The heart muscle itself receives oxygenated blood through the coronary arteries that branch off from the aorta

  1. arteries

b) Because when both smokers and non-smokers cholesterol level increased over the years both groups had heart attacks. Basically the non-smokers didn’t have to smoke to increase their blood cholesterol level there many other causes of heart attacks. Read the question again – you are only supposed to be looking at non-smokers. You should be looking at the effect of cholesterol level on risk of heart attack and it is clear that it increases with increasing cholesterol level

c) For smokers the main cause for high cholesterol is smoking whereas for non-smokers there are many other reasons such as an unhealthy diet. No, this graph doesn’t show you that smoking causes high cholesterol it shows that you, while cholesterol levels increase the risk of heart attack in non-smokers, smoking AND high cholesterol increase the risk a great deal more.

d) When the carbon atoms are combined together by single bonds. You have to specify ONLY single bonds.

11. H2O, hydrogen, source, specific heat capacity, You’ve missed ones out here so I don’t know if any are in the right order. 2 marks

12. a) a hydrogen bond 1

b) Because they are not polar Dipolar means they ARE polar.

c) It is important because the water stays at a constant temperature for all the organisms. 1 – why is that important?

13. Polymers, helix, hydrogen Again you’ve missed loads out so I don’t know if any of thes are inb the right place. 1 mark

14. a) A= head B= tail You have to be more specific

A – glycerol (hydrophilic head)

B - fatty acid (hydrophobic tail)

b) Fatty acid Triglyceride

c) Condensation reaction 1

d) Fats So fats are good fats?

e) Triglycerides This isn’t a feature, and if it was you needed to say why it made them suitable for the function you should have suggested.

15. Blue to red, water, biuret Again answers missed out so I don’t know if these are in the right order or places. 1 mark

16. There are various risk factors for CHD one being age, the risk of CHD increases with age, over 80% of people who lost their lives to CHD are over 65 years old for example the development of atherosclerosis. Atherosclerosis is when the arterial walls thicken and lose elasticity.

Another risk is genetics which include ethnicity and hereditary factors for example if the parents have CHD then the children are most likely to develop it themselves in later life.

Smoking is another risk it damages the cardiovascular system by reducing the ability of red blood cells to transport oxygen. Nicotine stimulates adrenaline production which increases heart rate and causes the arteries to contract and raises blood pressure.

Alcohol in excess leads to high blood pressure levels and damage to heart and vessels.

High cholesterol levels lead to CHD. The cholesterol in the blood block receptors in cell membranes that metabolise lipids this leads to plaque on artery walls. 15 marks

17. Quantitative research means the measurement of everything in an experiment and qualitative research means the understanding of the experiments on how everything works. 1 mark

Quantitative research - capturing data numerically to create statistics easily measured Can be used to create spread sheets / graphs / comparisons etc.

Qualitative research is non-specific and non-numeric; used to gain understanding, develop ideas or hypothesis and is usually a base to lead on to quantitative research This sort of research is less precise and can be carried out using group discussions or observations

35

AS UNIT 1: TOPIC 2 Assignment B (TMA)

  1. There are many factors affecting enzyme activity one of them being temperature, enzymes have a specific temperature at which the work the quickest. For example for human enzymes its 37oC.

The pH scale is another factor, enzymes work more quickly and efficiently at a specific pH, for example for most enzymes this is pH 7-8.

Also there is enzyme concentration, when the concentration increases the rate of the reaction increases. Normally enzymes in cells are present in low concentrations.

Another factor is inhibitors this reduces the rate of reaction there are two types of inhibitors, a competitive inhibitor and a non-competitive inhibitor. Wha tare these? More detail required across the board here.

Substrate concentration also affects enzyme activity because when substrate concentration increases the rate of reaction increase as well. 5 marks

  1. Catalyst, energy, proteinsubstrate, active site, temperature, increasereduce – if the active site is altered it damages the enzymes efficiency

3 a) Osmosis is a special case of diffusion. It’s where water molecules can diffuse without difficulty through a cell membrane, whereas for other molecules it difficult for liquids to pass through it.1 mark Through semi-permeable membrane

From an area of low concentration to high concentration.

b) Facilitated diffusion is the transport of substances across a membrane by a trans-membrane protein molecule. 2 mark – which way does concentration go?

  1. a)(i) I don’t know You’ve got to attempt questions.

ii) Protein Sequence of amino acids

b) i) I don’t know A U G

ii) To diffuse into the ribosome and attach to mRNA No where near enough hdetail here.

  1. a) The difference between the term gene and allele is that gene is a section of DNA whereas an allele is a version of a gene. 2 marks – odd explanation

b) i) person 1

Person 2

Person 4: heterozygous

Person 5: heterozygous

Person 6: homozygous

0 marks

Person 1 IOIO (1 mark) An O group person MUST have IO IO because that is the only way the O group can express – because IO is recessive and thus you need two of them!

Person 2 IAIB (1 mark) This person has to be IAIB because their blood group is AB which denotes they have one of each dominant allele IA and IB

Person 4 IAIO (1 mark)

Person 4 cannot be IAIA because they cannot inherit IA off their father

Person 5- IBIO (1 mark)

Person 5 MUST be IBIO because their children have inherited IB which we now know the mother does not possess. Also, for person 7 to be O they must have inherited IO from both parents.

Person 6 IBIO (1 mark)

ii) AB

0 marks

If Person 1 has IOIO then Person 3 can only inherit IO off that parent (1 mark).

Person 3 can inherit either IA or IB from the other parent (1 mark)

can be either blood group A or B - IOIA or IOIB - IO is recessive (1 mark)

  1. The surface is thin; the walls of the alveoli are made of a single layer of flattened epithelial cells so the gases just need to diffuse through 2 thin cells and the alveoli is constantly moist because water diffuses from the alveoli cells into the alveoli. Basically there is 2 ways that maintain the concentration gradient there is blood flow on one side and air flow on the other. 4
  1. a) Meiosis has occurred reason being because when meiosis occurs the cell divides in to four separate cells. 2

b) Because when each cell is formed they each have half the chromosome number. What about crossing over of genetic information – look at the colours of the starting chromosomes and then at chromosome P.

c) In the sperm1

  1. The cell membrane surrounds all living cells, one of its functions are it controls how substances move in and out of the cell. Cell membrane is made of phospholipids, proteins and carbohydrates arranged in a mosaic structure. The phospholipids are arranged in a bi-layer meaning their heads facing outwards and the tails facing each other in the middle of the bi-layer. The heads are polar hydrophobic meaning they are water loving and the tails are hydrophobic fatty acids meaning their water hating. The phospholipids strengthen the membrane.

The proteins usually go from one side to the other of the phospholipids bi-layer and can also sit on the surface. The function of the proteins in the membranes are usually involved in transporting substances across the membrane, also the proteins on the outside surface act as receptors having specific binding site where hormones and other chemicals can bind.

The carbohydrates found on the outer surface and are attached to the membrane proteins. The carbohydrates are made of a variety of monosaccharide and form glycocalyx outside the membrane. The glycocalyx is involved in cell protection and cell recognition and antigens.

The cell membrane holds all of the cells content together. 20

  1. DNA is double-stranded it has two polynucleotide strands alongside each other. The strands are anti-parallel so they run in the opposite direction. The two strands are wound around each other to form a double-helix, joined together by hydrogen bonds between the bases. The bases are in pairs Adenine is with Thymine and Cytosine is with Guanine. DNA replication means that DNA with all its genes must be copied every time a cell divides. When the DNA is being copied the double helix unzips and two new strands are built up by the base pairing onto the tow old strands, DNA replication can take a few hours.
  1. a) Because only two people from the third generation have the condition it is recessive if it was dominant the condition would’ve been inherited through all three generations.

b) i) 0.043032

ii) That both parents have the condition and it mostly likely their offspring will have the condition.

c) They take a genetic screening where they are tested if they carry any specific conditions and diseases.

11. a) stage 1: transcription

Stage 2: translation

b) In the DNA

c) tRNA molecule collects amino acids


[JO1]Is this really acceptable scientific explanation and terminology?

[JO2]Units please

[JO3]Units please – 18.2 what?!

[JO4]Re-read answers please.

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