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AQA BIOL1 Biology Unit 1 Exam - 16th May 2011

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aaaaaaaah i feel like i havnt done anywhere near enough revision :frown:

bleh.
on all the practice papers ive done though im getting solid B's, and i got a mid C on it when i took it last January. So ill be happy with a B, trying to aim for an A though (well, i can wish cant i? xD)

Reply 241

TOO_BAD

im not looking forward to this i got a U in january, i have been practising loads and have had extra tutoring lessons but still coming out with 36marks on practice papers any advise ?

Reply 242

emmaaa65

describe the sequence of events in the heart cycle, including the roles of SAN and AVN in your answer. (5marks)

Reply 243

salsabil

Original post by TOO_BAD

im not looking forward to this i got a U in january, i have been practising loads and have had extra tutoring lessons but still coming out with 36marks on practice papers any advise ?

hi-five, i got a U as well.. but that ws bcuz i didnt put my hed 2 it!!
hopefully i shud b boosted up to atleast a B in this one!!!
why dont u like practise some fundemental revision Qs??
ill post thm here...gimme a minite! :smile:

Reply 244

Insanity514

Could someone go over inspiration and expiration? The pressure and volume changes involved in it?

Reply 245

jones_wise

Original post by emmaaa65

describe the sequence of events in the heart cycle, including the roles of SAN and AVN in your answer. (5marks)

- The SAN sends a wave of electrical activity across the atria, which causes them to contract.
- The AV septum prevents the electrical activity spreading to the ventricles.
- The electrical activity passes to the AVN, that is between the atria.
- There's a short delay (to allow ventricles to fill). The AVN sends a wave down the Bundle of His (between the ventricles).
- The Bundle of His branches into small fibres, and the wave of electrical activity is released and causes the ventricles to contract from the apex upwards.

Reply 246

salsabil

HERE U GO... PRACTISE ANSWERING THEM!! MY COLLEGE GAVE IT TO US!!

UNIT 1 FUNDAMENTAL REVISION

Cells and microscopes
1. State the main function of the following organelles: cell-surface membrane, nucleus, mitochondrion, lysosome, ribosome, rough and smooth endoplasmic reticulum and Golgi apparatus. State the function of microvilli.
2. What is the difference between magnification and resolution?
3. Why has an electron microscope a greater resolution (resolving power) than a light microscope?
4. What is the difference between a transmission electron microscope and a scanning electron microscope?

Fractionation and Centrifugation
5. What is cell fractionation?
6. Outline the main steps involved in differential ultracentrifugation, listing the order in which the main organelles of an animal cell would sediment.
7. Why is cell fractionation carried out in (a) ice-cold solution (b) isotonic solution (c) buffer solution?

Plasma membranes and lipids
8. Describe the structure of a plasma membrane based on the fluid mosaic model.
9. Using structural formulae, show how three fatty acids and glycerol join together to form a triglyceride.
10. What is the difference between a saturated and an unsaturated fatty acid?
11. What is the difference between a phospholipid and a triglyceride?
12. Describe the emulsion test for lipids.
13. State three functions of the proteins in cell membranes.

Diffusion, Osmosis and Active transport
14. Define diffusion, facilitated diffusion and osmosis.
15. Write out Fick’s law (the relationship between surface area, difference in concentration, thickness of the exchange surface and the rate of diffusion).
16. How are diffusion, facilitated diffusion and osmosis similar, and how are they different from each other?
17. Define active transport.
18. How does active transport differ from (a) diffusion, (b) facilitated diffusion?

Proteins
19. Using structural formulae, show how two amino acids join to form a dipeptide.
20. What is the difference between condensation and hydrolysis?
21. Define the primary, secondary, tertiary and quaternary structure of a protein.
22. Describe the biuret test for protein.
23. What are the two basic types of protein based on their molecular shape? Give a named example of each type.
Enzyme action and properties
24. What is the activation energy?
25. How do enzymes speed up chemical reactions?
26. Sketch graphs of:
(a) Disappearance of substrate against time
(b) Rate of enzyme activity against substrate concentration
(c) Rate of enzyme activity against temperature
(d) Rate of enzyme activity against pH
27. What is the difference between a competitive and a non-competitive inhibitor?
28. Why does a denatured enzyme stop working?

Carbohydrate biochemistry
29. What is a polymer? Name two types of important biological polymers.
30. Write down the structural formula for ?-glucose.
31. Using structural formulae, show how two molecules of glucose form maltose.
32. Which two monosaccharides condense together to form (a) sucrose, (b) lactose?
33. Describe how you would test for the presence of (a) glucose, (b) sucrose and (c) starch.

Carbohydrate digestion
34. What is digestion and why is it necessary?
35. What is the end product of starch digestion?
36. Name the two enzymes that are necessary to digest starch, and state exactly where they are found in the digestive system.
37. How can a starch agar plate be used to assay carbohydrase activity?
38. Explain what ‘lactose intolerance’ is and what its main symptoms are.

Carbohydrate absorption
39. List the adaptations of the small intestine for efficient absorption of digested food products.
40. What two transport processes are involved in the absorption of glucose from the lumen of the gut into the blood?

Disease and pathogens and cholera
41. What is a pathogen? What are the three main types of pathogenic organisms?
42. Name two interfaces in the human body that serve as common entry points for pathogens.
43. State the two main ways in which pathogens cause disease.
44. Give three examples of natural defence mechanisms that prevent the entry of pathogens into the body.
45. List the main differences between eukaryotic and prokaryotic cells.
46. Name the pathogen that causes cholera. What type of organism is it?
47. How is the cholera pathogen transmitted?
48. What are the main symptoms of cholera?
49. How does the cholera pathogen cause disease (produce these symptoms)?
50. Suggest three measures that might be used to limit the spread of cholera.
51. What is oral rehydration therapy and how does it work?

Lifestyle, correlation and causal relationships
52. What is ‘risk’?
53. List the lifestyle factors that increase the risk of getting cancer.
54. List the lifestyle factors that increase the risk of getting coronary heart disease.
55. List the changes in lifestyle that can reduce the risk of getting both cancer and coronary heart disease.
56. What is a ‘correlation’, and how is it different from a ‘causal relationship’?

Heart structure and function and the biology of heart disease
57. List: (a) the four chambers of the heart
(b) the two main blood vessels bringing blood into the heart
(c) the two main blood vessels taking blood out of the heart
(d) the names and locations of the heart valves.
58. What is the function of the heart valves?
59. What causes the (a) AV valve to open?
(b) AV valve to close?
(c) Semi-lunar valve to open?
(d) Semi-lunar valve to close?
60. What is the cardiac output and how is it calculated?
61. How do the SAN, AVN and Bundle of His co-ordinate and control the cardiac cycle?
62. What are (a) atheroma, (b) aneurysm and (c) thrombosis?
63. What is myocardial infarction and what causes it?
64. What are the two main types of lipoproteins in the blood, and what are their functions?

Lung function and the biology of lung disease
65. What is the gas exchange surface of a mammal?
66. Describe how mammals ventilate their lungs (i.e. the mechanism of breathing).
67. What is pulmonary ventilation and how is it calculated?
68. List the features of the gas exchange system in a mammal that make gas exchange by diffusion every rapid.
69. Name the pathogen that causes pulmonary TB. What type of organism is it?
70. List the main symptoms of pulmonary TB.
71. How is pulmonary TB transmitted?
72. Describe the course of infection of pulmonary TB.
73. List the ways in which pulmonary TB can be prevented/controlled.
74. How does pulmonary fibrosis arise, what are its main symptoms and what is its effect on lung function?
75. What causes asthma, what are its main symptoms and what is its effect on lung function?
76. What causes emphysema, what are its main symptoms and what is its effect on lung function?
77. Name four risk factors associated with lung disease.

Immunology
78. Describe the process of phagocytosis and the role of lysosomal enzymes in the subsequent destruction of ingested pathogens.
79. What is an antigen? Give an example.
80. What is an antibody?
81. Describe the general structure of an antibody.
82. How precisely does an antigen-antibody complex form?
83. Name two types of specialised white blood cells and the specific immune response with which each is associated.
84. What is cell-mediated immunity?
85. How do T cells kill infected cells?
86. What is humoral immunity?
87. What is the role of plasma cells and antibodies in the primary immune response?
88. What is the role of memory cells in the secondary immune response?
89. What is antigenic variability?
90. Why do people suffer from some viral diseases like measles only once and then become immune to them, whereas they may suffer from other viral diseases like influenza and the common cold several times?
91. What is a vaccine?
92. What is the difference between active and passive immunity?
93. Why does passive immunity confer only temporary immunity on the recipient?
94. What are monoclonal antibodies?
95. List three useful functions of monoclonal antibodies in science/medicine.

Reply 247

nosta

BIOL1 is actually very simple compared to every other unit. I sat this last year and ended up with a C, granted I hadn't done anywhere near enough revision for it. I'm resiting it now, hoping for an A. There are hardly any how science works questions which makes it easier than the other units. I've done all the past papers and I'm hitting As so hopefully *touch wood* this exam goes alright. I'm using the revision guide and the only thing it doesn't seem to cover is the disadvantages of SEMs & TEMs... anyone help me out?

Reply 248

salsabil

Have fun, iv got the answers if anybody needs them

Reply 249

emmaaa65

Original post by jones_wise

yeppp. i wrote an asnwer aswell to practise myself, but i realised its soooo long and has needless points. i always babble in exams and i think it actually makes me lose marks :frown:

First the atria fill with blood, causing the pressure to rise inside them. This rise in pressure causes the atrioventricular valves to open and blood flows from the atria into the ventricles. The ventricles remain relaxed at this stage. The stage is called diastole. The remaining blood from the atria is pushed out by contraction of the atrial walls, which is stimulated by an electrical wave by the SAN (this stage is called atrial systole). The pressure inside the ventricles then increases and becomes higher than the pressure in the arteries and the atria. This forces the atrioventricular valves to close and the semi-lunar valves to open. After a short delay, (allowing the atria to contract and push blood into ventricles) the AVN conveys an electrical impulse down the bundle of His, causing the ventricular walls to contract from the base upwards, ensuring all the blood is forced out into the aorta and the pulmonary artery. This stage is called ventricular systole.

Reply 250

Tericon

Original post by Insanity514

Could someone go over inspiration and expiration? The pressure and volume changes involved in it?

Inspiration - Active process (requires energy)

1. Intercostal and diaphragm muscles contract
2. Ribcage moves upwards and outwards, diaphragm flattens. This increases volume of lungs and so pressure decreases, this causes air to flow into lungs

Expiration - Passive process (no energy required)

1. Intercostal and diaphragm muscles relax
2. Ribcage moves downwards and inwards, diaphragm returns to curved shape. Decreased vol of lungs and so pressure increases, forcing air out of lungs.

Reply 251

jones_wise

Original post by Insanity514

Could someone go over inspiration and expiration? The pressure and volume changes involved in it?

Inspiration -
- The external intercostal muscles contract, moving the ribcage upwards and outwards.
- The diaphragm contracts (flattens).
- Due to the increased volume of the thorax, the pressure decreases inside the lungs - and so air is forced in, as the pulmonary pressure is less than the pressure of the external air.

Expiration
- The external intercostal muscles relax, moving the ribcage downwards and inwards.
- The diaphragm relaxes.
- The decreased volume increases the pressure inside the lungs. Air is forced out because the pulmonary pressure is greater than the pressure of the external air.

Reply 252

nosta

Original post by salsabil

Have fun, iv got the answers if anybody needs them

can you PM me the answers please

Reply 253

username459260

salsabil - could you post the answers??????????

thanks

Reply 254

TOO_BAD

Original post by salsabil

Have fun, iv got the answers if anybody needs them

Thanks very much :biggrin:

Reply 255

nasira372

Original post by salsabil

Have fun, iv got the answers if anybody needs them

Most of them Im ok with, thanks for the list. can You post the answers to these questions on here please

7c) Why is cell fractionation carried out in a buffer solution
8) Describe the structure of a plasma membrane based on the fluid mosaic model.
9) Using structural formulae, show how three fatty acids and glycerol join together to form a triglyceride.
11) What is the difference between a phosoplipid and a triglyceride
13) 3 functions of the proteins in cell membranes
62) What are (a) atheroma, (b) aneurysm and (c) thrombosis?
64) What are the two main types of lipoproteins in the blood, and what are their functions?
70) List the main symptoms of pulmonary TB.
74) How does pulmonary fibrosis arise, what are its main symptoms and what is its effect on lung function?
75) What causes asthma, what are its main symptoms and what is its effect on lung function?
76) What causes emphysema, what are its main symptoms and what is its effect on lung function?
77) Name four risk factors associated with lung disease.
78) Describe the process of phagocytosis and the role of lysosomal enzymes in the subsequent destruction of ingested pathogens.
79) What is an antigen? Give an example.
80) What is an antibody?
81) Describe the general structure of an antibody.
82) How precisely does an antigen-antibody complex form?
83) Name two types of specialised white blood cells and the specific immune response with which each is associated.
84) What is cell-mediated immunity?
85) How do T cells kill infected cells?
86) What is humoral immunity?
87) What is the role of plasma cells and antibodies in the primary immune response?
88) What is the role of memory cells in the secondary immune response?
89) What is antigenic variability?
90) Why do people suffer from some viral diseases like measles only once and then become immune to them, whereas they may suffer from other viral diseases like influenza and the common cold several times?
91) What is a vaccine?
92) What is the difference between active and passive immunity?
93) Why does passive immunity confer only temporary immunity on the recipient?
94) What are monoclonal antibodies?
95) List three useful functions of monoclonal antibodies in science/medicine.

(edited 12 years ago)

Reply 256

A_clizzy

is it best to write answers in sentances or just points e.g

Influenza virus causes influenza flu. The protein Neuraminadase & hemogluttinin act as antigens and trigger the immune response. These antigens change regularly forming new strains of the virus. Thus, the memory cells produced from infection won't recognise the different antigens. As a result, the primary response must reoccur meaning people likely to suffer from flu more than once. (Antigenetic variation)
as opposed to..
- Influenza virus cause influenza flu.
-antigens Neuraminadase and Haemolguttinin trigger immune response.
-antigentic variation occurs causing new strains of antigens.
-primary response repeats and symptos likely to occur.

would you get the same amount of marks for answering in that format since AQA are more bothered about keywords?