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AS Biology OCR revision

I am well stuck on making revision notes, and just wondering how people revise for it? I have just recently found using the syllabus might be the most effective way, coz revision guids just give too much or not enough information.
I have got some which I have done on Human Health and disease, and hope everyone would be kind enough to share their revision notes.

Human Health and Disease
Introduction to Health and Disease
Define Health and diseaseHealth is physical, mental and social well being. It is more than just being free from disease.
Disease is a malfunction of the mind or body leading to a condition of poor health.
Health is more than just simply the absence of disease, some may not suffering from the symptoms of a disease may have low physical fitness and may be developing a serious condition such as heart disease or lung cancer.
Categories of disease and illness
Social
Living conditions and behavior are factors in development of disease
Smoking related disease, TB
Physical
Permanent or temporary damage to the body
Stroke
Mental
Changes to the mind, with or without known physical cause
Schizophrenia, anxiety
Non infectious
Any disease not caused by a pathogen
Lung cancer, night blindness
Infectious
Organisms (pathogen) invade the body
malaria
Deficiency
Caused by poor diet
Rickets, xerophthalmia
Degenerative
Gradual decline in a function or functions of the body
Coronary heart disease
Inherited
An inherited genetic fault
Cystic fibrosis
Self conflicted
Damage to the body
Attempted suicide, drug abuse and lung cancer.
Reasons for collecting health statistics
Make comparisons between populations at the same time
Make comparisons between populations at different times
Find out which diseases are important
Find new, emerging diseases, such as SARS
Inform policy-making about providing resources in the health service
Find out how well government health policies are working
Investigate the spread of disease and investigate the likely causes.
Difference between standards of Health in MEDC and LEDC
LEDC
Poor sanitation leading to the spread of water-borne diseases like cholera, diarrhoea, dysentery and typhoid
Unsafe water that often contains the pathogen of many diseases
Densely populated cities and over crowded accommodation increasing the likelihood of air-borne diseases, such as TB and influenza being transmitted from person to person.
Widespread poverty leading to poor diet and a lack of doctors and health facilities to treat disease. Malnourished individuals are less able to fight infections.
Many developing countries situated in warmer areas of the world where pathogens and the insects can spread and reproduce rapidly and build up large populations.
More death at birth or in the early year of life.
MEDC
Both the incidence of infectious disease and the mortality associated with disease have been reduced.
Living conditions are substantially better than in developing countries, which improved hygiene, sanitation and nutrition.
Successful vaccination programmes, and antibodies are readily available to cure bacterial infections.
The relative affluence of developed countries brings an increase in deaths from cardiovascular diseases, cancer and road accidents, albeit that cardiovascular disease is more prevalent amongst the poorer sections of developed countries.
Degenerative disease associated with old age are often seen.
Explain the terms
Pandemic – an outbreak of disease that occurs across the world or across continents.
Epidemic – an outbreak of disease in a population.
Endemic – this describes diseases that are always in a population.
Advantages for health of the Human Genome Project are:
Genetic tests have been developed for inherited disease such as cystic fibrosis, more of these will be developed as now the sequences of the genes are known.
Tests have also been developed to find out whether people have inherited alleles of genes that increase the likelihood that they will develop diseases such as breast cancer and Alzheimer's.
Doctors will be able to diagnose diseases more accurately and choose more appropriate treatments, avoiding drugs likely to have side effects.
Gene therapy may be carried out to insert properly functioning alleles. This has already happened to treat a rare immunodeficiency disease.
Pharmaceutical companies may be able to develop drugs better able to target specific problems.
Medical researchers will have more data when looking for causes of disease and finding cure.

Diet
Components of a balanced diet
Sufficient energy for our needs provided by the macronutrients (carbohydrates, proteins and fat)
Essential amino acids (essential means can't be made by the body, must be in the diet
Essential fatty acids (linolenic acid and linoleic acid)
Micronutrients – vitamins and minerals
Water for replacing the water lost in urine, sweat, breath and faeces
Fibre for preventing constipation
Energy and nutrient requirements of people
Gender
Males require more protein because their growth is greater than females during adolescence, and after that stage they have a greater mass of tissue to repair and replace.
Males requires more of the vitamin B complexes that are needed for respiration and metabolism.
Males require more calcium and phosphorus in adolescence because they develop larger bones than females during this stage of growth.
Age
Energy requirements increase with age, up to and including adolescence, as growth is rapid during these years and physical activity is generally at high level. These energy requirements remain almost constant up to the age of 60 years, after which they decrease as physical activity diminishes and body mass often decreases.
Protein requirements increase with age, especially around puberty. This is because additional protein is needed for the rapid growth around adolescence and thereafter, to repair and replace cells.
Calcium and phosphorus requirements are greater in the first year of life as they are laid down in the bones of infants. The rate again increases in adolescence when the second growth spurt involves relatively rapid elongation of the bones. After adolescence, the requirements remain constant.
Requirements for other minerals and vitamins increases up to the age 20 years, but thereafter remains relatively constant.
Activity
The more physically active a person is, the greater their energy requirement. It follows that, compared to an office worker, a manual labourer requires a greater energy intake, especially of carbohydrate food.
Pregnancy
Energy during the last three months of pregnancy, when fetal growth is at its greatest and the mother has this additional mass to carry around.
Protein needed to supply the growth needs of the rapidly dividing cells of the fetus.
Vitamin A, C and D, although too much vitamin A can be harmful to the fetus in the early stages of pregnancy. For this reason pregnant women are recommended to avoid liver, which is very rich in vitamin A.
Lactation
More calcium, phosphorus and magnesium, as these are needed by the newly born to develop their bones.
More zinc because it is present in a number of enzymes, including those involved in growth and metabolism.
Dietary reference value
This is sets of figures relating to the requirements for energy and nutrient intake of all healthy individuals in the UK, this is sat by the department of Health in 1991.
The three DRV are:
Estimated Average Requirement – this is the population average
Reference Nutrient Intake – this is at the top end of the range and is enough for about 97% of the population
Lower Reference Nutrient Intake – this is at the bottom of the range and is enough for only about 2% of the population.
Use of Dietary Reference value:
Chefs and caterers to design appropriate menus for groups of people living in communities such as schools, old people's home and prisons.
Managers to plan food supplies for large groups of people.
Dieticians and others to assess the dietary needs of individuals, e.g. The elderly and pregnant women.
Individuals to calculate their own dietary requirements and to maintain or improve health.
Food manufacturers to provide appropriate nutritional information on food labels.
Describe the functions of:
Essential amino acids
Used to synthesis protein for growth and repair of cells
Essential fatty acids
Used to make phospholipids and fats
Vitamin A
Used to make rhodopsin for functioning of rod cells in the eye
Used to make retinoic acid, which aids cell development and growth, especially in epithelia.
Vitamin D
A steroid hormone that controls absorption of calcium from the gut and its deposition in bones.
Consequences of malnutrition
Energy
Stunting results from chronic protein-energy malnutrition, occurs in children from 2-5 years of age.
Wasting results from acute protein-energy malnutrition, occurs in individuals over 5 years of age. This is characterized by rapid weight loss in those who had near normal weight.
Kwashiorkor
Bloated appearance
Moon face
Apathetic
marasmus
Very think with wrinkled skin
Old man's face
Mentally alert
Anorexia nervosa
Muscles waste (including heart muscles)
Periods stop
Blood pressure falls
Hair becomes thin and sparse
Hands and feet are cold
There is increased susceptibility to infection
There are personality changes.

Reply 1

Just Grow up

Vitamin A
Night blindness – rod cells do not make enough rhodopsin so people can not see in dim light
xerophthalmia – the surface of cornea is scarred which leads to blindness
Poor defence against disease such as measles.
Dry, rough skin, as vitamin A is needed to make retinoic acid, which is needed to maintain epithelial tissues like the skin.
Vitamin D
Rickets – occur in Children the bone become soft and grow irregularly, the joints become swollen and limbs and the chest may be distorted. Typically the legs are bow-shaped.
Osteomalacia – occur in adults – this causes a softening of the bones, making them tender and painful, fracture of bone occur more easily. Muscle weakness as well as loss of appetite and weight.
Obesity
Coronary heart disease – caused by increased blood pressure and blood cholesterol.
Type II diabetes
Cancer
Osteoarthritis
Rheumatoid arthritis
Hypertension
Diet and coronary heart disease
High level of salt – increases hypertension.
High Blood cholesterol – contribute to the formation of plaques in the coronary arteries
High fatty acid intake – saturated fatty acid increases the risk of CHD
Eating dietary fibre – protect against obesity and reduce insulin levels in the blood, so reducing CHD.
Moderate consumption of alcohol – shown by some studies to reduce the risk of CHD.
Eating oily fish – such as mackerel and herring
Formation of heart attack
Those who are over-weight are twice as likely to suffer from CHD than those with acceptable BMI.
It is a Degenerative condition which involves the build-up of fatty tissue in the walls of arteries that supply heart muscles.
If these arteries become narrowed as a result, the flow of blood decreases and the supply of nutrients and oxygen to heart muscle decreases.
The muscle doesn't release enough energy, the heart becomes weak.
There may be a blood clot in the coronary artery, so cutting off the supply of blood to that area completely and leading to a heart attack.

Reply 2

undiscovered

Ooh, those notes are pretty useful. I'm retaking this module y'see...

Reply 3

brianfall

My technique was (using the Sunflower Book);

1. Read a chapter and while I'm reading it write down questions about anything I don't really understand.
2. Go back over the chapter answering all the questions, then do the SAQ's and questions at the end of the chapters.
3. Once I've done this for all the chapters, get the last 5 years worth of past papers and mark schemes and do them one at a time like this;
4. Do a past paper in exam conditions - even though I know I'm going to do really badly - no looking at my notes, and no taking longer than I would be allowed for real.
5. Mark it using the mark scheme. Make notes on what I got wrong.
6. Have another go at doing the ones I got wrong again. Mark them again. Keep doing this until I get it right.
7. Then, and only then, move on to another paper.

Last time when I did this, I got 38% in the first paper I did, then in the second one I got 10% more. I went up a few percent every time, until the last few ones I did I got 90%. In the real thing I managed to get 72%, which I was really pleased with.

I think this time I'm going to try and combine that technique with also checking through the syllabus. It's all down to how much time I've got.

From today, we have 2 weeks and 2 days. I need to draw up a timetable and plan my time, otherwise I'm never going to fit it all in!

Reply 4

undiscovered

2 weeks and 2 days? Aahhh! I'm really rubbish at learning 'gaseous exchange and exercise', 'smoking and disease' and 'immunity' - actually, all of it! I do like it though, and compared to A2 Central Concepts it seems very straightforward, but...rghararharha :biggrin:

Reply 5

shyopstv

My cell structure notes:

Microscopy
Magnification = Size of object
Resolution = Ability to distinguish between two separate points
An electron microscope has a higher resolution than a light microscope therefore mor cell organelles can be seen using an electron microscope
Magnification = Image / Object

Eukaryotic Organelles
Rough endoplasmic reticulum: Contains ribosomes which are the site of protein synthesis
Smooth endoplasmic reticulum: Carries out synthesis of lipids
Golgi apparatus: A stack of membrane bound vesicles. Packages macromolecules for transport around the cell
Mitochondria: A double membrane bound organelle which is involved in aerobic respiration. Inner membrane forms folds called cristae to increase surface area of membrane. An the cristae, glucose is combined with oxygen to produce ATP.
Lysosomes: Contains hydrolytic enzymes which in a white blood cell, digest bacteria. Enzymes are contained in the lysosomes to prevent necrosis (cell death)
Chloroplasts: Contain chlorophyll. Have a double outer membrane. Within the stroma there are other membrane structures called grana where photosynthesis takes place
Plasma membrane: A phospholipids bilayer containing proteins. These proteins include receptors, pores and enzymes. Responsible for controlled entry of water and minerals
Nuclear envelope: A double membrane around the nucleus containing muclear pores which allow exchange between the nucleus and the cytoplasm
Centriole: A hollow cylinder about 0.4µm long formed from a ring of microtubules which are used to grow the spindle fibres used in nuclear division
Nucleus: Contains DNA responsible for the individual characteristics of each cell. DNA is similar in all cells but depending on which type of cell it is, some genes maybe turned on or off. Division of the nucleus proceeds cell division
Nucleolus: Inside the nucleus. Produces ribosomes which leave the nucleus to take positions on the rough endoplasmic reticulum
Cilia: Move in a co-ordinated manner, each slightly out of phase with its neighbour so substances around the cell are made to move.

Comparing prokaryotic cells with eukaryotic cells

Prokaryotes
Average diameter = 0.5-20µm
Circular DNA lies free in cytoplasm
Naked DNA
Slightly smaller ribosomes (18nm)
No ER
Very few organelles none of which are surrounded by membrane
Cell wall present

Eukaryotes
Often up to 40µm and 1000-10000 x the volume of eukaryotes
DNA not circular and contained in nucleus
DAN associated with protein forming chromosomes
Slightly larger ribosomes (22nm)
ER
Many organelles, many are bounded by a membrane
Cell wall only present in plant cells

Types of tissue:
Squamous epithelium: Individual cells are smooth, flat and very thin. The cells fit together to provide a smooth, low-friction surface. E.g. alveoli – thinness allows rapid diffusion
Columnar epithelium: A single layer of tall cells all reaching to the basement membrane. Sometimes also contains cilia. E.g. lining of bronchus

Definitions:
Tissue: A collection of cells which is specialised to perform one or more particular functions. Cells can be all of one type (e.g. parenchyma in plants, squamous epithelium in animals) or of mixed type (e.g. xylem and phloem in plants, bone in animals)
Organ: Part of the body which is formed from more than one tissue and forms a structural and functional unit (e.g. leaves in plants, liver in animals)

We also need to be able to interpret pictures of cells but that is kind of hard to show here and we need to be able to draw a transverse section of a eaf which I will upload when I have done it!

Hope this has helped someone!

Yes, me!

Thanks guys, I thought I will be doing this all alone, ha.

Reply 8

Ms.8U88735

it helps to look at past exam papers and mark schemes to get an idea of how the examiner marks your paper cos afterall, it is what you write on the exam that you get your grade. so its worth really analysing past exam papers to get an idea on what the examiner expects.