Biology Revision for "O" level examinations

Photosynthesis (photo- light  and synthesis- to make/ bring together) Photosynthesis is the process of converting light energy into chemical energy. It occurs in two stages. 1. Light dependent stage - the light energy from the sun is used to split water molecules into oxygen and hydrogen -oxygen is released as  a by-product -energy is stored in ATP                  6H 2 O -->  3O 2 + 12H +   + energy (ATP) 2. Light independent stage -hydrogen combines with carbon dioxide to form sugar (reduction reaction) -ATP from light stage provide energy for this reaction -this stage can occur in presence or absence of light (day or night)                 6CO 2 + 6 H +   -->  C 6 H 12 O 6 Products of photosynthesis: 1. The glucose is used  -during respiration to  release energy - converted and stored as starch for later use in plants -used to make proteins, other carbohydrates (like cellulose), fats and other substances plants require 2. The oxygen is give off as a w

Hello. You can join my Group on facebook. http://www.facebook.com/groups/224808647644986/

-You should be able to define diffusion. "Diffusion is a form of passive transport (no energy required) in which substances flow from an area of high concentration to an area of low concentration:" OR Diffusion is the movement of a substance from a region of higher concentration to a region of lower concentration. Diffusion is the movement of gas or solute molecules from a region of higher concentration to a region of lower concentration until they are equal (from  BBC  ) -E.g. of diffusion in animal and plants  1. Oxygen and carbon dioxide gases are small enough to pass from the alveoli of the lungs to the single celled    capillaries that surrounds the alveoli.  2. Diffusion occurs when digested food in the blood stream (high in concentration) enter individual cells (low concentration of nutrients).  3.Pl ants transfer food particles  from phloem and water  particles from xylem through the process of  diffusion .  A simple example of diffusion taking place

Hello folks. The internet is not just used for facebook. It is a wonderful source of knowledge. As students you need to be very careful how you manage your time on the internet.     Below is an awesome website. Please make full use of it. It is quite interactive and concise. While it was created for use by GCSE students, it does have relevant contents for CSEC students to make use of. All the best in your studies. http://www.bbc.co.uk/schools/gcsebitesize/science/

Hello everyone. I would like to congratulate all those students who have excelled at this years CSEC examinations. Only through hard work and determination can success be achieved. For students preparing for exams next year, I do have that you have spent the long vacation preparing for one of the most important year of your high school life. My best advice is to begin studying for exams now, if you have not already done so. Make a study timetable (and include relaxation time). Then stick to your study timetable at least      90 % of the time. With this I can guarantee that you will be successful. All the best in your studies!!

Cells Hello everyone. One of the first things we lean in Biology is cells. All living organism consist of cell, and many structures (organelle) within the cell are common to most organisms, with a few exception. So what is a cell? " A cell is the smallest unit of an organism that is considered living". There is a debate whether virus is a living organism or not, and that would be looked at later. Cell theory 1. All organisms are composed of cells 2. Cells are alive 3. All cells come from other cells. You should know the function of the following organelles and be able to identify them on a diagram. 1. Cell wall :       protection                           Not found on animal cells (but on plant, fungus and bacterial cells) 2. Cell membrane/ Plasma membrane: regulate what enters and leaves the cell. 3. Nucleus:         Contains DNA and controls the cell 4. Mitochondria:  Site of cellular respiration. 5. Chloroplast   :  Site of photosynthesis, and only found in

This is a very good online biology text suitable for "O" level studies. http://www.ck12.org/book/Life-Science-Honors-For-Middle-School/r1/

Check this link for a Biology test. http://www.scribd.com/doc/47575372/Exam-Bio-F4-T1-2010-11

Taxonomy All living things (organisms) have seven characteristics in common. They all: 1.  Reproduce - produce an offspring (organism of its own kind) 2.  Feed/need nutrients - make their own food (plants), or consume readymade food as a source of energy 3.  Respire - release energy from food with the aid/use of oxygen 4.  Grow - increase in size by getting taller or wider 5.  Excrete - get rid of unwanted substances 6.  Move - plants move parts of themselves while animals often move from place to place 7.  Sensitive -   plants and animals react to changes in the environment. Although all organisms have these characteristics, there are differences amongst them that enable them to be classified differently. Biological classification was originated in the work of the Swedish naturalist Carolus Linnaeus, where classifications were done based on shared physical characteristics. The science of classifying into ordered systems that indicate a natural relatio

The Characteristics of Life The common characteristics for life is that all lives are well organized, they need to use energy, they grow and they reproduce themselves, all lives can respond to environmental stimuli and maintain relatively stable internal environment (homeostasis).  Branches of Biology There are many subdivisions in biology. For example, if classified by the subject of the study, there are anatomy, botany (or plant sciences), marine biology, anthropology, zoology and microbiology. If classified by the functional studies, there are molecular biology, biochemistry, biophysics, genetics, physiology, cell biology, developmental biology and ecology.  To understand how life evolves and changes over the time, there is evolutionary biology.  All these branches are aimed to understand life, and the purpose is to better serve our human health and living conditions.  Medical science is overly based on biology studies. Tools To Study Biology The metric system is used for

Science and the Scientific Method     Science is an objective, logical, and repeatable attempt to understand the principles and forces operating in the natural universe. Science is from the Latin word,  scientia , to know. Good science is  not  dogmatic, but should be viewed as an ongoing process of testing and evaluation. One of the hoped-for benefits of students taking a biology course is that they will become more familiar with the process of science.      Steps in the scientific method commonly include: Observation: defining the problem you wish to explain. Hypothesis: one or more falsifiable explanations for the observation. Experimentation: Controlled attempts to test one or more hypotheses. Conclusion: was the hypothesis supported or not? After this step the hypothesis is either modified or rejected, which causes a repeat of the steps above. Reference:  http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookintro.html

Biology literally means "the study of life". Biology is such a broad field, covering the minute workings of chemical machines inside our cells, to broad scale concepts of ecosystems and global climate change. Biologists study intimate details of the human brain, the composition of our genes, and even the functioning of our reproductive system. Can a biology book give you the answers to these questions? No, but it will enable you learn how to sift through the biases of investigators, the press, and others in a quest to critically evaluate the question. To be honest, five years after you are through with this class it is doubtful you would remember all the details of meatbolism. However, you will know where to look and maybe a little about the process of science that will allow you to make an informed decision. Source: http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookintro.html

Hello everyone. The following website contains very useful contents that would help in your studies. Please check it out. http://wizznotes.com/biology "All men by nature desire knowledge" Aristotle

Here are some paper 1 question taken from GCE 'O' Level past papers. 1.A new cell is being examined.    Which feature would enable you to identify it as a plant cell or an animal cell? A The cell contains a single large sap vacuole space. B The cell contains glucose and amino acids. C The cell contains stored fat. D The cell surface membrane is partially permeable. 2. What is the function of chlorophyll in plants? A to absorb carbon dioxide B to absorb light C to absorb nitrate D to absorb water 3. Why is it important to include fibre in the diet? A It gives energy to keep the body warm. B It helps food pass through the gut. C It increases growth in young children. www.xtremepapers.net D It is easy to digest. 4. Which substance builds up in a muscle as a result of anaerobic respiration? A carbon dioxide B ethanol C lactic acid D water 5. Which processes return carbon dioxide into the atmosphere? A combustion and feeding B feeding and photosynthesis

Hello folks,  Check out this link for CSEC 2013 time table. Hope you have been studying!  http://www.cxc.org/examinations/timetables .