Biology AS Level Paper General Note : P12 M/J 2012

This is revision note for reflection that I made based on CIE AS Level Past Paper.

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Biology P12 M/J 2012

1. Eukaryotic cells size range are 1 x 10 micrometer to 1 x 10^2 micrometer
2. Chromatin are present in all eukaryotic cells but not present in prokaryotic cells.
3. The wavelengths of the visible light restrict the resolution of the light microscope
4. The diameter of virus particle are around 1.5 x 10^2 nm
5. Glycogen structure is an alpha glucose joined by glycosidic bonds involving carbons 1, 4 and 6
6. Amino acids, fatty acid, and protein contain C=O bonds.
7. The similarity between amylose and amylopectin : 
• They both contains 1, 4 glycosidic bond
• They both polymer of alpha glucose
8. Fructose gives a brick red colour when heated with Benedict's solution
9. The role of cholesterol in the cell surface membrane is to regulate fluidity of the membrane
10. Facilitated diffusion and osmosis are passive processes by which substances can enter a cell
11. Endocytosis is active process by which substances can enter a cell.
12. The order of events during mitosis :
• Two chromatids are joined together by a centromere
• Chromosomes line up along the equator of the spindle
• Centromeres divide
• Chromatids move to opposite poles of the cell
• Chromosomes uncoil
13. The process of transcription require ATP, DNA, and free nucleotide bases
14. tRNA structure : 
• There is a binding site for the attachment of a specific amino acid, as well as a different binding site for the attachment to the ribosome, in order to allow translation to occur
• There is a ribose-phosphate backbone with strong covalent phosphodiester bonds and areas within the polynucleotide chain where base-pairing by hydrogen bonding occurs.
15. Large animal has had to evolve a transport system because diffusion occurs slowly over long distances
16. Endodermis is the tissue that contain Casparian strip and suberin is the molecule that forming this strip.
17. Cell Walls are included in the apoplast pathway
18. The circumference (girth) of a tree is less in the middle of the day than night because there is less tension in the xylem vessels at night because the rate of transpiration is at minimum.
19. Carbon dioxide, glucose, white blood cells, antibodies are found in all blood vessels, lymph and tissue fluid
20. Nicotine is the component of the tobacco smoke causes an increase in blood pressure
21. About chronic obstructive pulmonary disease (COPD) :
• The patient coughs a lot, bringing up mucus
• The patient symptoms normally do not change
• The patient is normally over 30 years old
• The disease cannot be reversed by treatment
22. Elastic fibres and smooth muscle would be seen in a photomicrograph of the wall of the trachea.
23. To prevent a disease, dead bacteria may be injected into the body. This is produces an active and artificial type of immune response
24. Measles and smallpox are two diseases that caused by viruses
25. The role of decomposers in the nitrogen cycle is to convert proteins to ammonium compounds.
26. Only 4% of the energy from sunlight be fixed by producers during photosynthesis because a lot of sunlight reflects off clouds, is absorbed by pond water or does not strike chloroplast.