Qualification > Sciences
CHEM AND BIO HELP AND TIPS HERE
The Golden Girl =D:
um how do i revise for paper 6 and 1 chem IGCSE on the night/day before the Eaxm itself?
and
um how do i revise for paper 1 biology IGCSE on the night/day before the Eaxm itself?
thx in advance
~ A.F ~:
--- Quote from: the golden girl on May 02, 2010, 03:56:25 pm ---um how do i revise for paper 6 and 1 chem IGCSE on the night/day before the Eaxm itself?
and
um how do i revise for paper 1 biology IGCSE on the night/day before the Eaxm itself?
thx in advance
--- End quote ---
Past-papers...Past-papers
Of course if you have time, revise your notes first, then just keep on doing past-papers,even if you have done them before.
The Golden Girl =D:
thx A.F.
CatAly$t:
--- Quote from: The Mysterious Dude on May 02, 2010, 11:53:47 am ---Whoah, you dont need to know that much, simple that they dont work on viruses, because virusesbacteria do not show the characteristics of viruses. You will not be asked this question though, in the CIE spec.
You will be given questions like why has penicillin becomes less effective??
Because strains of Bacteria become more resistant to it.
--- End quote ---
thx to both of you....
K_M:
--- Quote from: saleemsamer on May 01, 2010, 02:27:27 pm ---any notes for
- outline the use of microorganisms and fermenters to manufacture the antibiotic
penicillin
- describe the role of the fungus Penicillium in the production of antibiotic penicillin
and
- discuss the adaptations of the leaf, stem and root to three contrasting environments, to include pond, garden and desert, with emphasis on local examples (where appropriate) and the factors described in the core.
--- End quote ---
The fermenters are used to manufacture antibiotics to provide a sterile environment and optimum conditions ie optimum temperature and pH. Microorganisms speed up the process of producing antibiotics.
Adaptations of plants:
POND: eg: canadian pondweed
- stomata present on upper surface only to absorb carbon dioxide and give out oxygen easily and transpiration is not a problem as water is in abundance.
- The upper epidermis contains chlorophyll as absorbing light energy through the water is difficult therefore it increases photosynthesis
- leaves are thing and ribbon-like in order not to get ruptured by water currents
- the stem contains air spaces to provide buoyancy and to allow diffusion of gases throughout the plant. This provide energy to absorb nutrients by active uptake as they respire aerobically
- stems are flexible and ribbon-like
- roots are virtually absent as water is in abundance hence they do not need to absorb water from the soil.
DESERT: eg: cactus
- leaves are reduced to spines to protect the plant from being eaten and to reduce water loss and in order not to get ruptured by strong desert winds
- stem contains chlorophyll to carry out photosynthesis, it is covered in cutilce to prevent water loss
- stem stores water and nutrients
- stem is short and juicy in order not to get ruptured by strong desert winds
- roots are long to provide anchorage and to reach the water table deep underground
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