Qualification > Sciences
IGCSE BIOLOGY DOUBTS HERE !!!!
nid404:
--- Quote from: MKL on October 11, 2010, 05:23:23 am ---You need to be able to describe the function of the kidney in removing urea/excess water for Core, and need to be able to outline the structure of the kidney and structure + functioning of the nephron for Supplement, including the role of the renal capsule and the tubule.
Only negative feedback loops for maintenance of temperature in skin (Core) and maintenance of glucose content via insulin/glucagon (Supplement) are needed for IGCSE. At least that's what it says on the 2010 Syllabus.
--- End quote ---
You don't need the details though. Just the main idea that the product inhibits it's own production when it is in excess or when no more of it is required.
acash09:
Thanks very much Garfield! (I like garfield too! lol!)
Another question -
State the advantages and disadvantages of asexual reproduction
&
State the advantages and disadvantages of sexual reproduction
acash09
Amii:
Advantages and diadvantages of asexual reproduction
Advantages-
* The process is quick
* Only one parent is needed
* No gametes are needed
* All the good characteristics of the parent are passed on to the offspring.
* Where there is no dispersal (e.g- in potato tubers),offspring will grow in the same favourable environment as the parent.
* Plants tht reproduce asexually ususally store large amounts of food tht allow rapid growth when conditions are suitable.
Disadvantages-
* Thr is little variation created,so adaptation to a changing environment (evolution) is unlikely.
* If the parent has no resistance to a particular disease,none of the offspring will hv resistance.
* Lack of dispersal(e.g potato tubers) can lead to competition r nutrients,water and light.
Advantages And Disadvantages of Sexual Reproduction-
Advantages-
* Thr is variation in the offspring so adaptation to the changing or new environment is likely,enabling survival of the species.
* New varieties can be created, which may hv resistance to disease.
* In plants, seeds are produced, which allow dispersal away frm the plant, reducing competition.
Disadavantages-
* Two parents are usually needed(though nt always- some plants can self-pollinate)
* Growth of a new plant to maturity frm a seed is slow.
Hope it helps :D :D
Take care n keep smiling!! ;D ;D ;D
Deadly_king:
--- Quote from: acash09 on October 11, 2010, 04:37:13 pm ---Thanks very much Garfield! (I like garfield too! lol!)
Another question -
State the advantages and disadvantages of asexual reproduction
&
State the advantages and disadvantages of sexual reproduction
acash09
--- End quote ---
Advantages and Disadvantages of Asexual Reproduction
Asexual reproduction can be very advantageous to certain animals. Animals that remain in one particular place and are unable to look for mates would need to reproduce asexually. Another advantage of asexual reproduction is that numerous offspring can be produced without "costing" the parent a great amount of energy or time. Environments that are stable and experience very little change are the best places for organisms that reproduce asexually. A disadvantage of this type of reproduction is the lack of genetic variation. All of the organisms are genetically identical and therefore share the same weaknesses. If the stable environment changes, the consequences could be deadly to all of the individuals.
Hmmm Amii was quicker :)
Good job girl ;)
acash09:
Thanks guys and gals! Need something else, lol!
The drugs section in the syllabus - if someone has notes, could you post it here please?
I hate the drugs section ( except the good ones - antibiotics ), i never got those notes from my friends.
Much appreciated.
Acash09 - I'll keep smilin'! :P ;D
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version