Codominance & Incomplete dominance
The difference between Incomplete dominance and Co-dominance:The lecture is taken as the lastest and correct version.
For Incomplete dominance, neither allele has complete dominace over the other and hence both allele will NOT FULLY expressed themselves, instead, both allele express intermediate characteristic.
Example: Snap dragon
One allele codes for red flowers
One allele codes for white flowers
When bothe alleles are together, the phenotype expressed will be pink, which means both allele did NOT FULLY expressed themselves but expressed intermediate characteristic.
For Codominance, both allele expressed themselves FULLY as shown in the phenotype.
Example: ABO Blood group
I(superscipt A) codes for the production of antigen A
I(superscript B) codes for the production of antigen B
When both alleles are together, both characteristics are expressed FULLY, meaning that antigen A and B are produced in the blood. Hence co-dominance.
Example 2: Coat colour
One allele codes for white patches
One allele codes for red patches
When both alleles are together,
(i) pink patches indicate....?
(ii) white and red patches found together indicates...?
Answer:
(i) Incomplete dominace
(ii) Co-dominance
Final note: To differentiate look at the final expression and take note of FULL or Intermediate expression.
posted by MG-Biology @ 9:32 PM
4 Comments:
mr goh...from toking to my friends from other jcs, i noticed that they know about rhesus factor. what is it about and do we need to know?
hmm,sir, been wanting to ask u this question for some time...how is the thylakoid dapted to its function in photosynthesis?
Well, i answer your queries in two parts:
(i) The first question can be easily answered. For future questions such as these, please do a little research first. Sources can be obtain through text books (Campbell 6th edition) or even googles.
rhesus factor:
Group of antigens on the surface of red blood cells of humans which characterize the rhesus blood group system. Most individuals possess the main rhesus factor (Rh+), but those without this factor (Rh−) produce antibodies if they come into contact with it. The name comes from rhesus monkeys, in whose blood rhesus factors were first found.
The key to your query should be whether do you need to know it? The answer is that you need only to know when it is used in solving genetic related questions and the paragraph above is to aid your understanding. If you get confused, stop and dont waste time on it.
Please refrain from comparing from your friends from other jcs, the things you need to know are sufficiently covered and do not speculate too much. Clear your doubts with your tutors respectively (or through this platform)
The second part:
(ii) How is the thylakoid adapted to its function in photosynthesis?
I will post this in a new thread.
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