Question

How can one gene mutation show different types of dominance?

Answer 1

maybe because some gene mutations are helpful. for an example the black plague there were some people with mutations and that was helpful for them cuz they didnt get sick. however the people without the mutation (which was dominant) became sick and died. Hope this helped.(ps i may not be right)

Answer 2

Good idea, but not quite what I meant. I'll try make it a bit clearer.
The question I am trying to answer says...

In peas, starch-branching enzyme is coded for by the sbe1 gene. A loss-of function
mutation in the sbe1 gene that affects the amount of starch-branching
enzyme produced shows incomplete dominance. However when the effect of
the same mutation is observed at the level of pea shape phenotype
(round/wrinkled) there is complete dominance of the wild type over the
mutation. Explain how one gene mutation can show different types of
dominance.

After a bit of research I think this might be Pleiotropy. But that still doesn't seem quite right to me. Pretty sure I'm missing something.

Answer 3

idk if you can apply the same concept of what i said earlier

Answer 4

I don't think so, you're talking about a single gene with only two alleles; dominant and recessive. Pretty sure it's got something to do with multiple alleles, or different metabolic pathways. Just can't quite figure out what.

Answer 5

pleitorpy is also a single gene that influences many phenotypic traits so maybe it is pleitorpy

Answer 6

Maybe, but I'm not sure how that would affect the difference dominance patterns. I would have assumed that it would be the same dominance pattern for both traits seeing as it's one mutation in one gene.

Answer 7

often times different mutations can happen in one gene. What other ideas did you have besides Pleitorpy?

Answer 8

Just multiple alleles. But again, doesn't seem right.

Answer 9

do you have a textbook you could refer to about it?

Answer 10

it might have something that will give you an idea

Answer 11

lol. I've been flipping back through multiple textbooks and course guide for ages! Can't really find anything similar to this question.

Answer 12

lol is it for a final exam because thats gonna be hard. Also what course are you taking

Answer 13

Yup. Old final exam paper. Got the exam tomorrow! Managing to answer most the questions but this one really has me stumped! Course is Biology of Cells.

Answer 14

good luck then i actually have a final exam in biology tomorrow also...

Answer 15

Stink. Feeling the pressure! Good luck!

Answer 16

thanks same to you sorry i couldnt help

Answer 17

Haha. You made me think. Just as good. :)

Answer 18

lol

Answer 19

The idea of complementation. One gene codes for an enzyme that codes for a protein. If the protein is malfunctioned then it may or may not do the right job and the protein will not give a specific phenotype.

Answer 20

One enzyme complements another in a biochemical pathway. Enzyme A needed for making product 2

1->2 ->3

And enzyme B needed to make 3 .

Answer 21

mutations usually show recessive character since its new, it may or may not be passed. Depends where the mutation happened

Answer 22

keywords:
halploinsufficiency
dominant-negative alleles
dominant gain-of-function alleles
semi-dominant alleles

additionally, most mutations are harmless and are not passed on to offsprings - mutations are lost as species die. they do not also provide adaptive advantage that result in evolutionary change.