# variation watch

1. am i correct in saying that if a graph shows a set of data like 2 'bumps', there is discontinuous variation between the 2 sets of data due to genetic factor? (mutation, polygenic etc) and continuous within each set due to environmental factors? (selection)

gd luck to all those takin exams tomoro!
2. environmental factors such as light, mineral ion availability (plants), water availability, diet (humans, animals)
discontinuous variation occurs due to genes.
so yes, you are right
3. Continuous variation occurs due to interactions between unlinked genes (i.e. more than one gene codes for the characteristic). Discontinuous occurs due to inheritance on single, unlinked genes (e.g. has sickle cell anemia or doesn't)

Continuous variation is ALSO affected by environmental factors - not just by them.
4. (Original post by orangazhang)
am i correct in saying that if a graph shows a set of data like 2 'bumps', there is discontinuous variation between the 2 sets of data due to genetic factor? (mutation, polygenic etc) and continuous within each set due to environmental factors? (selection)

gd luck to all those takin exams tomoro!
i'm sure that's not right!

from discontinous data you wouldn't able to draw a graph! (correct me if i'm wrong )

e.g. as the person said before you either have sickel cell anaemia or don't (though forget able the carriers because strictly speaking the sickel cell gene and the 'normal' gene are codominant)

Continuous data you can draw graphs for that show the distribution of a phenotype in a population, e.g. weight and height, they will show a normal distribution.
5. from discontinous data you wouldn't able to draw a graph!
You can draw a graph from discontinuous data, but its pretty pointless unless you have lots of different possibilities. Just to illustrate this, you could draw a graph of number of bricks per house (if you enjoyed that kind of thing!). Number of bricks are discrete, and therefore discontinuous data. But you can't 'join up the points' on the graph, so you get 'humps' like orangazhang said. Hope this makes sense
6. yeah, no problem...

i'm counting the number of bricks in my house as we speak, lol

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