environmental effects on geno-phenotype (1 Viewer)

[mitch_f1]

Hey
In my text book it says that the environment can effect the way that a characteristic is expressed. Can someone please provide an example where a characteristic of an organism is present, but suppressed by the environment.

Thankyou
Mitch

 

[rhia]

Hey
In my text book it says that the environment can effect the way that a characteristic is expressed. Can someone please provide an example where a characteristic of an organism is present, but suppressed by the environment.

Thankyou
Mitch

the colour of the flowers of hydrangea are affected by the environment: the pH level of the soil. an acidic pH produces blue flowers, and an alkaline pH produces pink flowers.

plants that are grown in low light conditions will have their growth stunted as opposed to those grown in optimum lighting conditions.

http://en.wikipedia.org/wiki/Nature_versus_nurture this link might interest you.

 

[mitch_f1]

Ok, the hydrangea one I understand. But how is the growth gene supressed by low light. I thought it was just the fact that there was not enough energy being made to make the plant grow at it's proper rate?

Mitch

 

[rhia]

Ok, the hydrangea one I understand. But how is the growth gene supressed by low light. I thought it was just the fact that there was not enough energy being made to make the plant grow at it's proper rate?

Mitch

i guess you could consider it a nutritional deficiency. light is neccessary for photosynthesis, so without sufficient light... the plant isn't photosynthesising (as efficiently as it could), isn't producing energy to grow. i suppose you could also think back to the pressure flow hypothesis which explains how sugars are moved about e.g. to a fruit, or storage organ: if a plant isn't producing sugars from photosynthesis, then it isn't going to grow these things, either... so, is stunted in that respect as well. in addition, there are other environmental factors that effect the growth of a plant, such as oxygen, soil nutrients, climate, etc., not just light. the trait for height is there, but the environment prevents it from expressing itself.

same is true for humans: a nutritionally deficient human can have their growth stunted and other difficulties, including deficiency diseases.

 

[mitch_f1]

makes sense now...cheers

mitch

 

[Survivor39]

An excellent explanation, rhia.

 

[rhia]

to anyone who has had doubts about the effect of light on the growth of plants, the environment on the phenotype, here are the visuals of an experiment to test just that.

the control and experiment - radishes, from the same pack of seeds from mitre 10, where all good biologists go - were sprouted under the same conditions for 4 days. they were then separated and exposed to different conditions for 7 days. the control was grown in optimal conditions in regards to sunlight, while the experiment was sheltered from the sun in my cupboard.

amazing!

(sorry about the quality, can't fit in anything larger and a not enthusiastic enough to uplooad them somewhere.)

 

[mitch_f1]

Wow, I seem to be doing a similar experiment. I have chosen water however, and I cannot say mine is as successful. But there is a noteable difference in size, and healthieness.

mitch

 

[mitch_f1]

What could be another reason for the shortness of my plants receiving the most water. I already have that it could be due to nutrient leaching. Could it also be due to like roots becoming turgid or something similar.

The average heights of my population receiving the most water ended up being the shortest, above the two dead populations.

Thanks
Mitch

 

[Survivor39]

May be this particular plant has genetic defects.

Are all plants receiving the same amount of sunlight? Have you kept all variables controlled?

 

[mitch_f1]

I have controlled all variables. All plants received equal nutrients and sunlight. It was a sample of 15 plants.

 

[Dr_Doom]

we had this in the exam.. I think it asked for two examples and I put:

1) When in the sun, the pigment of your skin can darken causing a tan.

2) People who live in the mountains tend to be of less build than people living at sea level.

AM I RIGHT! OR WRONG?

 

[mitch_f1]

I'll rephrase the second question then: what role does water play in the structure, and strength of the plants. As I observed that after hot, dry days the plants receiving the least water had wilted. I know it's because the water has evaporated out, faster than it's being absorbed, but yeh, what role does water play in the structure of the plant.

Cheers
Mitch