Otto Bahn wrote:
"Mark Fergerson" wrote

Hi,
My name is Shaniya and I am a Year 10 student at Alfriston College.
I was wondering if you could tell me exactly why blue light has an
effect on vegetation plants.
Any other information relating to this would be helpful.
This research is for my science project.
The answer to this would be highly appreciated.

Blue light has a shorter frequency than red or green and
thus has more energy. I.e.., it works better.

Ah, "works better" at doing what exactly though, huh?

Penetration. Any light that misses chloroplasts on one
side of the leave are likely to hit the backside of the
chloroplasts on the other side. Red tends to get absorbed
inside the leaf. Green doesn't penetrate at all.

OK, we're gonna have to sneak up on expliciticity.

We can't discuss "exactly why blue light has an effect on vegetation
plants" until we nail down what effect blue light has on plants. We know
they don't reflect it or transmit it, hence they must use it for
something once it's absorbed.

Shaniya, I don't want to do your homework for you, but I'll point out
that plants do several things with light: photosynthesis,
photomorphogenesis, photoperiodism, and phototropism.

Now do some Googling with these questions in mind: which of those
functions will be specifically affected by the
amount/orientation/periodicity of the available photons at the blue end
of the spectrum, and how? It will help if you know something about the
structures plants use to detect light. As in animals they're known as
photoreceptors, and contain specific sensor pigments. Unlike in animals,
those sensors are not primarily localized, but are distributed
throughout the plant with some concentrated in certain areas. Find out
where those areas are and which pigments are concentrated where.


Mark L. Fergerson