Biological Behaviour of Plants Under Certain Lighting
Conditions
Alexander**
Global Prestasi School
Abstract
Light effects plant growth in numerous ways, mainly in its ability to make food.
However light is not needed in germination. Though germination will only use food from the
seed, it will happens similarly but is not sustainable. Some seeds will germinate faster than it
being grown in a sustainable manner in which it will make its own food through
photosynthesis. Without photosynthesis the plant growth might happen in a different manner.
Thus observable differences should contrasts out of the research.
Key words: Germination, photosynthesis, mung bean, differences, light.
Introduction
The process of germination, as well
as plant growth, is studied and used in
many fields, mainly agricultural uses.
This is going to look at the
differences in the way the plant grows
physically which will differ because of the
external stimuli which is the light given is
different
A significant difference should
show up in the way the plant grows
overtime mainly in growth speed and plant
organelle factors.
There may be difference in color,
shape, speed, usage, size and many more
factors of the plant effected by the light
which will change how it operates and its
composition because of photosynthesis.
Experiment
A container was used to start the germination of 18 mung beans. Water was given to
make it damp but not to overhydrate the seeds. It was kept in a room at 26.0C for 24 hours
until it germinates (figure 1.1).
Figure 1.1
After it starts to germinate, 2 containers was prepared with distilled water to clean it
from the minerals left behind of the water and then left in a clean atmosphere to dry out. Then
some clean cotton was spread out and given evenly to the 2 containers (figure 1.2). After that,
10 ml of distilled water was given to each of the containers (figure 1.3-1.5).
Figure 1.2
Figure 1.3
Figure 1.4
Figure 1.5
With the growth containers prepared, the germinted seeds were cherry-picked for the
one that grows at the same rate and then transplanted (figure 1.6-1.7) into the now marked
containers A for the unlit, B for the lit one with 4 beans in each.
Figure 1.6
Figure 1.7
With that ready, I prepared 3 places in an weather(temperature) and air-quality
controlled room (the temperature is monitored carefully because it effects the growth). Two
for the lit one, one for direct sunlight (figure 1.8) and one under artificial light which blends
all light including UV light in there, which really blinds a camera with large sensor and no
UV filter equipped (figure 1.9) and the unlit one in a locked up metal safe in the same room
(figure 1.10).
Figure 1.8
Figure 1.9
Figure 1.10
All of the other variables were kept constant such as temperature in lit (figure 1.11)
and unlit conditions (figure 1.12-1.13). And variables such as humidity and pressure were
kept constant with the vent in the safe. The water given daily was also constant at 2ml per day
which was carefully given and measured through a syringe to not disturb the seeds. (Figure
1.14)
Figure 1.11
Figure 1.12
Figure 1.13
Figure 1.14
Results and Discussion
The growth of those two batches was relatively linear after the first or second day. At
first no noticeable difference were seen when the new plants were growing. But after saveral
days there were noticeable differences like the speed, color, organelles characteristics ETC.
Starting from the roots, the lit one had darker colored roots and less root coming on
top of the growing material. Theres also a noticeable difference between the roots and the
stem in the lit one than the unlit one. The root on the lit one also has less hair like branches
on it probably due to the lower need in water.
The stem is really has a noticeable difference, the unlit one has a white stem that is
almost twice longer than the lit one. It also is made from not much solid material and is
mostly water, while the lit one is forming a green-purpleish stem that is stronger and more
rigid and may be starting to try to form cellulose for making wood from the impurities and
certainly forming glucose form the photosynthesis.
And the determining part, the leaf. The lit plant has a rich green colored leaf that is
normal and is used for photosynthesis and the two leaves are open. While the unlit plant has a
yellow organnelle that is just ready to become leaves but is still closed and waiting for a
stimuli, light.
Conclusion
With the light it will make the plant start photosynthesising and make its own food.
Without the light it will grow fast at first but wont be self sustaining soon enough.
References:
1. Cambridge checkpoint 7 CB page.7
