Who Needs Light?

Objectives:

To observe the effect of the absence of sunlight on a plant by comparing a plant with sunlight on it to one without. The control plant is the one in the sunlight and the unknown is the lack of sunlight. 

Predictions:

A plant needs these three things to survive: sunlight, soil, and water in the right amounts.

I think that if a plant didn’t get any sunlight it would be unable to get food and would die in three days. After one day its leaves would change color, the day after that they would turn brittle, and the day after that, they would turn brown and fall off the plant.

Observations:

We have two pansy plants, one labeled “A” the other “B”. 

One has yellow flowers and the other one has purple flowers. The flowers have three or four smaller petals and one bigger petal.

The plants have green stems with thicker stems in the center of the pot with thinner stems coming out from them. The stems have buds on them, and curly leaves.
The plants have approximately 30 leaves on a stem with approximately 15 stems each, so the plants have approximately 500 leaves each.

Monday, September, 10th: Each plant is getting a half cup of water. Plant “A” is staying on the table in the sunlight and plant B is downstairs in the very dark closet.

After one day, nothing changed.

After a week, nothing changed on plant “A” but on plant “B” the stalks looked a little ghostly. Each plant is getting a half cup of water. Plant “A” is staying on the table in the sunlight and plant B is downstairs in the very dark closet again.

Two weeks after starting, plant “B”s leaves are turning clear then brown and then falling off, while plant “A”s leaves are turning yellow then brown and falling off. The stems of plant “B” are in the process of being bleached clear while the stems on plant “A” are staying green. Plant “A” is staying on the table in the sunlight and plant B is downstairs in the very dark closet again.

Three weeks after starting, plant “B” has turned mostly brown with brownish-green stems and leaves and dark-blue and white flowers, while plant “A” has green and light green stalks and leaves and has several yellow wilted flowers on it. Plant “A” feels soft and does not make sound when touched, and plant “B” faintly crackles and feels rough when touched. Plant “B” is dead.

Results:

At the start of the project, plant “A” and plant “B” looked the same except that plant “A” had yellow flowers and plant “B” had purple ones. After a week, the stalks on plant “B” started to turn ghostly looking and plant “A” stayed the same. After two weeks, plant “B” looked more ghostly and the leaves were turning clear then brown and falling off. Plant “A”s leaves were doing the same thing, except they were turning yellow instead of clear. The stalks on plant “A” stayed green. After three weeks, plant “B” died and plant “A” stayed the same as it had a week ago.

Conclusion:

Compared to what I saw, my overall prediction was correct. The plant died without sunlight. 
I predicted that the leaves on the plant would change colors, turn brittle, then turn brown and fall off and I was correct. I didn’t predict anything other than that, but the leaves turned clear before they turned brown, and the stems on the plant turned clear.
I predicted that this change would happen over a series of days, but in truth it happened over a series of weeks.
From my experiment, I can conclude that a plant needs sunlight to survive.