BY: CONNOR CHUNG

Sunlight and Plant Growth

Big Question

Does amount of sunlight a plant receives have an affect on it’s growth?

Hypothesis

Plants use sunlight for photosynthesis to produce sugar, which is then converted into fuel. Plants use these fuel for it’s growth and it’s functions.

If the amount of sunlight given to plants varies, then I hypothesize that the plant that received the most amount of sunlight will grow the fastest and the plant that received the least amount of sunlight will grow the slowest.

Facts from Research

Plants uses photosynthesis to produce fuel.Plants need fuel to grow.Photosynthesis requires sunlight.The part of the world that receives most

sunlight have lush forests and vegetations.Amount of sunlight a plant receives is not the

only determining factor for a plant’s growth.

List of Materials

3 – 250 ml Beakers3 – medium sized onionsMeasuring tape200 ml of water Notebook for measurementsPencil

Procedures

1. Prepare a notebook for measurements.2. Label each beaker #1, #2, and #3.3. Fill each beaker with 200 ml of water.4. Place an onion into each beaker. Make sure

that the root of each onion is submerged in water. The level of each onion submerged should be same for all three onions.

Procedures (continued)

5. Place beaker #1 in an area that will have direct sunlight throughout the experiment.

6. Place beaker #2 in an area that will have no sunlight (inside of a closet with no windows).

7. Place beaker #3 next to beaker #1 on days Monday through Wednesday. Place beaker #3 next to beaker #2 on days Thursday through Sunday. This procedure will limit how much sunlight the onion in beaker #3 will receive.

Procedures (continued)

8. On daily basis at 9:00 P.M., observe the water level to maintain a consistent level of 200 ml in the beakers.

9. At the beginning of experiment, measure the onions to establish a base point. Every 3rd day, measure the length of the root and sprout.

10. Continue the project for 3 weeks.11. At the end of experiment, measure the final

growth and compare to your base point measurements to see if the hypothesis was correct or incorrect.

Control vs. Variable

In this experiment, the control will be the amount of water a plant receives. One of the interesting facts I’ve found during my research was that the sunlight is not the only determining factor for a plant’s growth. Amount of water received by the plant also has affect on it’s growth. In this experiment, I will keep a constant water level of 200 ml for all three beakers.

Variable will be the amount of sunlight each plant receives.

DATA COLLECTION

BEAKER #1 BEAKER#2 BEAKER #3SUNLIGHT NO SUNLIGHT LIMITED SUNLIGHTroot sprout root sprout root sprout

DATES:

11-01-2009 1.5cm 0cm 1.5cm 0cm 1.5cm 0cm

11-04-2009 2.5cm 0cm 2.0cm 0cm 1.8cm 0cm

11-08-2009 3.9cm 0cm 2.7cm 0cm 2.7cm 0cm

11-11-2009 4.3cm 0cm 3.0cm 0cm 3.5cm 0cm

11-15-2009 5.5cm 0cm 3.6cm 0cm 4.2cm 0cm

11-18-2009 5.9cm 0cm 4.1cm 0cm 4.8cm 0cm

11-22-2009 6.5cm 0.2cm 4.5cm 0cm 5.2cm 0cm

11-25-2009 7.2cm 0.2cm 5.0cm 0cm 5.5cm 0cm

11-29-2009 8.6cm 0.7cm 5.2cm 0cm 6.0cm 0.3cm

NET GROWTH 7.1cm 0.7cm 3.7cm 0cm 4.5cm 0.3cm

Observation and Comments

11/01/09

Placed Beaker #1 next to a window that receives sunlight throughout the day.

Placed Beaker #2 in a closet that receives no sunlight throughout the day.

Beaker #3 will be moved every 3 days to receive or not to receive sunlight to vary the amount of sunlight it receives - it will start out next to Beaker #1.

Constant water level of 200 ml will be maintainedTrimmed roots on all 3 onions to same length.No sprouts on all 3 onions.

Observation and Comments

11/04/09

Measured root of each onion. The measurements were taken from bottom of the onion to tip of each root. The measurements were take from the longest root of each onion.

Moved Beaker #3 next to #2 after taking measurements - Beaker #3 will receive no sunlight for next 3 days.

Observation and Comments

11/08/09

Moved Beaker #3 next to Beaker #1 after measurements. Beaker #3 will receive sunlight for next 3 days.

No sprouts observed on all 3 onions.

Observation and Comments

11/11/09

Moved Beaker #3 next to Beaker #2 after measurements. Beaker #3 will receive no sunlight for next 3 days.

No sprouts observed on all 3 onions

Observation and Comments

11/15/09

Moved Beaker #3 next to Beaker #1 after measurements. Beaker #3 will receive sunlight for next 3 days.

No sprouts observed on all 3 onions.

Observation and Comments

11/18/09

Moved Beaker #3 next to Beaker #2 after the measurements. Beaker #3 will receive no sunlight for next 3 days.

No sprouts observed on all 3 onions.

Observation and Comments

11/22/09

Moved Beaker #3 next to Beaker #1 after the measurements. Beaker #3 will receive sunlight for next 3 days.

Sprout observed on onion in Beaker #1.

Observation and Comments

11/25/09

Moved Beaker #3 next to Beaker #2 after the measurements. Beaker #3 will receive no sunlight for next 3 days.

Sprout observed only in Beaker #1.

Observation and Comments

11/29/09

Final measurements taken on all 3 onions.Sprout observed in Beaker #3.

Analysis of Data

In my experiment, Beaker #2 received no sunlight and grew only 3.7 cm of its root and did not sprout at the top.

Beaker #3 received limited amount of sunlight and its root grew 4.5 cm and did sprout with height of 0.3cm at top.

Analysis of Data (continued)

Beaker #1 received continuous sunlight and its root grew 7.1 cm and had a spout height of 0.7 cm.

Conclusion

This experiment tested my hypothesis that the plant that received the most amount of sunlight grew the fastest and the plant that received the least amount of sunlight grew the slowest.

The experiment showed that there was a direct relationship between how much sunlight an onion received with its growth. More sunlight an onion received, better it grew.

Reference

Measuring Plant Growthhttp://www.sciencebuddies.org/mentoring/project_ideas/PlantBio_measuring_growth.shtml

Photosynthesishttp://en.wikipedia.org/wiki/Photosynthesis

Photosynthesishttp://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html

Requirements for Plant Growthhttp://www.aces.uiuc.edu/vista/html_pubs/hydro/require.html

Answers.comhttp://wiki.answers.com/Q/How_does_sunlight_effect_plant_growth