Example seed lab report
Starving a Plant
Introduction:
Problem: This experiment is designed to see if a plant can be starved by depriving it of
carbon dioxide.
Background: Plants trap sunlight energy with the green chlorophyll in their leaves (Mr.
Schaefer’s plant packet, page 58). Plants use this energy to make their own food during a process
called photosynthesis (Mr. Schaefer’s plant packet, page 58). This food is a carbohydrate (Mr. Schaefer’s
plant packet, page 58). Plants make their own food by using carbon dioxide they get from the air
and water that they get through their roots (Mr. Schaefer’s plant packet, page 58).
Picture from (http://www.lifeadrift.info/ages-11-16/phytoplankon-extra.aspx)
Plants have structures called stomata on the bottom of their leaves
(http://www.ask.com/question/what-does-a-stomata-do). Stomata are small holes, or pores, that let
plants take in the carbon dioxide they need for photosynthesis (http://www.ask.com/question/whatdoes-a-stomata-do).
Picture from
(http://www.pcsd.k12.ny.us/bwoods/Regents%20Biology/Chapter%2019%20Plant%20Function/Chapter%2019%2
0Plant%20Structure%20and%20FunctionHome.htm)
Petroleum jelly is made by distilling the waxy petroleum material that collects on oil rigs
(http://chemistry.about.com/od/chemicalcomposition/f/What-Is-Petroleum-Jelly.htm). A commonly known
brand of petroleum jelly is Vaseline. It can be used to treat burns and dry, chapped skin
(http://chemistry.about.com/od/chemicalcomposition/f/What-Is-Petroleum-Jelly.htm).
Hypothesis: If petroleum jelly is slathered on the bottom of a plant’s leaves, then the
plant will starve and die, because the stomata will be plugged and the plant unable to get the
carbon dioxide that it needs.
Experimental Design:
Control Group description: The control group will be 5 young bean plants growing in a
cup filled with soil. These bean plants will receive everything a plant needs to grow healthy, like
adequate water, temperature and light.
Experimental Group description: The experimental group will be 5 young bean plants
growing in a cup filled with soil. These bean plants will receive everything a plant needs to grow
healthy, like adequate water, temperature and light. However, once the bean plants have 2
large leaves, they will have petroleum jelly slathered on the bottom of their leaves to plug up
their stomata.
Independent variable: The petroleum jelly given to the experimental group is the
independent variable.
Dependent variable: The plants’ health is the dependent variable.
Operational Definition of “Plant Health”: The plants’ health can be measured
quantitatively by measuring the plants’ height and numbers of leaves and how many plants
grew. The plants’ health can be measured qualitatively by recording the plants’ color and
overall condition and taking digital pictures of the plants.
Materials: 2 large plastic cups, 4 cups of soil, 10 bean seeds, metric ruler, petroleum
jelly, water, marker, paper, pen, digital camera, and an appropriate place to keep the plants.
Directions:
1. Use the marker to label one plastic cup “control group”. Use the marker to label the
other plastic cup “experimental group”. Identify the cups with the scientists’ names and
class hour.
2. Fill both cups with soil.
3. Plant 5 beans seeds in the control group cup. Plant the bean seeds about 2 centimeters
deep. Plant 5 bean seeds in the experimental group cup. Plant the bean seeds about 2
centimeters deep.
4. Water both cups. Be careful not to overwater them.
5. Care for the 2 groups of plants. Record the observations, as described in the operational
definition of plant health, in the science experiment journal.
6. When the experimental group plants have 2 large leaves, carefully slather petroleum
jelly on the bottom of their leaves. The goal is to fill in the leaves’ stomata with
petroleum jelly to prevent carbon dioxide from entering the leaves.
7. Continue to care for the 2 groups of plants. Continue to record the observations, as
described in the operational definition of plant health, in the science experiment
journal.
8. After enough data has been collected, dispose of the experiment and begin analyzing
the data and making conclusions.