Biology Reference
In-Depth Information
a null hypothesis and an alternative, and the rejection of the null
hypothesis if the test statistic has a low probability of belonging to the
sampling distribution.
E
XERCISE
4-1
Germination and growth of seeds are affected by many factors: Type of
seed, type of soil, solar exposure, amount of water, and other
environmental factors. Magnetism is a powerful force affecting many
physical processes and could potentially affect the growth, development,
and germination of seeds. Scientist U. J. Pittman concluded, ''The roots
of some plants (winter and spring wheat, and wild oats) normally align
themselves in a North-South plane approximately parallel to the
horizontal face of Earth's magnetic field'' (Pittman [1970]). If the Earth's
own magnetism affects the way plants grow, perhaps added magnetism
will affect their rate and quality of growth as well. The experiment
described below is designed to explore these questions.
Use the observations/data provided via the Internet resources for this
chapter to formulate one or more hypotheses regarding the effect the
presence of a magnetic field may have on the germination of the seeds
and the growth of the seedlings. Use appropriate statistical techniques to
corroborate or reject these hypotheses. Present a clear summary of your
findings, including appropriate tables, plots, and charts. Based on your
findings, what additional studies would you propose to investigate the
stated hypotheses further?
EXPERIMENT
Materials
100 lentil seeds; one magnet (from an audio speaker, approximately 7 cm
in diameter, 1 cm in height) to provide the magnetic field; two bowls
(approximately 19 cm in diameter, 5 cm in height) to serve as flower
pots, cotton as a medium for initial germination; water (1 cup every
2 days); and potting soil (2.5 cups per bowl).
Procedure
1. Lentil seeds were placed on a layer of damp cotton for 24 hours to
help speed germination.
2. 50 seeds were then planted in each bowl, using the same type and
amount of potting soil.
