Purpose Research Hypothesis Materials Procedure Data Results Sources of Error Conclusions Bibliography

The purpose of this experiment is to determine the effect of different temperatures on the germination time of lima beans.

Seeds are formed in the ovary of a flower. The flower must be pollinated in order for the seeds to be fertilized. Using various methods of “transportation”, the seed leaves the flower that created it and hopefully lands in a spot where it may grow healthfully.

A seed consists of three main parts. The seed coat protects the seed’s insides. It is sturdy, consisting of layers of thick-walled cells, and often covered with a waxlike material. The embryo contains the plant; the stem and one leaf are present at this stage. The embryo is surrounded by the endosperm, which can be the seed’s digestion area, food supply, or both. The seed can be divided into sections, called cotyledons.

When a seed germinates, it swells with moisture, bursting the seed coat. This can happen because the seed has a shortage of food, or because the coat has been ruptured by an outside source. Some species will not use their endosperm until germination begins, and will therefore remain dormant unless the seed coat is broken. 300-year-old lotus seeds, found in dry Chinese soil, grew after their seed coats were punctured.

In some species, the cotyledons rise above the surface, protecting the bud of the plant and continuing its supply of nourishment for the young plant. These cotyledons open and wither when the plant no longer depends on them for its food supply.

Lima beans grow in pods on a variety of plant forms: some are pole beans, while others grow on both bushes and vines. The beans within the pod will grow until they break open the pod. They will then be dispersed.

It will take longer for those lima beans kept in cooler temperatures to germinate than those kept in warmer temperatures. The lima beans kept in the freezer will not grow.

1. Place one lima bean in the center of each napkin. Fold the napkin.
2. Place one lima bean in each pot.
3. Water each napkin so that it is thoroughly soaked, but also so that no excess water is in the pot.
4. Place the pots by pairs in four separate areas with noticeably variant temperatures. Measure the temperature of each space.  Place one thermometer in each testing area.
5. Check each pair of lima beans every 12 hours. Notice when germination begins in the plants. Make sure the temperature in each area remains relatively constant.

The beans in the dining room were exposed to artificial and natural light; the beans in the basement to artificial light, and the beans in the freezer and refridgerator no light. Considering that the lima beans kept in the dining room were the first to germinate, light may have been an uncontrolled variable.

Rather than checking the beans every twelve hours, a six-hour check would have been more accurate.

Due to activities keeping me from the beans at the appointed checking times, the specimens sometimes went unchecked and unwatered. Although partially out of my hands, more of an effort to check the beans and water them consistently would have been optimal.

1. Fuller, Harry J. “From Seed to Seedling.” The New Book of Popular Science. Grolier Incorporated. 1990.
2. Galston, Arthur W. Life Processes of Plants. Pages 51.  New York. Scientific American Library. 1994.
3. Pratt, Arthur J. “Lima Bean.” World Book Encyclopedia. 1963 edition.
4. Stone, Doris M. The Lives of Plants. New York. Charles Scribner’s Sons. 1983.
5. Wittwer, S. H. “Bean.” World Book Encyclopedia. 1963 edition.
6. Quinn, Vernon. “Seed.” World Book Encyclopedia. 1963 edition.