Biology Lab Report on the Effects of Adrenalin on a Daphnia

Essay by 123ooo321High School, 12th grade March 2006

download word file, 5 pages 5.0

Downloaded 64 times


For this experiment we tested the effects of different adrenalin concentrations (0.001%; 0.01%; 0.1%) on the daphnia flea. The daphnia was placed on a slide with cover slip in order to examine its heartbeat by using the microscope.


In this Lab we will study the effect of different concentrations of adrenalin on the heart rate daphnia, the water flea.

It is expected to recognize a threshold of the daphnia in its reaction the three different adrenalin concentrations, in terms of heart rate.


The endocrine system works with the nervous system to regulate and coordinate body functions. While the nervous system works quickly and sends messages directly to specific body parts, the endocrine system takes a longer time to produce a longer-lasting effect.

The system operates by releasing chemical messengers called hormones into the bloodstream, which travel throughout the body. Eventually the hormone reaches a target organ or tissue to cause an effect.

Growth and development, sexual maturation and reproduction, metabolism and homeostasis are some of the processes regulated by endocrine gland secretions. Endocrine effects can last hours, days, or even years.

Adrenalin is a hormone secreted by the adrenal glands that helps the body deal with stress. It produces the emergency, or "fight or fight," response and is secreted when sudden stress such as fear, pain, anger, or extreme physical exertion requires a burst of energy. Adrenalin causes increases in metabolic rate, breathing rate, heart rate, blood pressure, sweating and even blood clotting. It is a convenient hormone to study because its effect is relatively swift.

Materials required

Materials list

Daphnia culture, medicine dropper, slides, cover slips, bristles or threads, paper and pencil, paper towels, aquarium water, "recovery" beaker, dropper bottles containing adrenalin in various concentrations, microscope.


1) With a clean medicine dropper, remove a daphnia...