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Biol 1245 Circulation Lab Report
- Course
- BIOL 1245
- Institution
- Saint Louis University
This is a comprehensive and detailed lab report onCirculation for Biol 1245. *Essential!! *Vital resource,at a price that's fair enough!!
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BIOL 1245 Section 7427 November 2018
The Effects of Different Concentrations of Caffeine on the Pulsation Rate in Blackworms
ABSTRACT
Like most living organisms, blackworms have a closed circulatory system, which means
that blood is pumped through closed vessels at all times. In this experiment, blackworms were
examined to determine the effect of caffeine on pulsation rates. During the experiment, a
comparison was made between the effects of different concentrations of caffeine on the pulsation
rates in blackworms. Caffeine is a common stimulant that increases the activity of the central
nervous system. A T-Test was conducted in order to deduce whether increments of caffeine
concentration would increase, decrease, or have no effect on the pulsation rates in blackworms.
The comparison between caffeine concentrations of 0.1 mM, 1 mM, and 5 mM revealed that
there was a significant difference between all concentrations of caffeine and the control group.
Extensive studies have been conducted to understand the effects of caffeine has on an organism
and how certain drugs or chemicals can affect the pulsation rates in blackworms.
INTRODUCTION
Blackworms, formally known as lubriculus variegates, need oxygen to perform bodily
functions. This organism breathes oxygen and ultimately pumps out carbon dioxide through a
closed circulatory system. By definition, closed circulatory systems function when blood flows
through a circuit in series of vessels that are controlled by the heart (Freeman 2017). In
blackworms, blood transports nutrients, wastes and gases, such as oxygen. Moreover, they
undergo the process of obtaining oxygen with a dorsal blood vessel, a lateral blood vessel,
, ventral blood vessel, and muscles located within the tail to pulsate the blood vessels. The
anatomy of blackworms enable the organism to pump oxygen rich blood from the tail of the
worm to the head (Drewes 2001).
During this experiment, the effects of caffeine on pulsation rates in blackworms were
studied. Many scientists have conducted experiments to shed light on the effects of caffeine on
heart rates of many different species. Different chemicals (drugs) can have different effects on
the pulsation rate of the dorsal blood vessel. It has been shown that caffeine can increase blood
pressure and heart rate (Myers 1998). For example, a similar experiment using caffeine on
blackworms was conducted and researchers studied the blackworms’ response to caffeine. “At
low concentrations, worms may clump. As concentration increases, worms become very active.
They may curl up and stretch out at higher concentrations. Pulsation rate will increase” (Bohrer
2006).
The purpose of this experiment was to determine an answer for the research question:
Does the presence of caffeine in varying concentrations affect the pulsation rate in blackworms?
The null hypothesis (H0) is that there will be no difference in the pulsation rate in blackworms
between the control and the varying concentrations of caffeine. This would suggest that caffeine
does not have any effect on the pulsation rate in blackworms. The first research hypothesis (HR1)
was that the blackworms in higher concentrations of caffeine will have higher pulsation rates
than the blackworms in lower concentrations of caffeine and the control. This would imply that
caffeine does affect the pulsation rate in blackworms. Before the experiment, it was predicted
that the first research hypothesis would be demonstrated and that higher concentrations of
caffeine will result in the fastest pulsation rate in blackworms.
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