6A:P1: literature review
Introduction:
The nature of this topic is to find out how daphnia magnas heart rate can be effected by certain
conditions in particular caffeine and alcohol, this was the topic chosen as previous research surrounding
this topic has already been completed in previous biology lessons using temperature as the condition so
some previous knowledge was available on the topic, this topic includes how to improve laboratory
skills, including health and safety and risk checks , planning a method and hypothesis, completing
calculations to check data and plot graphs
Main body:
Mainstream views on the topic:
Mainstream views found state that conditions such as caffeine and alcohol have clear effects on the
heart rate of daphnia magnas hearts, in addition to this other mainstream views state that using
daphnia to experiment on is not an ethical issue as they're in mass amounts and are considered a flea
and will often be bought to be food anyway and are the most effective subject to experiment on as they
are transparent so the heart is easily visible so is much easier to count for the heart rates
Alternative views found however state that the correlation between caffeine and alcohol to the
daphnia's heart rate isn't valid as some tests and reaserch provided has stated no evidential difference
between normal and affected heart rates , however this is a very rare and highly anomalous result so
cant truly be relied upon , in addition to that some people has an issue ethically with the use of a live
animal no matter if it’s a small water flea due to it being alive when its experimented on.
Background to hypothesis:
The reason for the chosen hypothesis is that it will be easily be able to prove or disprove and will be
easily able to have method based upon it to be able to prove that caffeine and alcohol have opposite
effects on the heart and that both have clearly visible results and in addition to that many articles
researched into have proved their hypothesis to be correct through conducting methods that will be
used in the planned method for this unit.
Key terms:
Heart rate: the number of beats per minute
Daphnia: this is the generalised term for the species of semi-transparent water flea that lives in
freshwater with one prominent eye
Sub-species- this is a term used which refers to two or more populations of species that are living in
different subdivisions of the species range
Reaserch studies performed:
Many research studies have been provided when searching this topic, however very few include how
caffeine and alcohol are the opposite to each other when effecting daphnia's heart rate, some reaserch
papers or articles produced are helpful as they include methods such as
, • snabbiologys page on how caffeine effects daphnia's heart rate: ‘Effect of Caffeine on Daphnia Heart
Rate’- Published: Jan 23, 2017, Modified: Nov 27, 2019 / By Dr. Isa - this page also provided the exact
details for how to complete a method to tests whether caffeine does effect heart rate
• Uk. Essays page on how both caffeine and alcohol affect heart rate of daphnia: ‘Effect of Alcohol &
Caffeine Concentration on Daphnia Magna’ - published November 2018 (no named publisher)- this page
also provided information and background on why this is a practical that is completed and some
information on results that can be taken
• asking lots page on it was not necessarily a study however was surrounding how only alcohol effects
heart rate: ‘How does ethanol affect the heart rate of daphnia?’ -published-?( last updated - 11th May
2020), no named publisher – this page provided a quick and reliable answer that got straight to the
point on how alcohol and how much alcohol affects daphnia's heart rates
New discoveries- not many if any new discoveries have been published as the discoveries published all
correlate with each other's results so unfortunately no new discoveries in this search has been found.
Questions asked:
Why daphnia?
Why do caffeine and alcohol have opposite effects on heart rate?
How effective are the results from these tests?
Will a pregnant or older daphnia effect tests results?
Will temperature of microscope light effect heart rate?
Method used to be followed
Many different pages have been used to factor into the method that will be used in chosen method as
only using one methods walkthrough on how to conduct the practical will lower reliability and cause
possible anomalies if not done correctly with enough searching, the three main pages that will; factor
into this method will be:
-snabbiologys page - https://snabbiology.co.uk/effect-of-caffeine-on-daphnia-heart-rate/
#:~:text=Method.%201%20Remove%201%20Daphnia%20with%20a%20pipette,then%20be%20carried
%20out%20with%20two%20...%20 - this page has information on the control variables of the
experiment which include temperature of the water and size and species of the daphnia which will be
considered when conducting the practical , it also includes how many concentrations will be needed to
ensure the validity of the results.
-practical biology's page - https://practicalbiology.org/control-and-communication/control-of-heart-
rate/investigating-factors-affecting-the-heart-rate-of-daphnia -This page includes the actual lesson
preparation which will be important when conducting a practical as if time management and planning
isn't considered then the method will not be as effective as it could be in addition to that it gave a good
and precise list of equipment required for this practical.
-biology corners page -Investigation: Daphnia Heart Rate (biologycorner.com) - this page has extra
information which states to turn the daphnia's lamp off when first placing the daphnia on the slide and
Introduction:
The nature of this topic is to find out how daphnia magnas heart rate can be effected by certain
conditions in particular caffeine and alcohol, this was the topic chosen as previous research surrounding
this topic has already been completed in previous biology lessons using temperature as the condition so
some previous knowledge was available on the topic, this topic includes how to improve laboratory
skills, including health and safety and risk checks , planning a method and hypothesis, completing
calculations to check data and plot graphs
Main body:
Mainstream views on the topic:
Mainstream views found state that conditions such as caffeine and alcohol have clear effects on the
heart rate of daphnia magnas hearts, in addition to this other mainstream views state that using
daphnia to experiment on is not an ethical issue as they're in mass amounts and are considered a flea
and will often be bought to be food anyway and are the most effective subject to experiment on as they
are transparent so the heart is easily visible so is much easier to count for the heart rates
Alternative views found however state that the correlation between caffeine and alcohol to the
daphnia's heart rate isn't valid as some tests and reaserch provided has stated no evidential difference
between normal and affected heart rates , however this is a very rare and highly anomalous result so
cant truly be relied upon , in addition to that some people has an issue ethically with the use of a live
animal no matter if it’s a small water flea due to it being alive when its experimented on.
Background to hypothesis:
The reason for the chosen hypothesis is that it will be easily be able to prove or disprove and will be
easily able to have method based upon it to be able to prove that caffeine and alcohol have opposite
effects on the heart and that both have clearly visible results and in addition to that many articles
researched into have proved their hypothesis to be correct through conducting methods that will be
used in the planned method for this unit.
Key terms:
Heart rate: the number of beats per minute
Daphnia: this is the generalised term for the species of semi-transparent water flea that lives in
freshwater with one prominent eye
Sub-species- this is a term used which refers to two or more populations of species that are living in
different subdivisions of the species range
Reaserch studies performed:
Many research studies have been provided when searching this topic, however very few include how
caffeine and alcohol are the opposite to each other when effecting daphnia's heart rate, some reaserch
papers or articles produced are helpful as they include methods such as
, • snabbiologys page on how caffeine effects daphnia's heart rate: ‘Effect of Caffeine on Daphnia Heart
Rate’- Published: Jan 23, 2017, Modified: Nov 27, 2019 / By Dr. Isa - this page also provided the exact
details for how to complete a method to tests whether caffeine does effect heart rate
• Uk. Essays page on how both caffeine and alcohol affect heart rate of daphnia: ‘Effect of Alcohol &
Caffeine Concentration on Daphnia Magna’ - published November 2018 (no named publisher)- this page
also provided information and background on why this is a practical that is completed and some
information on results that can be taken
• asking lots page on it was not necessarily a study however was surrounding how only alcohol effects
heart rate: ‘How does ethanol affect the heart rate of daphnia?’ -published-?( last updated - 11th May
2020), no named publisher – this page provided a quick and reliable answer that got straight to the
point on how alcohol and how much alcohol affects daphnia's heart rates
New discoveries- not many if any new discoveries have been published as the discoveries published all
correlate with each other's results so unfortunately no new discoveries in this search has been found.
Questions asked:
Why daphnia?
Why do caffeine and alcohol have opposite effects on heart rate?
How effective are the results from these tests?
Will a pregnant or older daphnia effect tests results?
Will temperature of microscope light effect heart rate?
Method used to be followed
Many different pages have been used to factor into the method that will be used in chosen method as
only using one methods walkthrough on how to conduct the practical will lower reliability and cause
possible anomalies if not done correctly with enough searching, the three main pages that will; factor
into this method will be:
-snabbiologys page - https://snabbiology.co.uk/effect-of-caffeine-on-daphnia-heart-rate/
#:~:text=Method.%201%20Remove%201%20Daphnia%20with%20a%20pipette,then%20be%20carried
%20out%20with%20two%20...%20 - this page has information on the control variables of the
experiment which include temperature of the water and size and species of the daphnia which will be
considered when conducting the practical , it also includes how many concentrations will be needed to
ensure the validity of the results.
-practical biology's page - https://practicalbiology.org/control-and-communication/control-of-heart-
rate/investigating-factors-affecting-the-heart-rate-of-daphnia -This page includes the actual lesson
preparation which will be important when conducting a practical as if time management and planning
isn't considered then the method will not be as effective as it could be in addition to that it gave a good
and precise list of equipment required for this practical.
-biology corners page -Investigation: Daphnia Heart Rate (biologycorner.com) - this page has extra
information which states to turn the daphnia's lamp off when first placing the daphnia on the slide and
