Unit 6: investigative project
Learning Aim A: undertake a literature search and review to produce an investigative project
proposal.
Assignment title: Project research
Investigating factors affecting the heart rate of Daphnia
P1: carry out a literature search and review into a chosen scientific area.
Literature search:
Questions
What is daphnia?
What factors affect the heart rate of daphnia?
What is caffeine? And how does caffeine affect the heart rate of daphnia?
Why do we use daphnia?
Do the daphnia have heart?
Key words
Daphnia
Caffeine
Heart
Heart rate
Stimulant
Depressant
Drugs
Miller, C. (2019). Daphnia pulex. [online] Animal Diversity Web. Available at:
https://animaldiversity.org/accounts/Daphnia_pulex/. [accessed 27 Feb 2022]
This article was published by the University of Michigan and reviewed by many different departments.
This article has proven to be reliable by referencing lots of sources which were helpful in the research,
however, the sources are out of date.
This article shows reliability by giving in-depth detailed information about daphnia, their habitat,
physical appearance, reproduction, behavior, food habitat, and daphnia’s importance.
It says that daphnia is the most common living organism of the water flea, which can be found in almost
every permanent and nutrient-rich part of the water. Daphnia populations are mostly found in lakes and
ponds. because daphnia are very small, they tend to live in a water column, there is enough light and
food to live. Daphnia moves up and down the surface of water depending on seasons and predators. It is
mostly done at night when there are not many predators.
The article gives a good description of daphnia’s physical appearance, it says that daphnia is also known
as water fleas, this name comes from the way they swim (jerky). Daphnias are a type of small crustacean
, and 0.2 to 3.0 mm long. Their body has a special feature called carapace, this allows the study of the
anatomy of this organism much easier, when carapace is very clear which allows internal organs of
daphnia to be seen, such as the heart and brain.
The article has also given brief information about their reproduction, daphnia reproduces both sexually
and asexually in a process known as parthenogenesis, where male gametes are not needed. This
procedure occurs primarily during the summer. Females will make up the majority of the daphnia
population. This is because there are more food sources and more suitable conditions in the summer.
Sexual reproductions, on the other hand, occur during the winter, when there are many favorable
conditions, such as less food resources and a lower temperature. Daphnia has a lifespan of 10 to 13
days. If they are in a predator-free area with enough food, this could increase to 100 days.
Even though daphnia is not directly used by humans, it is involved in many food chains and is a main
food source for animals such as fish, according to the article. Daphnia is a species that is widely used in
science investigations. This is due to the fact that they are inexpensive, tiny, and easy to store in the
laboratory. They're also sensitive to changes in water, and they react quickly. Because their heart can be
viewed using a microscope, their translucent shell makes them ideal for studies.
Daphnia is advantageous to an aquatic environment economically, and they are frequently employed as
a cleaning in fish tanks. However, because both organisms compete for food and oxygen, daphnia can
occasionally limit the population of other organisms.
www.newworldencyclopedia.org. (n.d.). Daphnia - New World Encyclopedia. [online]
Available at: https://www.newworldencyclopedia.org/entry/Daphnia
?msclkid=23e7731ac55f11ec899317739a33ba09 [Accessed 27 Feb. 2022].
This article also talks about daphnia and its importance. in terms of ecology daphnia are important
components of freshwater food chains, they consume algae and small organisms, but they become prey
for small fish. Daphnia re an excellent model organism for biological studies and experiments. The
translucent carapace makes them suitable for this. Daphnia, like other animals, are sensitive to alcohol
intoxication, making them an ideal model for researching and assessing the effects of the depressant on
the neurological system. The translucent exoskeleton, which lets the heart be seen, makes them ideal
subjects, as I have stated. Daphnia can also be used to investigate the impact of toxins on ecosystems in
specific locations. They are considered as an indicator due to their short lifespan and reproductive
powers. This article also discusses reproduction, but because the top article already did so, there is no
need to repeat it.