Daphnia Magna Lab Report

Crayfish are decapods pertaining to the phylum arthropoda, which are invertebrates and contain an open-circulatory system.1 The system works by the hemolymph getting re-oxygenated in the gills before being transporting to the heart by brachio-cardiac veins and then pumped to sinuses that bathe tissues with oxygenated hemolymph.2 The crayfish contain a neurogenic heart that depends on neuronal input from cardiac ganglion.3 The neurogenic heart requires nerve impulses to produce contractions in contrast to a myogenic heart that can contract independently from the nervous system.3 The crayfish heart will beat due to the reaction of the ganglion to stimuli in the environment.4 Stimuli will affect the autonomic nervous system in the crayfish that control involuntary actions such as the heart rhythm.4 Neurotransmitters are the chemical signals in which the nervous system regulates both heart rate and contraction.3The autonomic nervous system breaks into two categories as parasympathetic system that is involved in relaxation of organs and the sympathetic system that will stimulate increased activity. Neurotransmitters can either increase or decrease heart rate by altering the patterns in neural activity of the heart.4 Crayfish are poikilotherms, which means they cannot metabolically thermoregulate thus conform to the ambient temperature in the water.

A variety of factors can change the heart rate of Daphnia. According to Richard Handy (2012), “The heart rate (which can be up to 300 beats per minute) can be monitored and counted in different conditions – for example changing water temperature, or changing the type

All of the chemicals and solutions conducted in the experiment were either from Pierce/Thermo Fisher Scientific or purchased from Sigma-Aldrich. Many of the concentrations were diluted in water or heated to a certain temperature to see how bed bugs would react to these different solutions. Scientists conducted two experiments to see how bed bugs reacted to different concentrations. The first experiment bed bugs were treated with adenosine nucleotides such as ATP, ADP, and AMP. After collecting data, the results show that there was little to no difference between bugs engorging on blood and ATP.

If I had a chance to do any of these experiments again, I would choose to go more into depth for the dampness experiment. I would hold the experiment for a longer time period so that I can prove that if the mealworms were allowed to remain on the damp surface for excessive amount of time, the amount of dampness would become harmful to the mealworms as their bodies might start to rot and get infected. If I were to do the food experiment again, I would worms in the soil before putting the food into the container. I would do this because when I gave the worms a thin slice of apple (not part of experiment), they all came up to the surface of the soil to eat the apple. I could tell that the worms ate the apple because on the next day, only the skin

This question requires knowing the Beadle and Tatum’s experiment with Neurospora crassa and the results. Neurospora crassa, which is a type of bread mold of the phylum Ascomycota, has provided a rich source of knowledge on “biosynthetic pathways.” Neurospora crassa was perfect substance for biosynthetic pathway experiment. Because it was cheap, easy to grow, and more importantly it is haploid for most of its life. Since Neurospora crassa is haploid, there exists only one copy of each gene so that researchers don’t need to consider about dominant and recessive alleles.

In the 1950s and 1960s , something weird happened in the estuaries next to the long island sound , new York and Connecticut . Birds of prey , ( eagles ) fed on fish in the estuaries had soaring concentrations of the insect killer DDT in their bodies. Even though when the water in the estuaries was tested , it had low concentrations of DDT. In consequence , poisons that dissolve in fat (such as DDT) , can become more intense as they upgrade up in the a food chain in a process called biological magnification. When the pesticide mixes with the water , algae and bacteria are effected with the poison .

After the food particles travel down the digestive tract, the waste gets released through the anus, which is “located on the ventral surface of the terminal appendage. The first and second pairs of legs are used in the organisms' filter feeding, ensuring that particles too large to handle are kept out while the other sets of legs create the stream of water rushing into the organism,” (Daphnia). 8. Describe the type of nervous

I tested Daphnias in a different environment with some high concentration of chemicals. The different environment experiment which included the ethanol, caffeine and spring water. Firstly, I used a transfer pipettes to grab a daphnia from its original habitat. Using a glass side on the microscope, I transferred the daphnia in the pipette to the glass slide. Adding 5% of ethanol to the slide enabled me to figure out how the Daphnia will act in that environment.

Introduction: All living organisms require oxygen to grow. Daphnia magna and Lemna minor (also known as Duckweed in its most common form) are no exceptions to this rule. Fertilizer is used to help plants, like Lemna minor grow. Plants give off the oxygen that other organisms, such as Daphnia magna, need. However, over-oxygenated environments can cause excess in the plant life.

The amount of water the plants need every day for their daily activities such as for growth and photosynthesis is small when compared to what is really lost because of transpiration. Plants have specialized pores called stomata which are in charge for allowing the passing of materials. The stomata pores are surrounded by cells called guard cells whose function is to expand and contract so that they can open and close the stomata. So for example when the plant is losing too much water the guard cells close to stop that.

One error that was made during the experiment is that the Daphnia would be shaken as the petri dish was moved around. The table the petri dish was lying on would also be bumped while the experiment was being performed. If the experiment was performed again, it could be ensured that the petri dish containing the Daphnia is securely fastened in a static location where it would be unable to be shaken. Doing so would ensure that their environment is disturbed the least amount possible, which would keep the Daphnia from becoming stressed. This, in turn, would give the most accurate possible data as to the lifespan of Daphnia in different concentrations of copper

Elijah Brycth B. Jarlos IX-Argon 1. Multicellularity is a condition of an organism to have multicellular cells. An example of a organism who has multicellular cells are plants, animals, and humans. The main reason of why scientists have a hard time finding a good set of existing organisms to compare. Is neither the first set of organisms which is being compared is dying as fast as the second specimen is being examined or they just can’t find the right species.

Record this information at the end of every minute for ten minutes, in Table 1. For the second part of the experiment, using the pipette and water, place the water on the filter paper on one side of the behavior tray. Allow the filter paper to absorb the water therefore creating the wet environment. Next, place the Pill Bugs in the behavior tray and observe the amount of

DISSECTION METHOD TO APPROACH THE HUMAN CORACOID PROCESS OF THE SCAPULA 3.1 Introduction Dissection is a traditional approach to medical laboratory education(Waters, 2008). Using human cadavers one of the most widely used model in medical and clinical research for several decade .Considerable amount of literature have been published on different dissection methods of human body .(Romanes et al.,1986;Tank et al.,2008). These currant dissection manuals showed different approach to access different part of human body.

1) Hypothesis and Null Hypothesis for experiments For the experiment involving the red blood cells, the proposed hypothesis is that if blood cells are placed into a hypotonic solution of distilled water, then the cells will undergo a process called hemolysis where they swell and burst. For this experiment, the null hypothesis is that if blood cells are placed into a hypotonic solution of distilled water, then the cell will not undergo hemolysis. For the experiment involving the elodea plant, the hypothesis is that if the leaf of an Elodea plant is placed into distilled water, then the cells will become turgid, but will not burst because of the cell wall.