Essays on Daphnia

Introduction

All organisms including human beings are exposed to a myriad of toxins from within the environment .The food we eat, the water we drink and the air we breathe, soaps ,cosmetics and other chemicals used in our daily lives contain toxins. Almost everything within the environment if taken in sufficient amounts can turn out to be poisonous or harmful .Therefore; there is a need to apply quick and cheap methods of testing and to determine the amounts of toxins in substances. Toxicity presents a complex variation between individuals. An amount that can harm one individual may not harm the other person. ...

- Hypothesis: Gymnosperms and Angiosperms have evolved structures similar in function to adapt to conditions on land - Materials - Prepared slide of the sponge - Methylene Blue - Microscope - Prepared slide of Hydra - Weak solution of vinegar - Teasing needles - Living Daphnia - Depression slides - Methods:

Sponge

- A slide of sponge was placed on a microscope and magnification set at X40 - The structures of the sponge was observed and recorded - Some organisms were placed close to the tentacles and observed (Vodopich & ...

Abstract

Animals whose body temperatures are affected by their surroundings are said to be ectothermic. If an ectothermic organism is exposed cold conditions, the heart rate of the animal lowers. In high temperatures the heart rate of the animal is very high. Caffeine being a stimulant works by causing the nervous system to work faster. It further leads to the constriction of the blood vessels. The Daphnia magna sometimes referred to as the water flea lives in the fresh waters. It is an exothermic crustacean. The results of Table one shows that Daphnia’s heart rate lowers as temperatures the temperatures ...