What allows insects to walk on water? Melissa Stevenson Many insects are able to walk across water such as water striders. Observing some insects walking on water would lead into a few mini-experiments to discover why certain insects can walk on water, and if these types of insects would be able to walk on all types of water. Through mini-experiments, we will demonstrate what surface tension and a surfactant is so children could have a better understanding of why water striders can walk on water. Water striders legs are shaped to distribute their weight over a larger surface area so that it can better balance on the water. The surface tension of the water is able to support the water strider and prevent the insect from sinking to the bottom. …show more content…
The first mini-experiment would be to visualize surface tension with and without a surfactant. This mini-experiment can be conducted by dropping water one droplet at a time onto a penny and observing what happens (dome water droplet forming) (Kim, 2012). Soap could be added to the water and dropped onto the penny in the same fashion to demonstrate how a surfactant affects the water. The second experiment would demonstrate what it takes to break surface tension. This experiment can be done by observing how many pennies can be carefully added into a cup of water. The children will observe water forming an arc shape over the top of the cup to reduce tension and optimize surface area. The third mini-experiment will test the strength of surface tension by using different shapes of paper clips. The children will experiment to see which shape of paper clip will float on the water (the normal one). This will demonstrate that distributed weight distributed will allow something heavier than water to rest on top of the water due to a strong surface tension (like water striders legs). Through these three mini-experiments, children will observe what surface tension is, how surfactant effect water, and how surface tension allows water strider to …show more content…
•What happened to the water in the cup when pennies were added? Why did the water make an arc shape at the rim? •The water made an arc shape at the rim of the cup. Explain surface tension. Surface tension is something that happen when a liquid such as water molecules is held together tightly. The water molecules especially hold together tightly at the surface because there isn't any water molecules on the other side for them to grab onto. The water molecules at the surface hold together so tightly that a film/skin forms at the surface of the water creating a dome. Experiment 2: Visualizing surface tension with and without a surfactant •Were you surprised by the amount of water drops the penny could hold? Why do you think it could hold as many drops as it did? •Explain surface tension like in experiment 1. •Could you add more or less water drops to the penny with soapy water? Why? •Soap is a surfactant which reduces surface tension of water. The soap is interfering with the water molecules ability to hold together tightly causing th surface tension to be
In the lab the isopods were observed in a way to where behavior and structures could be properly recorded. The isopods were revealed to two dissimilar scenarios, normal temperature water vs. warm temperature water, to calculate which environment was most preferred. In each distinct scenario ten isopods were placed ten a choice chamber, one side being normal temperature (26.7celsius) and the other being warm temperature (43.3 celsius) , and observed for a total of ten minutes with thirty second intervals which was when we recorded our observations. After observations, it was seen that normal conditions was the most preferred environment by the isopods. In the scenario the Isopods exhibited taxis behavior, which is behavior caused by factors such as light, temperature, water and such. Nothing physical, but rather environmental.
There is no doubt that arthropods are an extremely successful group of animals, with an estimated 5-10 million species worldwide[1], and this can be attributed to having an exoskeleton; it provides many benefits, such as protection from parasitism and other threats. However, one major disadvantage of having an exoskeleton is the limitations that an inelastic cuticle can place on growth. The exoskeleton provides protection, but when freshly moulted the animal is soft and vulnerable, as well as having limited mobility and use of appendages; many seek shelter before moulting[2]. There are similarities and differences between the moult cycles of all the arthropods, however only crustaceans and insects will be discussed here.
4c. The functional significance of the response of elaters to moisture is that they help disperse spores by twisting.
Jellyfish move by expanding and contracting to push the water behind them. In between each contraction and expansion is a pause so that a vortex can be created ...
What reaction was conducted in this experiment and with what reagents? Was there a reason for this reaction beyond just synthesis of product(s)? What techniques were used to purify and identify the product(s) of the reaction?
Therefore, oil and water do not mix. This is why Oil does not dissolve when you run water over it. How does the oil wash off your hands if the water isn¡¦t soluble with the oil? This is where soap comes in. While soaps head is attracted to water its tail is attracted to non-polar substances such as oil. When oil and grease etc. mix with oil it creates a slightly polar substance because of the head group. This makes the oil soluble with water allowing you to wash off your hands with water and rinse the grease off.
In a phenomenon termed the “hydrophobic effect”, 4 surfactants act the way they do in
The external structure (fig.1) shows a hard exoskeleton, which is shed at intervals throughout their lives in order that they can grow longer. The exoskeleton consists of segments and the first section has a fusion of the thorax and the head4. The uropod at the rear of the Woodlouse is used for the uptake of water and this is achieved when they are pressed against moist surfaces5. Woodlice cannot retain water for long periods of time and because they have a large surface area to volume ratio they loose water quickly by diffusion6.
Mudskippers are fish which spend a lot of time out of water. It keeps its skin moist to absorb oxygen through it. Large crabs have a puddle of water on top of its shell for oxygen.
As we have seen, the features of the early tetrapods indicate that they were excellent swimmers but unable to walk on land. The evidence shows that they were descended from a fish ancestor. This means that legs were not evolved for use underwater, and that they adapted for the task of locomotion much later. Evolution always adapts existing structures to perform new purposes, rather than creating new structures. The principle of evolution is sometimes called preadaptation. There is no foresight involved; simply the lucky coincidence that a feature evolved to do one thing may turn out later to do another thing even better.
The platypus is covered with a thick water-resistant fur, excluding its bill and feet. It’s body it streamlined, has short limbs and webbed forefeet to propel itself through water using an alternative kicking motion. The webs on the for...
One of water’s most important properties is its polarity, which is due to the unequal sharing of electrons in the covalent bond. This causes water to be neutral as a whole, but with one end, the hydrogen side, positively charged, and the other end, the oxygen side, negatively charged. Each end is attracted to the opposite charged end of another water molecule. This, in turn, is what is responsible for the stickiness, or cohesion, between the molecules.
Thesis Statement In "When the Emperor Was Divine," the identity crisis faced by Japanese-American characters illustrates Du Bois's concept of double consciousness, revealing the internal conflict between their American identity and the imposed identity of the "enemy" during WWII. Introduction to W.E.B. Du Bois's concept of double consciousness describes the internal conflict experienced by marginalized groups in America as they navigate dual identities imposed by society. In the novel "When the Emperor Was Divine" by Julie Otsuka, Japanese-American characters face a profound identity crisis during their internment in WWII. This paper examines two incidents from the novel that highlight this crisis, analyzing how the characters react and the long-term effects on their sense of self.
There are three main variables that determine whether a liquid will posses capillary action. (Davis, 1995)
Water alone can’t remove dirt. Soap allows oil and to mix so the dirt can be effectively removed. Surfactants lower the tension in water and help break down the oil and grease. Detergents have hydrophobic chemical chains which are repelled by water, whereas hydrophilic chains are attracted to water. In general, hydrophobic and hydrophilic chains work together to attack oil and water and break them down faster and easier.