A. Shells in the evolving cephalopods proved to restrict motility. Internalizing the shell into a pen allowed the organisms to be more efficient swimmers since the now uncovered body made way for the development of fins and contractible mantle cavities capable of jet propulsion. Cephalopods are now able to float horizontally in water since shedding their system of gas-filled chambers in the shell. The increased motility through evolving the shell into a pen was advantageous to these organisms in order to escape predators and respond to their increased competition for prey.
B. There would be no evolutionary advantage for an earthworm to have a brain. The cerebral ganglion that serves as the earthworm’s “brain” receives external stimuli such as light, heat, and vibrations and relays that information to its specialized segments. The ventral nerve cord runs from the ganglionic mass down the entire length of the worm’s body, branching off into lateral nerves in each segment. The direct path of impulses from the cerebral ganglion to the segments proves no need for a more complex structure such as a brain.
C.
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For the smaller, less dominant male cuttlefish to fool their rival males, the cuttlefish disguises himself as a female through the use of the color-changing cells on his skin called chromophores. This disguise allows the male cuttlefish to sneak by the other herd of males and mate with the female. This camouflage has proven to be evolutionary advantageous as the female cuttlefish will select the “cross-dressing” male’s sperm packet 70% of the time.
D. Life Cycle of Malaria:
1. Parasites in the human grow and multiply in the liver before moving to the red blood cells
2. The growing parasites destroy the red blood cells, releasing their daughter parasites or merozoites that invade other red
Blufish is a Canadian company founded in Ottawa, Ontario, in 2012 by Youssef Chahrour, a 23 year old business mogul. At Blufish, Mr. Chahrour and his team created a new, innovative product that would assist the lovers of the outdoors in all their water purification needs!
Ross Wolff, Jennifer, and David Zarkower. "Somatic Sexual Differentiation in Caenorhabditis Elegans." Current Topics in Developmental Biology 83 (2008): 1-39. Web. 28 Feb. 2014. .
Blackfish is a 2013 documentary attempting to elevate public awareness regarding the orca that are being kept in maritime amusement parks, specifically SeaWorld, and the inherent danger of their captivity. The film is effective because it raises a set of important ethical questions for the viewer while presenting with a necessary fact-based style of documentation that does not evoke gratuitous scenes of abuse in order to inspire sympathy, unlike some of the other films that are intended to raise awareness about animal abuse.
The background of this article gives information that is necessary to understand the experiment. The shape of the pelvic girdle is an appropriate predictor of both phylogeny and movement in terrestrial vertebrates. However, in marine vertebrates, the gravitational forces typically applied to terrestrial pelvic girdles are not there and therefore have little impact on the shape of the girdle. Pelvic girdles of fish are generally not attached to the vertebrae and primarily are used as a place for muscles to attach and supporting of the fins. The authors discuss how in many cases the pelvic girdle could be removed and not result in any complications. However, there are some marine vertebrates that are capable of bottom walking on the ocean floor with their fins. In batoids, the pelvic fins are used for walking, which is when pelvic fins move in an alternating fashion, or punting, when both pelvic fins move at the same time. There is also augmented punting; this is when the vertebrate uses both the pectoral fins and the pelvic fins to generate more thrust, this action decreases the forces on the pelvic fins during a punt. While this locomotion would
Before tetrapods existed, all vertebrates were confined to living in aquatic habitats. The only animals that lived on land were arthropods. Through natural adaptations, the fish developed into amphibians. This colossal stage of change made necessary the evolution of new ways of breathing, locomotion, and reproduction. Paleontologists needed to understand how this transition took place. If the changes in anatomy of the fish developed on land, then they served the same purposes they serve today, such as walking. But what advantages would those same body parts give to the aquatic creatures still living in water? This is one of the questions the scientists are asking themselves. There have been a few hypotheses on this matter. The most recent one states that the transformations of the aquatic creatures happened underwater in order to help them survive. This time period is very difficult to study because there is a very small amount of fossils preserved. A...
This parasite is spread through the bite of sandflies. There are three different types of infections and they each show varying degrees of severity. The cutaneous form produces mild skin ulcers, mucocutaneous produces ulcers in the mouth and nose, and the visceral form of the disease starts with skin ulcers and then fever, low red blood cell count, and an enlarged spleen and liver. The parasite is detected by a microscope and visceral can also be found by doing blood tests. 12 million people are in infected in 98 different countries and 2 million new cases are found every year. The disease also kills around 20 to 50 thousand people a year.
Zooplankton is a very diverse group of organisms that form an integral part of the microscopic animals that make up plankton in the water columns of lakes, ponds, rivers, estuaries and open-ocean. These organisms play important roles in the aquatic food web and can greatly affect fisheries among species that rely on a diet of zooplankton early in their life cycle. Taking the time to study these microscopic organisms would be beneficial in regards to understanding the early lives of larval fish, as well as how abundance may affect water quality throughout the year. In addition to being a main player in pelagic food webs, zooplankton metabolism has a close connection with the regulation and exchange of carbon dioxide (CO2) between
Jellyfish are monsters of a sort. Jellyfish can distort things and shut down whole systems of government when they come in swarms. There are several types of jellyfish but one can have devastating effects. The everyday monster of the jellyfish causes fisheries to lose money, clogs power systems to shut down due to the masses of them and can shut down water filter systems. Jellyfish affect other fish and will kill people easily with their sharp points. Their tentacles are deadly weapons when jabbed with their points. The problem can be solved when the natural ecosystem is the same and jellyfish eats their prey.
Privet plant and different species of the Asian carp fish depict two instances when non-native species which were introduced in Tennessee causing problems. Privet is a flowering plant native to Europe, Asia and North Africa (“Non-native Invasive Plants”). It has been introduced to grow as a hedge [boundary]. But, this plant once planted can take over the native plants and grow in dense groups. Currently, the Great Smoky National Park crews work up to “550 work hours each year” to remove privet plants (“Non-native Invasive Plants”). Different species of Asian carp were introduced in the United States in “1970” for aquaculture purposes, but were unintentionally introduced into the rivers when some escaped from the original ponds (“Asian carp
Cuttlefish, the chameleons of the sea, have many intriguing features and behaviors. Sepia Apama, also known as Giant Australian Cuttlefish, are not only the largest cuttlefish, but also some of the most unique and interesting. Their family, Sepidae, come from the phylum Mollusca, class Cephalopoda, and order Sepioloida (Sepia Apama). Their genus and species are Sepia and Apama respectively. They are known for their multiple year classes and breeding habits unlike any other cephalopod, including other species of cuttlefish.
The internal arrangements of squids consist of a mantle that surrounds the body's organs, as with most mollusks. However, although mollusks are generally characterized as havi...
The loss of water to the external environment is a problem that all marine fish must deal with. This is because the water contains a higher concentration of solutes (salt) than the fish does (hyperosmotic to the internal environment). This results in an osmotic gradient in which water is lost from the fish to the environment and ions are gained by diffusion. And so the marine fish must continuously drink water to keep hydrated, while the ions are actively regulated by specialised glands via excretion. This is the case with Harlequin tuskfish, which need to constantly drink water and excrete ions to maintain a stable internal environment. The Harlequin tuskfish, like all marine fish has gills that excrete salt, and a reduced, inefficient (in
The reproductive strategies of fishes are often reflected in the anatomical differences between the sexes, male and female. The objective of a reproductive strategy is to maximize reproductively active offsp...
Malaria is caused by Plasmodium parasites found in mosquitoes that carry an infectious disease. It is spread from the saliva through a bite of an infected female mosquito. Only female mosquitoes feed on blood, so this is why females are the carriers and spreaders of Malaria. Once you are bitten by an infected female mosquito then it releases the parasite into your blood where it moves to your liver and expands. This causes your liver to burst sending the infection back to your blood stream spreading to other areas of your body.
The life cycle of O. volvulus is complex, and relies significantly on the blackfly. The life cycle involves many steps that could be interrupted to prevent getting the disease. The life cycle is as follows;