The stages in a typical jelly life history are adult, gametes, planula, scyphistoma , strobila , and ephyra. Moon Jellies reproduce sexually and asexually. The adult Moon Jelly reproduces sexually by releasing eggs, and then the sperm over the eggs. Jellyfish can be either male or female so one jellyfish can reproduce entirely on its own (gametes). Once fertilized the eggs develop into small, ciliated planula larvae. The larvae look for a safe protected place to nest and to continue to grow safely. They will stay there until they enter the polyp stage (scyphistoma). Once the scyphistoma has reached a certain growth stage they will begin to elongate and look like they are growing away from its base. This is when they will enter the strobili …show more content…
Annelids do have a body cavity and their body structure is round instead of flat. Annelids do not have a dead gut they have a mouth at one end and an anus at the other. While flatworms are unsegmented annelids are segmented worms. Flatworms have longitudinal muscles while annelids have circular muscles. This is one of the advances that make them advanced over the flatworm’s simple body plan. Annelids have a head which is followed by body segments throughout the length of the body and a tail. Throughout the body, each of these segments has its own muscles, nerves, and excretory organs. This allows for each segment to work independently of each other. Another, advancement in the body of the Annelids over the flatworm is that they have a true coelom, which is formed entirely within the mesoderm. Why does this make them advanced over the flatworm? Because the muscles in the flatworm are joined to the gut which means, they cannot move their muscles separately from their gut. In annelids, the movements of the gut are separated from the movements of muscles that are used for movement. The segmented body plan allows for a more advancement movement that the flatworms. The ability for each segment to carry out its own task also makes the Annelids more efficient than the flatworm. Annelids also have setae or little hairs on each segment that help them move flatworms don’t have this
The understanding of Saballaria cementarium's diet has not been thoroughly examined in much detail. Qian and Chia (1990) examined the role of detritus, form of eelgrass, as a food source for developing larvae of the organism. It is not known whether they are food limited. The experiment was conducted to reveal some facts about the feeding habits of the larvae in determining the development and growth of it. The invertebrate larvae's primary food source comes from the phytoplankton that is found in abundance at the bottom of the sea floor. The larvae fed with detritus were compared with those fed on equal concentrations of phytoplankton. Other tests were conducted to compare the degrees of survivorship among the larvae using varying concentrations of phytoplankton. Higher concentrations of phytoplankton, consumed by the larvae, yielded
Three pairs are autosomal, while the last pair of chromosomes are the sex chromosomes. Similar to humans, a XX pair of sex chromosomes will be a female, while an XY sex chromosomes will be a male. However, the determination of sex in fruit flies is somewhat different than in humans. The sex is determined by the X-chromosome’s ratio (X) to the autosomal chromosomes (A). For instance, when the X to A ratio is one or more, the offspring is a female, but when that ratio is less than one, the offspring is a male. Moreover, drosophila fly goes through three life stages until it becomes an adult fly. Approximately one day after the adult female lays the eggs, these eggs hatch into a larvae (Figure 1). During the larval stage, the larva stays in the nutrient media in order to eat and grow. The next stage is the pupal stage where the pupa forms a case around itself that helps metamorphism to occur. The pupa becomes darker in color and stiffer. Finally, when metamorphism is complete, the adult fly comes out being fully developed and having wings, legs, and eyes. An adult fruit fly may live approximately 30
Oftentimes, people can recall at least one song they know that is undoubtedly catchy because of its repetitive nature. That song can become a nuisance, when it will not leave your mind. When a melody gets stuck in your head, sometimes it could take a whole day to forget the tune. A certain tune can be stuck in your brain for many years! In Oliver Sacks’ passage, “Brainworms, Sticky Music, and Catchy Tunes”, he talks about “earworms”, or a pathological repetition. Sacks uses patterns of development to inform the modern reader about the dark side of music.
Flatworms belong to the phylum Platyhelminthes. They have the simplest body plan of all bilaterally symmetrical animals. They are called flatworms because their bodies are compressed. The mouth is the only opening into the digestive cavity the flatworms have. Food is taken in through this hole and wastes are discharged also through this hole. Flatworms have a well-defined nervous, muscular, excretory, and reproductive system. The flatworm distributes the food it digests through a digestive tube that branches throughout all of its body parts. The fact that the worm’s body is flat serves many purposes. It allows the worm to hid in small spaces, to fit into the opening of other animals if the worm is parasitic, and it means that all the cells are close enough to the surface for exchange of oxygen and carbon dioxide with the environment (Meinkoth 399).
Worms. It's not something that most dog-owners want for their beloved pups; but unfortunately, it's something that happens all too often. Worms and other parasites aren't just disgusting to think about, they are also potentially dangerous. At the first suspicion—or sight—of worms, you should take action quickly, so that your family pet doesn't suffer from upset tummy, grumpy behavior, or death.
This disease may be on the brink of being eradicated entirely but that doesn’t stop it from being one of the grossest things that anyone has ever seen. The parasite enters the body via unsafe drinking water. When people drink water infected with water fleas that have have been hosting the larvae of the parasite. There are no symptoms, to begin with, but about one year later, blisters on the feet or legs begin to develop and then the adult fully developed worm crawls out of the host body over a period of a few weeks. It’s said that the pain is intense and can incapacitate a person for weeks at a time. The pain can also continue for months after the infection. The parasite needs to infect a person at least once a year in order to continue. There were an estimated 3.5 million cases in 1986 but the disease has been greatly reduced over time and only 22 cases were reported in 2015. This disease will probably be the first parasitic disease to be completely eradicated in humans.
Forensic entomology is the learning of all types of insects and how they connect with criminal investigation. Forensic entomology can tell us how long since the offspring’s death which is known as postmortem interval (PMI) and whether the body has been relocated since putting one foot in the grave, and what injuries it may have suffered. At the start of decomposition, insects launch a new community by hatching eggs on the remains; the eggs will emerge into cankers (larvae) that will graze upon the human organs and tissues. A Forensic entomologists can figure out what specific bugs are presently in the body and gauge how long the body has been left unprotected by investigating how far along the cankers have come; although, what is found isn’t
Streptococcus equi equi is small non-motile, translucent cocci found in chains or pairs bacterium. It is commonly known as strangles. Strangles is one of the most common worldwide and highly contagious infectious respiratory diseases affecting horses, mules, and donkeys.
Fox, R. 2001. Invertebrate Anatomy OnLine: Artemia Franciscana. Lander University. http://webs.lander.edu/rsfox/invertebrates/artemia.html, retrieved February 13, 2011.
Heartworms are a parasitic nematode of mammals and have first been observed in Italy in 1626 (3). Later the parasite was introduced to the Americas by European immigrants leading to the earliest recorded heartworm finding in the United States in 1847 published in The Western Journal of Medicine and Surgery (3,5). In 1995 the intracellular Gram-negative bacterial endosymbiont Wolbachia, belonging to the order Rickettsiales, was identified to reside in the heartworms tissue (4).Today heartworm infections have been reported in all states except Alaska and the number of incidents are increasing at an alarming rate (5).
Mao Dun, author of "Spring Silkworms", was a twentieth century Chinese novelist, critic, organizer, editor, and advocate for Chinese Communism. According to David Wang, Mao Dun was one of the most versatile Chinese literati among the May Fourth generation. Mao Dun was an advocate and practitioner of European naturalism. Motivated by history and politics, Mao Dun has introduced western literary ideas to China in his novels. As a left wing writer Mao Dun focuses on the peasant's point of view and relies on his depiction of reality to evoke change. A good example of this style of writing is the story "Spring Silkworms".
The battle between sexual and asexual reproduction is a competition that has been ongoing for millions of years. Somewhere along the way due to its higher level of genetic variation, sexual reproduction was able to overcome the two fold advantage of asexual reproduction, and now dominates reproduction in organisms. However, some types of organisms such as worms and corals have acquired the ability to reproduce both sexually and asexually. The purpose of this paper is to explore the differences in asexual and sexual reproduction both from a biological and an evolutionary standpoint and to explain why evolution has made it possible for soft corals to reproduce both sexually and asexually.
The earthworm digestive system is one of the simplest digestive systems compared to the frog or a human. The digestive system is section off into certain parts and each part has a certain function in the digestive process. The earthworm’s digestive system consists of the pharynx, the esophagus, crop, the intestine, and the gizzard. Each organ has a specific contribution to the digestion in an earthworm. The food, which is usually soil, passes through the mouth and is swallowed into the digestive system through the pharynx. Then, the soil passes down the esophagus which has enzymes that help to rid the earthworm’s body of extra calcium that...
The eye is an extremely diverse organ, ranging in complexity across and within animal phyla. Here, a comparative approach is taken to outlining the diversity of the eye forms within vertebrates and invertebrates. The eye morphology of a variety of organisms was examined. Eye function, and placement on the body was also considered. Here, variation in eye form is discussed in relation to the environment the organism is adapted to. It is shown that an organisms eye morphology functions optimally for the ecological niche it occupies. Evolutionary analysis is used to account for the emergence of the different eyes. Convergent evolution is used to justify the similarities in eye types seen in organisms of different species. This analysis begins with the simplest of eye forms composes of single cells, present in the zooplankton larvae. Such primitive forms are identified in mollucs, annelids, cnidarians, and are then compared to more advanced eye forms contain lenses. This comparative approach provides a breadth of examples of vertebrates and invertebrates, making visible, the diversity of eye morphology within the animal kingdom.
Fertilization occurs when the sperm from the male and the ovum from the female combine to create a zygote. The zygote will then go through a gestational period which consists of three different stages. The first stage is the germinal stage and it starts from conception and ends at two weeks, during this stage the zygote divides and becomes much more complex and then implants into the uterine wall where it will then go on to the second stage. The second stage is the embryonic stage, this stage starts at two weeks and ends at eight weeks. During the embryonic stage the zygote has become an embryo and the organs and major body systems form and develop very rapidly. This is one of the most critical periods for physical development, the embryo is very sensitive to many different types of influences. The third and final stage of the gestational period is the fetal stage, this stage starts at eight weeks and ends at birth. During this stage the fetus grows approximately twenty times its previous length and the organs and body systems continue to develop becoming more complex and becomes ready for survival outside of the womb. Children grow the fastest during the first three years of their life, and they will never grow this rapidly again. As the child grows the child will go through various stages of physical development such as puberty and sexual maturity. After the first few