Flatworms (Platyhelminthes) are phylum of unsegmented, soft, flat invertebrates.
Flatworms have no body cavity which is why they are flat. The advantage of a flat body is facilitated respiration and circulation. Flatworms do not have respiration and circulation system. But, oxygen diffuses across the skin and reach all parts of the body thanks to a flattened shape. Also, it is easy to hide from predators because they can get almost everywhere thanks to the body shape.
<span>Help???? Can some answer this</span>
Stars are the spherical object according to Aristotle's geocentric model.
<h3>Aristotle's geocentric model</h3>
Aristotle's model of the universe was also geocentric in which the Sun, Moon, planets, and stars all orbiting the Earth and present inside of Eudoxus' spheres and also revolves around the planet earth.
Aristotle believed in a geocentric Universe and that the planets and stars were perfect spheres, but the Earth itself was not a perfect sphere so we can conclude that Stars are the spherical object according to Aristotle's geocentric model.
Learn more about stars here: brainly.com/question/13106554
Amniocentesis or amniotic fluid test or AFT refers to the prenatal diagnosis of chromosomal abnormalities and fetal infections. It is performed after 16 weeks of pregnancy. The fetal DNA from a small amount of cells from the amniotic fluid of the amniotic sac is sampled for genetic abnormalities by inserting a needle and extracting it. The fluid contains cells that are sloughed off by the fetus. They are separated from the amniotic fluid, grown in a culture and then microscopically examined for genetic and chromosomal abnormalities. The test is a reliable indicator of chromosomal abnormalities such as Down’s syndrome, spina bifida, muscular dystrophy, rh diseasetrisomy 13, trisomy 18, fragile X, Tay-Sachs disease, Hunter's syndrome and other metabolic disorders.
<span>Crayfish and Annelids both have segments and most of them are aquatic.Crayfish live in freshwater, they have a joined head and thorax, or midsection, and segmented body. While a basic annelid form consists of multiple segments which each segment has the same set of organs. They survive in aquatic habitats or in damp soil.
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