c) It provides water for me forlow d) it stops the feter from deging our 20. Depending apon the function immersing the mother and that of the ombryo the planette in turned a) Cotyledonary Placenta, Zonary Placente and diffuse b) Morula.blastoderm trophobles Blastodise c) Blastocyst frophoblast gastride, blautodise d)Syndesmochorial Hemochorial Endotheliochorial Spitheliochorial c) Mesoderm ectoderm.endodern, demis 21.When the entire surface of the allantochorion us insolbed in formation of the placental i a) Hemochorial b) Discoidal Placenta d)Endotheliochorial c) mone of the albone 22. The type of placenta where a single placenta is formed and it is a disc shaped, and thus referred to as a) Zonary Placenta b) Discoidal Placenta c) Cotyledomary Placenta d)Syndesmochorial Endotheliochorial 23.The primates placenta in which the endothelial continuity of the maternal blood vessels is disrupted and where the chorion is actually bached in the maternal blood is a) Hemochorial b) Discoidal Placenta c) Cotyledomary d)Endotheliochorial c) diffuse 24. The animal egg is swept through the oviduct toward the uterus by a) The beating of the egg's cilia. b) The beating of the egg's flagella.

20. The correct answer is d) Syndesmochorial, Hemochorial, Endotheliochorial, Spitheliochorial. These terms refer to different types of placentation in mammals, where the placenta attaches to the uterine wall in various ways.<br /><br />21. The correct answer is a) Hemochorial. Hemochorial placentation is when the entire surface of the allantochorion is involved in the formation of the placenta, allowing for maximum nutrient and gas exchange between the mother and the developing embryo.<br /><br />22. The correct answer is b) Discoidal Placenta. A discoidal placenta is a type of placenta where a single, disc-shaped placenta is formed. This type of placenta is typically found in species with a relatively small number of offspring, such as monotremes (e.g., platypus and echidnas).<br /><br />23. The correct answer is d) Endotheliochorial. In an endotheliochorial placenta, the chorion is actually bathed in the maternal blood, as the endothelium of the maternal blood vessels remains continuous with the chorionic villi. This type of placentation is characteristic of primates, including humans.<br /><br />24. The correct answer is a) The beating of the egg's cilia. The egg is swept through the oviduct toward the uterus by the coordinated beating of the cilia lining the oviduct. This ciliary action creates a current that propels the egg toward the uterus.