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Legal Relevance
editIt would be useful to add information regarding legal issues arising from the increased practice of freezing embryos. For example, the legal ramifications in the event of divorce with respect to allocation of embryos is an increasingly popular topic as more individuals have turned to this form of assisted reproductive technology in recent years.
Ahowel10 (talk) 16:41, 8 September 2021 (UTC)Andi Howell
need to include the latest research on the ‘synthetic embryos’ and mechanical womb
edithere's some sources news about synthetic embryo https://www.theguardian.com/science/2022/aug/03/scientists-create-worlds-first-synthetic-embryos paper: https://www.cell.com/cell/fulltext/S0092-8674(22)00981-3 paper on mechanical womb that enabled natural mouse embryos to grow outside the uterus https://www.nature.com/articles/s41586-021-03416-3 Kaveinthran (talk) 08:12, 4 August 2022 (UTC)
Etymology
editThe present section appears to be substantially Original Research, although research from sources. The OED disagrees with it in detail, seeing a confusion of two distinct High Medieval Latin forms, one related to βρύον moss. Neither of them are in Latin -us, -um.
If I see no objection the next time I come by, I will take it out. Septentrionalis PMAnderson 21:24, 26 August 2022 (UTC)
gametogenesis
editmental Biology 2022-1
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Developmental Biology 2022-1
Course: Biochemistry (Bsc221)
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University: Masinde Muliro University of Science and Technology
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Document continues below Discover more from: Biochemistry Bsc221 Masinde Muliro University of Science and Technology 38 Documents Go to course 5 Nutrition in plants and animals questions Nutrition in plants and animals questions 100% (3) 56 STA 141 Topic 1 Introd to Statistics STA 141 Topic 1 Introd to Statistics 100% (2) 47 3 - Notes 3 - Notes Biochemistry 100% (1) 69 Sbl 11 laboratory safety notes 2023 Sbl 11 laboratory safety notes 2023 Biochemistry 100% (1) 48 BSc-Zoology-04Sem-Dr. Desh Deepak Chaudhary-Animal Behaviour BSc-Zoology-04Sem-Dr. Desh Deepak Chaudhary-Animal Behaviour Biochemistry 100% (1) 49 SEED Inspection Manual Harmonized- Final- Wachira comments SEED Inspection Manual Harmonized- Final- Wachira comments Biochemistry None Cheplau (talk) 14:33, 31 October 2024 (UTC)
cleavage
editCleavage refers to a series of highly synchronous divisions of a zygote into cells called blastomeres. It occurs in eggs activated by fertilization or parthenogenetic agents. Cleavages follow one another so rapidly that there is little opportunity for daughter cells to grow before they divide again. Consequently, the size of blastomeres diminishes progressively, although many times unequally during cleavage. By contrast the nucleus of each daughter cell enlarges following each cleavage with the result with the result that the ratio of the volume of the nucleus to the volume of cytoplasm progressively increases. The cleavage period is said by some embryologists to terminate when the nucleuoplasmic ratios of various blastomeres attain value characteristic of adult tissue. Characteristics of cleavage a) The unicellular fertilized egg is transformed by consecutive mitotic divisions into a multicellular complex. b) No growth occurs c) The general shape of the embryo does not change, except formation of an interior cavity called blastocoele d) The constituent parts of the cytoplasm of the egg are not displaced to any great extent and remain in the same position as in the egg at the beginning of cleavage e) The ratio of nucleus to cytoplasm, very low at the beginning of cleavage is at the end brought to the level found in the somatic cell of the adult. Types of cleavage The pattern of cleavage exhibited by a particular species is affected by 2 main factors:- i. The amount of yolk present in the egg Large amounts of yolk tend to displace the mitotic apparatus to an off the center position and inhibit the progress of the cleavage furrow. The quantity of yolk will differ from one animal group to the other. ii. Orientation of the mitotic apparatus within the non-yolky region of the egg When the mitotic apparatus is perpendicular or parallel with respect to the animal-vegetal axis, cleavage is regular. Most animals exhibit regular cleavage. When the mitotic apparatus is tilted with respect to the animal-vegetal axis, cleavage is oblique or spiral. Spiral cleavage occurs in flatworms, annelids and non cephalopod molluscs. Cleavage can be broadly classified into two types: - Holoblastic cleavage where the entire egg undergoes division and Meroblastic cleavage where only part of the egg undergoes cleavage. Holoblastic cleavage [holo-whole, blastos-germ] This is where the entire egg undergoes division. The cleavage furrow extends completely through the egg. Holoblastic cleavage can be equal i.e. cells resulting from the cleavage are of an equal size as in isolecithal eggs or holoblastic unequal where the entire egg undergoes division but the resulting cells are of unequal size and thus two types of cells are formed: small yolk free micromeres and large yolky megameres on the vegetal pole. It occurs in mesolecith Cheplau (talk) 14:39, 31 October 2024 (UTC)