Concepts of Biology
Concepts of Biology

Author: Samantha Fowler

Publisher:

Published: 2023-05-12

Total Pages: 0

ISBN-13: 9781739015503

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Black & white print. Concepts of Biology is designed for the typical introductory biology course for nonmajors, covering standard scope and sequence requirements. The text includes interesting applications and conveys the major themes of biology, with content that is meaningful and easy to understand. The book is designed to demonstrate biology concepts and to promote scientific literacy.

Reproduction and Development in Annelida
Reproduction and Development in Annelida

Author: T. J. Pandian

Publisher: CRC Press

Published: 2019-01-30

Total Pages: 293

ISBN-13: 0429584482

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This book is a concise informative elucidation of all aspects of reproduction and development in annelids covering from arenicola to tubifex. Annelids flourish between 4,900 m depth to 2,000 m altitude; some of them occur in unusual habitats like hydrothermal vents and subterranean aquatic system (stigobionts). A few have no gut and acquire adequate nutrients through osmotrophism and/or engaging symbiotic microbes. In the absence of exoskeleton to escape predation, the 17,000 speciose annelids have explored bewildering modes of reproduction; not surprisingly, 42–47% of them are brooders. With 13,000 species, polychaetes are gonochores but some 207 species of them are hermaphrodites. Clitellates are all hermaphrodites; of them, 76 species are parthenogens, of which 56 are earthworms. Regenerative potency of annelids ranges from an organ to an entire worm from a single ‘seminal’ segment. The head, tail and both together can be regenerated 21, 42 and 20 times, respectively. However, the potency is limited to ~1% of polychaetes and Heterogamatic sex determination is reported to occur only in six polychaete species, although karyotype is known for 83 annelid species. In temperate polychaetes, a dozen neuroendocrines, arising mostly from the ‘brain’ regulates reproductive cycle. A complete chapter devoted to vermiculture, (i) recognizes the fast-growing candidate species, (ii) distinguishes 'layers' from 'brooders', (iii) indicates that the harvest of oligochaetes may reduce the input of nitrogenous fertilizer in the ricefield, and (iv) explores the scope for increasing wealth from waste.

Evolutionary Developmental Biology of Invertebrates 2
Evolutionary Developmental Biology of Invertebrates 2

Author: Andreas Wanninger

Publisher: Springer

Published: 2015-08-10

Total Pages: 291

ISBN-13: 3709118719

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This multi-author, six-volume work summarizes our current knowledge on the developmental biology of all major invertebrate animal phyla. The main aspects of cleavage, embryogenesis, organogenesis and gene expression are discussed in an evolutionary framework. Each chapter presents an in-depth yet concise overview of both classical and recent literature, supplemented by numerous color illustrations and micrographs of a given animal group. The largely taxon-based chapters are supplemented by essays on topical aspects relevant to modern-day EvoDevo research such as regeneration, embryos in the fossil record, homology in the age of genomics and the role of EvoDevo in the context of reconstructing evolutionary and phylogenetic scenarios. A list of open questions at the end of each chapter may serve as a source of inspiration for the next generation of EvoDevo scientists. Evolutionary Developmental Biology of Invertebrates is a must-have for any scientist, teacher or student interested in developmental and evolutionary biology as well as in general invertebrate zoology. This volume covers the animals that have a ciliated larva in their lifecycle (often grouped together as the Lophotrochozoa), as well as the Gnathifera and the Gastrotricha. The interrelationships of these taxa are poorly resolved and a broadly accepted, clade-defining autapomorphy has yet to be defined. Spiral cleavage is sometimes assumed to be the ancestral mode of cleavage of this grouping and therefore the clade is referred to as Spiralia by some authors, although others prefer to extend the term Lophotrochozoa to this entire assemblage. Aside from the taxon-based chapters, this volume includes a chapter that highlights similarities and differences in the processes that underlie regeneration and ontogeny, using the Platyhelminthes as a case study.