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Showing posts from April, 2021

Comparison between tract and nerve

  Comparison between tract and nerve Nerve Nerve contain bundle of axons (nerve fibers) in the peripheral nervous system (PNS) that transmits signals between the central nervous system (CNS) and other parts of the body. It is the most important part of peripheral nervous system Location: Peripheral nervous system. Structure: Made of axons, connective tissue layers (endoneurium: axon is surrounded by it , perineurium: bundle of axons are surrounded by it, epineurium: whole nerve trunk is surrounded by it), and blood vessels. It gets myelination by Schwann cell   Function: Carries sensory signals to the CNS (afferent) from peripheral part of body or motor signals carry from from the CNS (efferent) to target organs like skeletal muscle, cardiac muscle, smooth muscle or glands Example: Sciatic nerve, median nerve, except optic nerve (though optic nerve is technically part of CNS in develop...

Difference between different cells of oogenesis

 Difference between different cells of oogenesis  Cell type ploidy/chromosomes chromatids Process Time of completion Oogonium diploid/46(2N) 2C Oocytogenesis (mitosis) Third trimester primary oocyte diploid/46(2N) 4C Ootidogenesis (meiosis I) (Folliculogenesis) Dictyate in prophase I for up to 50 years secondary oocyte haploid/23(1N) 2C Ootidogenesis (meiosis II) Halted in metaphase II until fertilization Ootid haploid/23(1N) 1C Ootidogenesis (meiosis II) Minutes after fertilization Ovum haploid/23(1N) 1C

Difference between different cells of spermatogenesis

 Difference between different cells of spermatogenesis Cell type ploidy/chromosomes in human DNA copy number/chromatids in human Process entered by cell spermatogonium diploid (2N) / 46 2C / 46 spermatocytogenesis ( mitosis ) primary spermatocyte diploid (2N) / 46 4C / 2x46 spermatidogenesis (meiosis I) two secondary spermatocytes haploid (N) / 23 2C / 2x23 spermatidogenesi (meiosis II) four spermatids haploid (N) / 23 C / 23 spermiogenesis four functional spermatozoids haploid (N) / 23 C / 23 spermiation  

Comparison between Meiosis in Males and Females

  Comparison between Meiosis in Males and Females   Topics Meiosis in Males Meiosis in Females Definition It is a continuous process which starts from puberty and remains throughout life. The process results into production of millions of spermatozoa daily. This process may take over 40 years from start to finish. Only a few oocytes reaches upto the final stages, as most of them are lost before birth. Occurs at Seminiferous tubules of the testicles Oogonia (ovary) Number of haploid cells Equal number of haploid cells(4 gametes) A single enlarged haploid cell Time Completed in days or weeks Delayed for months or years Cell Division Symmetric Asymmetric Start time Begins around puberty Begins before birth Efficiency of Chrom...