Reproductive organs, Biology

Assignment Help:

Reproductive Organs

In several metazoans, gonads are well-defined. Testes and ovaries take up dissimilar shapes and anatomical dispositions. In cases of certain hermaphrodites similar reproductive tissue from one part may generate sperms and from another part the ova. In sponges, gonads are poorly defined. Sperms and eggs arise from choanocytes and archaeocytes that are transformed into spermatogonia. Sperms leave the sponge by water currents. They enter choanocytes of other sponges that transport the sperms to the egg. Thus fertilisation takes place in situ by the intervention of choanocytes. In cnidarians, testes and ovaries are distinct. In a number of species of Hydra both tests and ovaries may be formed in the same individual (monoecious, bisexual) or in dissimilar individuals but in most species they are found in different individuals (dioecious unisexual). A single ovum produced in the ovary is fertilized in situ by the sperms generally coming from a different hydra. In colonial cnidarians the gonads are formed on the medusae from interstitial cells below the radial canals. They are formed in the epidermis of sub-umbrella. Fertilization is generally external, in water.


Related Discussions:- Reproductive organs

Explain low birth weight infants (lbw), Explain Low birth weight infants (L...

Explain Low birth weight infants (LBW)? One-third of the babies born in US are of low birth weight, less than 2.5 kg. A LBW infant has an inadequate mineralized skeleton, poorl

Digestive system, Digestive system is one of eleven major body organ syste...

Digestive system is one of eleven major body organ systems in animals; it converts food from the external environment into the nutrient molecules which can be used and stored by t

What are the chemical requirements of implant materials, What are the Chemi...

What are the Chemical requirements of implant materials It must withstand corrosion by body fluids It should not have any direct or indirect negative effects on the surround

Metabolic cataysis, Metabolic Cataysis A large number  of chemical reac...

Metabolic Cataysis A large number  of chemical reaction  occur  every  moment in a cell  to keep it. In the living  state, The rate  if  chemical  reaction normally depends upo

What are the organic chemical groups, Q. What are the organic chemical grou...

Q. What are the organic chemical groups that describe carbohydrates? How are carbohydrates classified according to the presence of those groups? Carbohydrates are also known as

Sex-influenced traits, what are the examples of sex-influenced traits in hu...

what are the examples of sex-influenced traits in human?

Explain the wash technique used in sterilization process, Q. Explain the Wa...

Q. Explain the Wash Technique used in sterilization process? Use of artificial nails is contraindicated as is use of colored nail polish. Nails should be short enough to allow

Why in some cases is mitosis a synonym of reproduction, Why in some cases i...

Why in some cases is mitosis a synonym of reproduction? In some living beings asexual reproduction happens by many means: binary division, schizogony, budding, grafting, etc. I

Diseases, what diseases are caused by trypanosoma and entameoba histolytica...

what diseases are caused by trypanosoma and entameoba histolytica

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd