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

Gene mutatiorns, Gene or point mutations occur when the DNA sequence of a g...

Gene or point mutations occur when the DNA sequence of a gene is altered and the new nucleotide sequence is passed on to the offspring. This occurs either due to addition or deleti

TISSUES, HOW TO WRITE A CONCLUSION ON A ASSIGNMENT OF EPITHELIAL TISSUES

HOW TO WRITE A CONCLUSION ON A ASSIGNMENT OF EPITHELIAL TISSUES

Difference between anaerobic and aerobic beings, Q. What is the difference ...

Q. What is the difference between anaerobic and aerobic beings? Anaerobic organisms are those that live or can live under oxygen-lacking environments and Aerobic organisms are

Are there living beings without cells, Q Are there living beings without ce...

Q Are there living beings without cells? Viruses are considered the only living beings that do not have cells. Viruses are constituted by genetic material RNA or DNA enwrapped

Why is it not correct to assert that dna self-replicates, Why is it not cor...

Why is it not correct to assert that DNA self-replicates? DNA is not completely autonomous in its duplication process because the replication does not happen without enzymatic

Determine the structure of enzymes, Determine the Structure of Enzymes ...

Determine the Structure of Enzymes Since all enzymes are proteins, you will realize that knowledge of protein structure is clearly a pre-requisite to any understanding of enzym

Chronic exposure of cadmium, Q. Chronic exposure of Cadmium? An increa...

Q. Chronic exposure of Cadmium? An increase in the soil cadmium content due to soil pollution by industrial wastes, burning of coal, fossil fuels, sewage sludge, medical and

Animal Cells, what are the functions of cytoplasm ?

what are the functions of cytoplasm ?

Vitamins and minerals requirement in diabetes, Q. Vitamins and minerals req...

Q. Vitamins and minerals requirement in diabetes? The recommendation of vitamins and minerals is the same as for general population. However, lower levels of magnesium are ass

Molluscus, what are the ecological importance of molluscus

what are the ecological importance of molluscus

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