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

What percentage of the offspring will be tall, Tall (T) plants are dominant...

Tall (T) plants are dominant and short (t) plants are recessive. Two heterozygous tall plants are crossed. What percentage of the offspring will be tall?

Define self monitoring of blood glucose, Q. Define Self Monitoring of Blood...

Q. Define Self Monitoring of Blood Glucose? Self Monitoring of Blood Glucose (SMBG): A patient can monitor the glucose level at home by self using the glucometer for checking t

How many g of h2so4 does contain, How many g of H2SO4 does  600 ml of a 1.2...

How many g of H2SO4 does  600 ml of a 1.2 M solution of H2SO4 contain? Please show all steps.

Explain light in cell metabolism, Explain Light in cell Metabolism? Ene...

Explain Light in cell Metabolism? Energy for almost all organisms on earth is derived directly or indirectly from light energy produced by the sun. Sunlight consists of energy

Why are euglenas involved in polemics, Why are euglenas involved in polemic...

Why are euglenas involved in polemics related to their taxonomic classification? Euglenas are included in taxonomic polemics because they tend to be classified sometimes as pro

What are the hormones secreted by the neurohypophysis, What are the hormone...

What are the hormones secreted by the neurohypophysis? What are their respective functions? The neurohypophysis secretes oxytocin and the antidiuretic hormone (ADH). Oxytoci

What is hansen disease, What is Hansen's disease (etiological agent, mode o...

What is Hansen's disease (etiological agent, mode of transmission, clinical manifestations and prevention)? The etiological agent of Hansen's disease is bacteria known as Mycob

Protozoa, Advantages and disadvantages of protozoa

Advantages and disadvantages of protozoa

State bioinert materials, State Bioinert materials Bioinert materials a...

State Bioinert materials Bioinert materials are chemically inert in the body and exhibit minimal chemical interaction with adjacent tissue such as titanium and alumina (Al 2 O

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