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

Gateway reaction-entry clone and destination vector, (1) From the above gat...

(1) From the above gateway reaction (entry clone and destination vector); (i) which plasmid will be selected for when transformed into E.coli (A or B) and why? (ii) which an

Describe the features common in ventricular outflow, Describe the Features ...

Describe the Features common in ventricular outflow obstruction ? An ejection systolic murmur (ESM) due turbulent flow of blood through the obstruction. Hypertrophy of the cham

Under which forms is the trypanosoma cruzi found, Under which forms is the ...

Under which forms is the Trypanosoma cruzi found in its hosts? In the definitive hosts as well as in triatomine bugs (middle hosts) the protozoan that causes Chagas' disease ch

Why plants need to do exchange gases with the environment, Why plants need ...

Why plants need to do exchange gases with the environment? The Plants need to do gas exchange because they create aerobic cellular respiration (like animals) and they need to r

Urgency, Overcoming these difficulties is urgent. New instrumentation and ...

Overcoming these difficulties is urgent. New instrumentation and measurement process, coupled with a developing computational infrastructure, give both a flood of data and the pro

What is genes duplication, What is genes Duplication ? Duplication of g...

What is genes Duplication ? Duplication of genes can happen when a portion of a chromosome breaks off and attaches itself to the end of its homologous chromosome, as seen below

To observe yeast plants, To observe yeast plants Borrow a microscope fr...

To observe yeast plants Borrow a microscope from a college, a high school, a doctor or a hospital. Place a some drops of the sugar solution which having yeast on a glass slide

Are alleles segregate during meosis, Gregor mendel was an austrain augustia...

Gregor mendel was an austrain augustianian monk; his work most notably showed that. a. Alleles segregate during meosis b. Capital alleles are dominant c. The genetic material is pa

What is the difference between dna and rna, Concerning their biological fun...

Concerning their biological function what is the difference between DNA and RNA? DNA is the source of information for RNA production (transcription) and therefore for protein s

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