Fertilization in earthworm, Biology

Assignment Help:

In earthworms, when the ovaries mature, the clitellum secretes a viscous substance in the form of a girdle. This girdle hardens in to a cocoon around the clitellum. The ova are discharged into cocoon. When this cocoon moves over the spermathecae openings, the sperms which are already collected from another worm and stored in the spermathecae are discharged into the cocoon. The cocoon finally, comes out of the body and fertilization takes place in the cocoon. As it is taking place outside the body, it is called as "external fertilization".


Related Discussions:- Fertilization in earthworm

Extractive use of biodiversity, Q. Extractive use of biodiversity? This...

Q. Extractive use of biodiversity? This includes direct use such as harvesting of wild plant species for use as food, fuel, fodder, fibre, shelter or medicine and hunting anima

Zoology, what is the term used for study of sponges,protozoa,colentreta,mol...

what is the term used for study of sponges,protozoa,colentreta,molusca,fish,aves,mammal

Explain pregnancy and diabetes mellitus, Explain Pregnancy and Diabetes Mel...

Explain Pregnancy and Diabetes Mellitus? During pregnancy, a woman who has pre-existing chronic disease requires special care, especially in case of mother's suffering from dia

Explain about atrial septal defect, Explain about Atrial Septal Defect (ASD...

Explain about Atrial Septal Defect (ASD) ? ASD occurs as an isolated anomaly in 5- 10 per cent of all CHDs. These communications occur in four sites i.e. in the central portion

Types of blastula, TYPES OF BLASTULA - Blastulas are of following type ...

TYPES OF BLASTULA - Blastulas are of following type -                    1 .       STEREOBLASTULA - The blastocoel is very small. It's blastomere are less in num

Illustrate meiotic division, Q. In which meiotic division does the separati...

Q. In which meiotic division does the separation of the homologous take place and what are the ploidies of the generated cells after the end of that process? The separation of

Why is genetic homozygosity dangerous, Why is genetic homozygosity dangerou...

Why is genetic homozygosity dangerous to a nearly extinct species? Genetic homozygosity leaves no variation for natural selection to act on. Thus, a new disease could wipe

Interventricular septum, It corresponds to the anterior and inferior interv...

It corresponds to the anterior and inferior interventricular grooves. Its right side is convex and bulges to the right ventricle. The septum has a posterior border which separates

Phototherapy unit, Phototherapy Unit Principle Photoisomerisat...

Phototherapy Unit Principle Photoisomerisation and photo-oxidation changes indirect bilirubin into water soluble substance. Operational Instruction Adjust

Explain elements of xylem in gymnosperms, The chief water conducting elemen...

The chief water conducting elements of xylem in gymnosperms are: 1. Vessels 2. Fibres 3. Transfusion tissue 4. Tracheids Tracheids

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