Formation of cocoon in earthworm, Biology

Assignment Help:

Formation of cocoon in earthworm:

In earthworm segments from 14 to 17 are swollen. Skin on these segments is thick and glandular. This is called clitellum.
When ovaries mature, the clitellum secretes a viscous substance in the form of a girdle.
This girdle hardens into a cocoon around the clitellum.
Earthworm wriggles out of the cocoon - cocoon moves anteriorly and the worm moves posteriorly.
Ova are discharged into the cocoon. When the cocoon moves over the spermathecae openings. Spermatozoa received from another animal are stored in the spermathecae are discharged into it.
The cocoon finally comes out of the body and both ends of cocoon get closed.
Fertilization takes place in cocoon. Since fertilization is taking place outside the body, it is external fertilization.
After about 8 to 10 weeks, young earthworms come out of the cocoon.

981_Formation of cocoon in earthworm.png

Related Discussions:- Formation of cocoon in earthworm

Zoonoses disease-staphylococcosis, Staphylococcosis The disease is caused ...

Staphylococcosis The disease is caused by the ingestion of preformed toxin released by Staphylococcus aureus. Epidemiology: Staphylococci grow in meat, dairy and bakery prod

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?

Plant reproduction, How does being able to reproduce asexually benefit the ...

How does being able to reproduce asexually benefit the plant?

Is nitrogen is important plant nutrients, Is nitrogen is important plant nu...

Is nitrogen is important plant nutrients Nitrogen is an important plant nutrient which is assimilated by most of the plants as nitrate and ammonium ions. Organic matter is the

Define regulation of water balance, Define Regulation of Water Balance? ...

Define Regulation of Water Balance? The input of water, as well as, its loss can be highly variable due to individual habits and environmental factors; in spite of this, the to

Percussive instruments-coronal disassembly devices, Percussive instruments ...

Percussive instruments -Crown and bridge remover CORONA flex I. Nitch -it's tip look like the curette and has hock -4 or 5 tips according to tooth position and accessib

What are the chemical bonds of the dna molecule, Q. What are the chemical b...

Q. What are the chemical bonds of the DNA molecule that are broken for replication process to occur? During the DNA replication process, hydrogen bonds between the nitrogen- co

Excretory system, Excretory organ of agama lizard

Excretory organ of agama lizard

Cell biology, what is the role of cholesterol in membrane fluidity?

what is the role of cholesterol in membrane fluidity?

Explain why methionine is the first amino acid, Explain why methionine is t...

Explain why methionine is the first amino acid in every growing polypeptide. The tRNA that pairs with the start codon on mRNA carries methionine. RNA having ribose; DNA contain

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages