Mating and fertilisation, Biology

Assignment Help:

Mating and Fertilisation

In all animals sperms are motile and have to move and seek the eggs to fertilise them. For this an aqueous environment is necessary. This need of a liquid medium has led to two basic mating patterns.

1. External fertilisation - mating partners come in close proximity in water and concurrently shed their eggs and sperms in water.

2 Internal fertilisation - mating partners come into physical contact and copulate, in which the male transfers the sperms directly into the reproductive ducts of the female. The ova coming down the ducts obtain fertilized. Internal fertilisation is characteristic of terrestrial animals, but as well occurs in several aquatic forms. Internal fertilisation usually leads to development of an intromittent organ or penis in the male partner. A range of such copulatory organs are found in non-chordates, such as like dates there are spermathecae for storing sperms received during mating. As the eggs pass down the ducts sperms are released from the spermathaca to feitilise them. Honey bee queen mates just one time when it receives enough sperms to fertilise the many thousands of eggs she is going to lay in 4-5 years of reproductive life.


Related Discussions:- Mating and fertilisation

Antioxidants and flavanoids requirement in dyslipidemia, Q. Antioxidants an...

Q. Antioxidants and Flavanoids requirement in dyslipidemia? Antioxidants and Flavanoids: You must have already read about different antioxidants present in our foods. The body

What food items include in full liquid diet, What food items  include in f...

What food items  include in full liquid diet -  Soups and broths -  Cereal porridges (refined cereals) -  Milk and milk beverages, yoghurt - Coffee, tea, fruit  juices

Explain the metabolic pathways in the cornea, Explain the metabolic pathway...

Explain the metabolic pathways in the cornea. Metabolic Pathways: a. 88 per cent of glucose is utilized through glycolysis. b. Only 12 per cent of glucose utilized by

Define source of electrons - growth of microorganism, Define Source of Elec...

Define Source of Electrons - Growth of Microorganism? Depending upon the source of electrons used by microorganisms, these are known as - a) Lithotrophs (rock eaters) - use

What is retrograde peri-implantitis, Retrograde Peri-Implantitis It has...

Retrograde Peri-Implantitis It has been described by Misch as implant failure probably due to bone microfractures caused by premature implant loading or overloading, other form

Conductometry, conductometry and its uses in biology

conductometry and its uses in biology

What is an example of evolutionary novelty, Compared to amphibians what is ...

Compared to amphibians what is an example of evolutionary novelty present in beings of the class Reptilia against the loss of water through the skin? The reptile skin is kerat

Define ascorbic acid content of white blood cells, Define Ascorbic acid con...

Define Ascorbic acid content of white blood cells? The ascorbic acid content of white blood cells and platelets is a good index of the tissue levels of ascorbic acid. The level

Illustrate sequential phases of the cell cycle, Q. How does the quantity of...

Q. How does the quantity of genetic material differ within the cell during the sequential phases of the cell cycle? The first period of the first phase interphase of the cell c

Work sheet, When the Balance Sheet column totals don't agree on the first a...

When the Balance Sheet column totals don't agree on the first attempt work backward through the process used in preparing the work sheet exclusively take the following steps until

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