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

What is a biologic failure, What is A biologic Failure A biologic Fail...

What is A biologic Failure A biologic Failure can be defined as the inadequacy of the host to establish or to maintain osseointegration. The inability to establish osseoint

What is the estimated percentage of water in the human body, Q. What is the...

Q. What is the estimated percentage (in mass) of water in the human body? Is this percentage expected to be larger in the adult or in the old individual? Approximately 65% of t

An a=t mispairing leads to an a=c substitution, An A=T mispairing leads to ...

An A=T mispairing leads to an A=C substitution. The other DNA helix will contain a(n) __ pair. a. A=C b. A=T c. G=C d. B=Q e. T=T Can you also explain it please so if I'm ask

Type specimen of class enteropneusta, Q. Type specimen of class enteropneus...

Q. Type specimen of class enteropneusta? Examine the specimen and note the following features: 1. Balanoglossus has a soft, elongated, worm-like body which has a ciliated surf

Can you illustrate trna anticodon, Q. If a tRNA anticodon is CAA what is it...

Q. If a tRNA anticodon is CAA what is its corresponding mRNA codon? For the genetic code which amino acid does this codon codify? According to the C-G, A-U rule, the correspond

What compound composes most of the cell membrane, What compound composes mo...

What compound composes most of the cell membrane? How is this compound suited to the function of the membrane? Phospholipid composes most of the cell membrane. The hydrophob

Define the carbohydrate and fat required for elderly, Define the Carbohydra...

Define the Carbohydrate and Fat required for elderly? Carbohydrate: It is usually recommended that approximately 55en% (percent of  energy) be provided from carbohydrate food

Diseases, what are the sources of infection (human, animal and non-living r...

what are the sources of infection (human, animal and non-living reservoirs), the routes of transmission (way in which the infection spreads) and different ways in which micro-organ

Ultrasonic removal of gutta percha, Ultrasonic removal of Gutta percha: ...

Ultrasonic removal of Gutta percha: -the piezoelestic ultrasonic system. - As the instruments is energized; producing heat to themosoften gutta-percha. - Float gutta-perc

Why is carbon monoxide toxic for humans, Q. Why is carbon monoxide toxic fo...

Q. Why is carbon monoxide toxic for humans? Hemoglobin "likes" carbon monoxide (CO) much more than it likes oxygen. When there is carbon monoxide in the inhaled air it binds to

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