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

Microbiology quiz question, Each of the following are true of antimicrobial...

Each of the following are true of antimicrobial therapeutic drugs except A. Non-toxic to host B. Easily broken down by host C. Easily administered D. Limited capacity to elicit

What is oxidative phosphorylation, What is oxidative phosphorylation? O...

What is oxidative phosphorylation? Oxidative phosphorylation is  the process by which ADP is phosphorylated by Pi  to ATP  in  the  respiratory chain.

Explain entecavir, Explain Entecavir  Entecavir  (Baraclude) taken ora...

Explain Entecavir  Entecavir  (Baraclude) taken orally once a day as monotherapy appears to be superior to lamivudine for patients with chronic HBV infection, but susceptibili

Describe what are non degradable pollutants, Question : (a) Briefly de...

Question : (a) Briefly describe what are non degradable pollutants? (b) What do you meant by ichthyosarcotoxic fishes and give two examples of ichthyosarcotoxic fish poiso

Explain factors influencing lipid oxidation, Factors Influencing Lipid Oxid...

Factors Influencing Lipid Oxidation  Food lipids contain a variety of fatty acids that differ in chemical and physical properties and also in their susceptibility to oxidation.

What do carbon chains common with a skeletal system, What do carbon chains ...

What do carbon chains have in common with a skeletal system?

Explain nutritional and functional role of phosphates, Minerals :- Phosphat...

Minerals :- Phosphates Food Source      Ubiquitous, animal products tend to be good sources Nutritional Functional role Essential nutrient: Deficiency is rare due

Define estimation of blood thiamin levels - thiamin status, Define Estimati...

Define Estimation of Blood Thiamin Levels - Thiamin Status? The levels of free thiamin and its phosphoesters in whole blood and erythrocytes are measured using high- performanc

Define sodium, Define Sodium, Potassium and Chloride - Minerals? Claude...

Define Sodium, Potassium and Chloride - Minerals? Claude Bernard was the first to draw attention to the internal environment (milieu interior), referring to the extracellular f

Define advantages and disadvantages of swab method, Define Advantages and D...

Define Advantages and Disadvantages of Swab Method? Advantages of Swab Method 1. Suitable for flexible, uneven and heavily contaminated surfaces. 2. Rapid, simple and ine

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