Types of fertilization, Biology

TYPES OF FERTILIZATION -

On the basis of site of fertilization, it is of two types - 1. External fertilization        2. Internal fertilization

1.       EXTERNAL FERTILIZATION -

When fertilization take place outside the body, mainly it occurs in water.

Both the sperm & ova are released simultaneously in the water.

External fertilization is two types -

(i) External fertilization in fresh water - Eg. fishes, amphibians & aquatic invertebrate animal.

(ii) External fertilization in sea water - This types of fertilization take place in lower animals.

2.       INTERNAL FERTILIZATION -

It take place generally oviduct of female. In urodela the internal fertilization take place in the lower part of the oviduct.

In Salamendra, reptiles, birds & mammals the internal fertilization take place in upper part of the oviduct.

In Ovo-viviparus & viviparus animals always internal fertilization take place.

In oviparous animals fertilization may be external or internal.

On the basis of sperm penetration, fertilization is of 2 types -

1.      MONOSPERMY -

When one sperm enter into an ovum is called as monospermy. It is most common type of fertilization.

2.      POLYSPERMY -

When two or more sperms enter into an ovum. It is 2 type -

(i) Pathological polyspermy - In this more than one sperm enter into immature and highly mature ova and all sperm participate to amphimixis. The resulting embryo is dead.

(ii) Physiologicla polyspermy -

In this many sperm are enter into the ova but only one sperm participate to amphimixis.

Eg. Molluscs, Insect, Elasmobranchi, Urodela, Reptiles, Birds & Rabbit. Dead sperms are called merozoites.

Posted Date: 10/3/2012 8:22:41 AM | Location : United States







Related Discussions:- Types of fertilization, Assignment Help, Ask Question on Types of fertilization, Get Answer, Expert's Help, Types of fertilization Discussions

Write discussion on Types of fertilization
Your posts are moderated
Related Questions
Describe Arteriovenous Continuous Murmur? Arteriovenous Continuous Murmur :  These can be congenital as in coronary artery fistula entering RA/RV/PA, sinus of valsalva to rig

Define the effects of Deficiency of Calcium in the Body? If there is a continued inadequate intake or poor intestinal absorption of calcium, plasma calcium concentrations will

Q. Write the meaning of Polyuria? Increased Urine (Polyuria): When sugar is increased in the blood it is filtered from the body along with the water. This is the reason for fre

Which two gases are exchanged when living organisms breathe? Oxygen and carbon dioxide are the gases exchanged when living organisms breathe.

Explain the Source of Energy - Growth of Microorganism? Constant supply of energy is required to carry out cellular activities, like biosynthesis and degradation of macromolecu

The doctor ordered 3 teaspoons of Basaljel suspension in water or juice. How many cc of Basaljel (aluminum carbonate) should the nurse place in the medicine cup?

Handling : You can reduce direct contact with microorganisms by careful handling and by wearing protective clothing such as rubber gloves, mask, lab coat, etc. Even if you entirel

Define Sterol Regulatory Element Binding Proteins (SREBPS)? These belong to a general family of transcription factors. They are synthesized as membrane embedded proteins in res

Define Bone growth and development calcification of osteoid tissue? Vitamin D participates in metabolic processes associated with bone growth and development. It is involved i

DIFFERENCES BETWEEN MITOSIS AND MEIOSIS    EVENTS  MITOSIS  MEIOSIS  Occurrence  In all the body cells including