Barriers to fertilisation, Biology

Assignment Help:

Barriers to Fertilisation

Incompatibility can occur anywhere from pollination to syngamy and consequently obstructing fertilisation. The pollen fails to germinate or the pollen tube is inhibited to penetrate the stigma.

The progamic barriers to fertilisation may be on the stigma or in the style at any level from pollen germination to the discharge of male gamete in the vicinity of egg.

On the other hand, syngamy barriers include the inhibition of the entry of pollen tube to the ovary, ovule or within embryo sac. At the stage of pollination the barriers to fertilisation are of morphological and ecological types, whereas, at progamic phase and syngamy physiological barriers occur.


Related Discussions:- Barriers to fertilisation

Types of bone, TYPE S OF BONE - On the basis of its texture , a bone ...

TYPE S OF BONE - On the basis of its texture , a bone is of two types - Spongy or cancellous or tubercular bone and Compact or periosteal or dense bone.

Why binding motifs regulate gene expression, How do leucine zipper binding ...

How do leucine zipper binding motifs regulate gene expression?

Skeleton, biological significant of a skeleton

biological significant of a skeleton

Name the enzyme present in saliva, Name the enzyme present in saliva and sa...

Name the enzyme present in saliva and say what type of food it acts on.   The enzyme in saliva is salivary amylase and it acts on starch.

State the term - viral infections, State the term - Viral Infections A ...

State the term - Viral Infections A virus is an encapsulated aggregate of nucleic acid that may be made of either DNA or RNA. Some viruses, such as those causing poliomyelitis

What would its new ph be if the concentration of h3o ion, If a solution has...

If a solution has a pH of 7.5, what would its new pH be if the concentration of H 3 O ions in the solution were increased by 100 times? Explain your reasoning. As a tenfold inc

The transport system in earthworm., The transport system in earthworm ...

The transport system in earthworm The scientific name of earthworm is megascolex. It consists of hearts, blood vessel and blood. There are 8 pairs of hearts in the earthw

Define about the carbohydrates, Define about the Carbohydrates? In the ...

Define about the Carbohydrates? In the previous unit we have studied about the energy requirements. You now know that energy must be supplied regularly to individuals through t

Illustrate the major events of the final mitotic period, Q. What are the ma...

Q. What are the major events of the final mitotic period? The final mitotic phase is the telophase. In the telophase the following events occur decondensation of chromosomes ea

Define lipid-anchored proteins, A large number of integral proteins in euka...

A large number of integral proteins in eukaryotes do not traverse the membrane but are anchored in one or other leaflet of the bilayer through covalent attachment to a hydrocarbon

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