Skip to main content

Pollen tube entry (Types)

 Pollen tube entry (Types)

The entry of a pollen tube into the ovule is a crucial step in plant fertilization. This process involves the growth of a specialized structure, the pollen tube, which carries male gametes (sperm cells) towards the female gametes (egg cells) for fertilization. Let's explore the types of pollen tube entry in plants.

1. Porogamy:

  • In porogamy, the pollen tube enters the ovule through an opening called the micropyle.
  • The micropyle is a small pore in the integuments (protective layers) of the ovule.
  • This type of pollen tube entry is common in gymnosperms (non-flowering seed plants) and some angiosperms.

2. Chalazogamy:

  • In chalazogamy, the pollen tube enters the ovule through an opening at the opposite end of the ovule from the micropyle, known as the chalaza.
  • The chalaza is a basal part of the ovule where the integuments and nucellus (central part of the ovule containing the female gametophyte) join.
  • Chalazogamy is less common than porogamy and is observed in some angiosperms.

3. Mesogamy:

  • Mesogamy refers to the entry of the pollen tube into the ovule through the body of the ovule, between the micropyle and chalaza.
  • This type of pollen tube entry is relatively rare and occurs in specific plant species.

4. Ostiole:

  • In some cases, the pollen tube enters the ovule through an opening called the ostiole.
  • The ostiole is a specialized opening in the integuments of the ovule.
  • This mechanism is observed in certain plant species, contributing to the diversity of pollen tube entry strategies.

5. Direct Penetration:

  • In some gymnosperms, the pollen tube directly penetrates the integuments without the presence of a specific opening.
  • This direct penetration allows the pollen tube to reach the female gametes within the ovule.

6. Synergids and Pollen Tube Reception:

  • Within the female gametophyte, two specialized cells called synergids play a role in guiding the pollen tube to the egg cell.
  • The pollen tube navigates through the synergids, and one of them degenerates, creating a pathway for the pollen tube to reach the egg cell.
In Conclusion: 
    Pollen tube entry is a remarkable and finely tuned process that ensures the precise delivery of male gametes to the female gametes for fertilization. The diversity of entry mechanisms reflects the adaptive strategies of plants to their specific reproductive environments. As we explore these intricacies, remember the beauty and complexity of plant reproduction and the ingenious mechanisms that have evolved to ensure the continuity of plant life

Popular posts from this blog

Welcome to Let Me Explain (A Part of bionexts.in)

  Welcome to my Blogspot! Here, I explain various topics related to Bio-Medical Science with detailed class study notes. I trust it will be helpful for you. MISSION OF THE PROJECT My mission is to provide you Class Study Notes with a clear understanding of various Bio-Medical related topics, especially professional courses, using easy language. Don't worry; I'll also include other topics.  ☺️ CLICK ANY ONE OF THE SUBJECTS Immunology   Techno Professional Skill  Developmental Biology   Molecular Biology Cell Biology Genetical Engineering Biostatistics Bioinformatics Basic Acclimatization Skill Animal Biotechnology Medical Biotechnology Industrial Biotechnology Plant and Agricultural Biotechnology Research Methodology, IPR and Bioethics Are You Preparing For The GATE Examination Also! Click Here  Click Here   Are You Preparing For The UPSC Examination Also! Click Here Yes And Normal General Science Click Here And I'm going to explain to you the biology t...
Read more

Animal Biotechnology

On this page, you will find all topics related to Immunology! Here Every Major Topic Includes Sub-Major Topics. Find the topic you want to learn! Describe the basics of animal cell culture Introduction Definition, scope, and importance. Historical developments in animal biotechnology Basic requirement for animal cell culture Types of animal cells and their characteristics. Types of Culture Primary and secondary culture. Cell Cine & Maintenance and preservation of cell lines. history of animal cell culture Suspension culture ,  Cell cloning and hybridization ,  3D cultures ,  Scaling up & Growth factors.  Cell line and maintenance, viability test, cytotoxicity  Describe the cell culture and vaccine production Application of cell culture technology in the production of different vaccines and pharmaceutical proteins. Explain reproductive structures and artificial fertilization  Structure of sperm and ovum Cryopreservation of sperms and ova of...
Read more

MOLECULAR BIOLOGY

On this page, you will find all topics related to Immunology! Here Every Major Topic Includes Sub-Major Topics. Find the topic you want to learn! Genome Introduction to the Genome Prokaryotic and Eukaryotic Genome The Central Dogma of life C value paradox Genes are made of DNA Semi-conservative mode of DNA replication Cot Curve   Repetitive DNA sequences (satellite DNA, LINE, SINE etc) DNA melting and buoyant density Neucleosome Phasing DNA Replication and Recombination Replication initiation, elongation and termination in prokaryotes and eukaryotes DNA Replication (Explain) The Meselson-Stahl experiment Homologous Recombination at the molecular level The Holliday Model Double-stranded DNA repair model Removing of the DNA Primer / Flap Model DNA damage and Repair Mutation- Nonsense, missense and point mutations Intragenic and Intergenic suppression Frameshift Mutation Mutagens Transposition Transposable genetic elements in prokaryotes and eukaryotes Mechanism of transposition Role ...
Read more