Antipodal cells

Definition

Antipodal cells are specialized cells located at the opposite end of the embryo sac in flowering plants, specifically within the female gametophyte structure. They are part of the seven-celled structure that forms after double fertilization and play a role in the development of the seed, even though they are often considered to have a limited function compared to other cells like the egg or synergids. Their presence reflects the complex reproductive development that is essential for successful fertilization and seed formation.

5 Must Know Facts For Your Next Test

1. Antipodal cells typically consist of three cells located at the chalazal end of the embryo sac in angiosperms.
2. These cells usually degenerate after fertilization and do not contribute directly to the development of the embryo or endosperm.
3. The main function of antipodal cells is still debated, but they may play a role in nutrient transfer during early seed development.
4. Antipodal cells are formed during the process of megasporogenesis and megagametogenesis, which involves meiosis and mitotic divisions.
5. Their formation is essential for maintaining the proper structure of the embryo sac, influencing the overall reproductive success of flowering plants.

Review Questions

• How do antipodal cells relate to the overall structure and function of the embryo sac in flowering plants?
  • Antipodal cells are an integral part of the seven-celled structure of the embryo sac, located at the opposite end from the egg and synergids. While their direct function is limited, their presence contributes to maintaining the structural integrity of the embryo sac, which is crucial for successful fertilization and subsequent seed development. Understanding their role helps clarify how different components of the gametophyte work together in plant reproduction.
• Discuss the differences between antipodal cells and synergids regarding their roles in plant reproduction.
  • Antipodal cells and synergids serve distinct functions within the embryo sac. Synergids are located adjacent to the egg cell and actively participate in guiding pollen tube growth towards the ovule during fertilization. In contrast, antipodal cells are positioned at the opposite end and generally do not take part in fertilization but may assist indirectly by contributing to nutrient transfer. This differentiation highlights how various cell types within the gametophyte support different aspects of reproductive success in flowering plants.
• Evaluate the significance of antipodal cells within the context of double fertilization and their impact on seed development.
  • Antipodal cells play a seemingly minor role in double fertilization compared to other components like egg cells and polar nuclei. However, their presence is vital for forming a complete embryo sac structure, which is necessary for successful fertilization. While they typically degenerate post-fertilization, understanding their contribution allows for a deeper appreciation of how each cell type supports not only fertilization but also influences subsequent seed development. The study of these interactions sheds light on evolutionary adaptations in flowering plants to enhance reproductive efficiency.

Related terms

embryo sac:

The female gametophyte in flowering plants, typically containing seven cells, including the egg cell, synergids, and antipodal cells.

synergids: Two specialized cells located near the egg cell in the embryo sac that help facilitate fertilization by guiding pollen tube growth.

double fertilization:

A unique process in flowering plants where one sperm cell fertilizes the egg cell while another sperm cell fuses with two polar nuclei to form triploid tissue, leading to seed development.