Question

Bryophytes are dependent on water, because

• A. water is essential for their vegetative propagation
• B. the sperms can easily reach upto egg in the archegonium
• C. archegonium has to remain filled with water for fertilization
• D. water is essential for fertilization for their homosporous nature

Answer 1

The Correct Option is B

Bryophytes are a group of non-vascular plants that include mosses, liverworts, and hornworts. They are primarily terrestrial but require a moist environment because of their dependency on water for sexual reproduction. The correct answer to why bryophytes are dependent on water is:

the sperms can easily reach up to egg in the archegonium

Let's delve into the reasoning and rules out other options:

1. Requirement for Water in Sperm Transfer:

   Bryophyte sperm are flagellated and motile, needing water to swim towards the egg, which is located in the archegonium. The presence of a thin film of water facilitates this movement, allowing sperm to reach and fertilize the egg. Thus, bryophytes are called 'water-loving' organisms. This is the reason that they are often found in moist environments.

2. Rejection of Other Options:

   • Vegetative Propagation: While water might play a role in spreading vegetative portions of the plant, it is not the primary reason for their overall dependence on water.

   • Filled Archegonium for Fertilization: This option is partly true, but the primary function of water is not to fill the archegonium but to allow motile sperm to reach the egg.

   • Homosporous Nature: Bryophytes can be homosporous, but this refers to their spore production and not the dependency on water for fertilization.

In conclusion, the dependency of bryophytes on water is mainly due to the need for sperm motility to reach the egg in the archegonium, ensuring successful fertilization. Understanding the life cycle of bryophytes highlights the critical role water plays in their reproductive process.