Hello, I'm Dr. Emily Carter, a botanist specializing in bryophyte biology. I've been studying liverworts for over 15 years and can help you understand their fascinating life cycle.

Liverworts, like other bryophytes, exhibit a unique life cycle called alternation of generations, which involves both a haploid and a diploid phase. However, unlike many plants, the **dominant phase in liverwort life cycles is the haploid phase**, also known as the gametophyte.

Let's break down the life cycle to understand this better:


1. Spore Germination: The life cycle begins with a haploid spore. This spore, produced by the diploid sporophyte, germinates into a filamentous structure called a protonema.


2. Gametophyte Development: The protonema develops into the mature gametophyte, the dominant, photosynthetic, haploid phase of the liverwort life cycle.


3. Gametangia Formation: The gametophyte produces specialized reproductive structures called gametangia. These structures contain either antheridia (male) or archegonia (female), which produce haploid sperm and haploid eggs, respectively.


4. Fertilization: In the presence of water, the sperm swims to the egg and fertilizes it, forming a diploid zygote.


5. Sporophyte Development: The zygote develops into the diploid sporophyte, which remains attached to the gametophyte and depends on it for nutrition.


6. Spore Production: The sporophyte produces spores by meiosis, returning the life cycle to the haploid phase. These spores are then released and dispersed, starting the cycle again.

Therefore, while liverworts do have a diploid sporophyte stage, it is relatively **short-lived and dependent on the gametophyte** for survival. The **gametophyte, the haploid phase, is the dominant and longer-lasting phase** in the liverwort's life cycle.

This unique life cycle, with the haploid gametophyte dominating, is a defining characteristic of bryophytes, including liverworts, and distinguishes them from other plant groups where the diploid sporophyte is the dominant phase.
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Diploid sporophyte cells undergo meiosis to produce haploid spores. Each spore goes through mitotic divisions to yield a multicellular, haploid gametophyte. Mitotic divisions within the gametophyte are required to produce the gametes. The diploid sporophyte results from the fusion of two gametes.read more >>