Seedless Vascular Plants (unit 4)

Seedless vascular plants include ferns, whisk ferns, horsetails, lycopods, and other similar plant groups. Gnetophytes, cycads, and conifers are not part of the seedless vascular plants group.

Seedless Vascular plants were dominant around 400 million years ago, during the Devonian period. Coal has derived from the bodies of these ancient plants due to their abundance during this time.

Seedless vascular plants have evolved various adaptations to thrive on land, including having a thick, waxy cuticle to prevent desiccation, possessing true vascular tissues for efficient transport of water, sugars, and nutrients, and providing structural support through xylem. These adaptations are crucial for their survival outside of water.

Lignin is a complex organic polymer that is responsible for providing rigidity to cell walls in plants, making them rigid and woody. All vascular plants contain lignin in their cell walls to provide structural support.

Homosporous plants produce a single type of spore that gives rise to potentially bisexual or hermaphroditic gametophytes. This characteristic is common in many ferns.

Heterospory in seedless vascular plants refers to the production of two different sizes of spores – microspores and megaspores, which give rise to male and female gametophytes respectively. This allows for the development of unisexual gametophytes in these plants.

Phylum Pteridophyta includes ferns, which are an example of this group. Most ferns are homosporous, meaning they produce a single type of spore, but some fern species can be heterosporous, producing two types of spores.

Ferns (Pteridophyta) are generally diverse with approximately 12,000 species. They are usually found in damp, shady ravines, although some species can also be found in prairies. The incorrect answers provided do not accurately represent the number of species or their habitats.

The life cycle of a fern is characterized by a sporophyte dominated stage with an independent, free-living gametophyte stage. This is the opposite of the mistaken options provided.

In Homosporous Ferns, spores are produced through meiosis, which is a type of cell division that results in four daughter cells with half the number of chromosomes as the parent cell.

Sori are typically found on the underside of leaves and actively disperse spores. They are not just random clusters but have a specific term for their arrangement.

Sperm Gametophyte is typically shaped like a heart due to its functional structure and role in reproductive processes.

Young sporophytes of Hepaticophyta-ferns are known to grow relatively large and have a longer lifespan compared to other plant species. This is due to their unique growth patterns and reproductive strategies.

Antheridiogen is a molecule that promotes male gametophyte development, leading to genetic variability in homosporous ferns and promoting out-crossing for increased genetic diversity.

Lycopods are a group of plants that include more than 1,000 species globally. The other options provided do not accurately represent the diversity of lycopods.

The sporophytes of lycopods are capable of photosynthesis and do not rely on external food sources for nutrition.

Lycopod Gametophytes can either be green and photosynthetic or subterranean and non-photosynthetic. The incorrect answers provided do not accurately represent the characteristics of Lycopod Gametophytes.

In lycopods, the gametophytes are independent entities that do not rely on the sporophyte for nutrition, unlike some other plant types where the gametophytes may depend partially or completely on the sporophyte.

Seed plants exhibit a mix of sexual reproduction, with some members being heterosporous, producing two types of spores - microspores and megaspores.

Microspores develop into male gametophytes, while megaspores develop into female gametophytes in plants.