Week 9 Plant Evolution: Alternation of Generations, Bryophytes, and Ferns

What is the alternation of generations in plants?

The alternation of generations refers to the life cycle of plants where they alternate between a haploid gametophyte stage and a diploid sporophyte stage.

What is the dominant generation in bryophytes?

The gametophyte generation is dominant in bryophytes.

What is the dominant generation in pteridophytes?

The sporophyte generation is dominant in pteridophytes.

What are the main challenges plants faced when moving to land?

Challenges include gravity (lack of buoyancy), finding water, obtaining nutrients, and the need for new reproductive strategies.

What adaptations did plants develop to overcome challenges on land?

Adaptations include lignin and secondary growth, a vascular system, stronger roots, and the development of spores and seeds.

What type of sperm do bryophytes, lycophytes, and pteridophytes have?

All three groups have flagellated sperm.

What is the life cycle of mosses characterized by?

Mosses have a life cycle that includes male gametes in antheridia, female gametes in archegonia, and a sporophyte that develops from fertilization.

What is the role of sporangia in the life cycle of ferns?

Sporangia produce spores that are protected by an indusium in ferns.

What is the significance of the vascular system in land plants?

The vascular system allows for efficient transport of water and nutrients, supporting larger plant structures.

What are the three main groups of seedless plants?

The three main groups are bryophytes, lycophytes, and pteridophytes.

What is the difference between gametophyte and sporophyte in terms of ploidy?

The gametophyte is haploid (1N), while the sporophyte is diploid (2N).

What is the function of the protonema in mosses?

The protonema is the early stage of the gametophyte that develops from spores and is responsible for anchoring and nutrient absorption.

How do ferns reproduce?

Ferns reproduce through spores produced in sporangia and have a life cycle that includes both gametophyte and sporophyte stages.

What is the evolutionary trend regarding plant dominance from gametophyte to sporophyte?

The trend shows a shift from gametophyte dominance in early plants to sporophyte dominance in more advanced land plants.

What is the significance of seeds in plant evolution?

Seeds provide protection and nourishment for the developing plant embryo, allowing for greater survival and dispersal.

What is the term for plants that do not have vascular tissue?

Nonvascular plants, such as bryophytes.

What adaptations allow plants to reproduce in terrestrial environments?

Adaptations include the development of spores, unflagellated sperm, and seeds.

What is the function of lignin in plants?

Lignin provides structural support and rigidity, allowing plants to grow taller and withstand gravity.

What are the two main types of vascular plants?

Lycophytes and pteridophytes.

What is the role of the character matrix in plant classification?

The character matrix is used to compare traits among different plant groups to understand their evolutionary relationships.