Question

Week 5: EVOLUTION AND DIVERSITY OF PLANTS - SEEDLESS PLANTS Given 2 hours of discussion and assigned reading on the subject, upon an examination and within 70% accuracy, the student should be able to: Green Algal Ancestor of Plants a. Give four features of charophytes consistent with their sharing a common ancestor sometime in the past with plants. b. Draw an evolutionary tree for plants showing significant innovations during their evolution C Explain the mechanism of "Alternation of Generations" and distinguish between the sporophyte and the gametophyte in the plant life cycle. d. Associate the increased dominance of the sporophyte with plant adaptations to the land environment. Evolution of Bryophytes: Colonization of Land e. Name and describe one example of bryophytes. f. Explain in what ways are bryophytes adapted and not fully adapted to living on land 8. Explain a diagram of the moss life cycle, pointing out significant events. Evolution of Seedless Vascular Plants: Growing Tall h. Name and describe the vascular tissue of plants Name and describe one example seedless vascular plants 1. Explain the observation that these plants but not bryophytes have roots, stems, and leaves. k. Explain in what way(s) are seedless vascular plants similar to bryophytes 1. Explain a diagram of the fern life cycle, pointing out significant events. m. Define the words cuticle, sporophyte, gametophyte, antheridia, archegonia, rhizoid, sporangium, xylem, phloem, heterosporous, homosporous, tracheophyte, bryophytes, pterophytes Remarks: The main purpose is to have the students getting a sense of where plants come from, what makes them plants, how they are classified and the key features of the four groups of plants. They should also be going slowly and carefully through the alternation of generations and be reminded that all plants have all these stages.

Answer 1

c. The term alteration of generations is used to describe a process in the life cycle of eukaryotes. It describes an alteration in forms which occurs in plants.It is the type of life cycle that occurs in plants and algae in Archaeplastida and heterokontophyta that have distinct haploid sexual and dipold asexual stages.

e. Bryophytes are thalloid plants characterised by heteromorphic alteration of generation wherein the sporophyte is either wholly or partially dependent on the gametophyte. Some of the examples are:1.Anthoceros 2.Funaria 3. Marchantia 4. Polytrichym 5. Plagiochasma.

i. Seedless vascular plants examples are: 1. Ferns(Phylum pterophyta).2. Horsetails( Phylum Sphenophyta) 3.Club mosses. 4. Whisk ferns.

h. Vascular tissue is a complex conducting tissue,formed of more than one cell type,found in vascular plants. The primary components of vascular tissue are Xylem and phloem.