Question

1. In a transverse section, how could you discern whether you are examining a root or stem or a eudicot. (2 pts.)

2. Fill in the blank with an appropriate family (not the genus) that we have studied to date: Rhyniaceae, Lycopodiaceae, Selaginellaceae, and Isoetaceae (2 pts.).



1.___________ Sporangia are heterosporous; leaves are simple, possess one vein and are ligulate; leaves often are dimorphic, two lateral (ventral) rows of long leaves and two upper (dorsal) rows of smaller leaves.



2._________ Stems are corm-like, leaves resemble quills, possess a single midrib, and form a basal rosette; megasporangia occur on the outer leaves and microsporangia occur on the inner leaves.



3. _______ An extinct family that includes some of the first land plants; lacked both roots and leaf-bearing shoot system; stems possessed a protostele; sporangia were terminal.



4. ______. Rhizomes branch and possess aerial branches and adventitious roots, leaves small, microphyllous, plants are homosporous, subterranean gametophytes are dependent on a fungus for continued growth.

Answer 1

To differentiate a root from a stem in a eudicot, observe the arrangement of vascular tissue; stems have a ring of vascular tissue, while roots show a central vascular column. Lycopodiaceae family classification includes: Selaginellaceae known for heterosporous sporangia and dimorphic ligulate leaves; Isoetaceae with corm-like stems and quill-like leaves; Rhyniaceae, an extinct group without leaves or roots; and Lycopodiaceae, which have branching rhizomes with small leaves.

Step-by-step explanation:

In a transverse section, distinguishing a root from a stem in a eudicot can be done by observing the arrangement of vascular tissue. Eudicots are characterized by a vascular tissue ring within stems, while in roots, vascular tissue is arranged in a central column surrounded by a cortex. Moreover, roots lack nodes and internodes found in stems and tend to have a prominent main root unlike the diffuse root system often seen in monocots.

Classification of Lycopodiaceae Family Members

1. Selaginellaceae - Sporangia are heterosporous; leaves are simple, possess one vein and are ligulate; leaves often are dimorphic.
2. Isoetaceae - Stems are corm-like, leaves resemble quills, possess a single midrib; megasporangia and microsporangia occur on different leaves.
3. Rhyniaceae - An extinct family that includes some of the first land plants; stems possess a protostele; sporangia were terminal.
4. Lycopodiaceae - Rhizomes branch and possess aerial branches and adventitious roots, leaves small and microphyllous; plants are homosporous.