Lecture 5: Vascular Plants

bryophytes (non vascular) plants spend most of their life in sporophyte or gametophyte stage?

gametophyte

vascular plants spend most of their life in sporophyte or gametophyte stage?

sporophyte

what is the name of the clade holding vascular plants

Tracheophytes

what is a branched sporophyte

Branched sporophyte that is independent of the gametophyte (at maturity)

can both vascular and non vascular plants have branched sporophytes

yes

can both vascular and non vascular plants have dichotomous branches

yes

what are the consequences of having a large/tall sporophyte in a heterogeneous environment

1. Air: Light, can make glucose (photosynthesis) and convert it to sucrose, but water is limiting

2. Soil: Water is abundant in the soil, but no light, and tissues require food

what is the earliest ancestor of vascular plants

lycophytes

define microphylls

leaflike structures arranged spirally on the stem. small leaves with a single midvein.

define strobili

club-like clusters of sporgrangium

what are the 3 major clades of lycophytes

1. Lycopodiaceae (16 genera, “Clubmosses”)

2. Selaginella (“Spikemosses”)

3. Isoëtes (“Quillworts”)

draw alternation of generation for lycophytes

(note the self-fertillization is the norm, but they can mate with other lycophytes)

define heterosporous

plants that produce two different types of spores (microspores (male) and megaspores (female)) and two different types gametes (eggs and sperm)

ex. megaspore (spore) —> egg (gamete)

microspore (spore) —> sperm (gamete)

define homosporous

plants that produce one type of spore (plants are usually bisexual) and two different gametes (eggs and sperm)

ex. spore —> egg and sperm (gameteS)

draw homospory alternation of generation

draw heterospory alternation of generation