Lecture 1

Question 1

Define “plant”

Answer 1

-Phylogenetic perspective:
Organisms within the clade Embryophyta
-Ecological perspective:
Primary producers that use
light energy to manufacture
food, and evolve O2 as
byproduct

Question 2

Explain why there is sometimes ambiguity in deciding whether an organism is a plant

Answer 2

-“Ecological plants” includes all photosynthetic primary producers. It is a polyphyletic group: several distantly related eukaryotes “stole” photosynthesis.
-“Phylogenetic plants” (i.e., Embryophyta) is a lineage sharing common ancestry with green algae, and adapted for life on land. It is a monophyletic group.

Question 3

Correctly use the terms monophyletic, polyphyletic, and paraphyletic

Answer 3

Monophyletic : An ancestor + all of its descendants
Polyphyletic: 2 or more ancestors, true common ancestor excluded
Paraphyletic: Ancestor + SOME of its descendants