-
Ancestral green algae (Chlorophyda) that did not evolve into land plants are called __
Charophyceans (artificial grouping that no longer exists)
green algae that lived on the edge of the water (stream, river, creek which have a selective agent of a current) so it was dry at some point. Did not depend on water all the time
-
Charophyceans are broken down into __
Charales & Coleochaetales (considered the closest relatives to land plants)
-
Land plants started off as __, which are seedless nonvascular.
bryophytes
(stays short because they don’t have good transportation. has tiny sporophytes)
-
Bryophyte clades
- Liverworts, Hornworts, and Mosses
-
Vascular plants started off as __
seedless
-
seedless vascular plants
- Lycophytes & Pterophytes (ferns)
-
vascular seed plants
- Gymnosperms and Angiosperms
-
new adaptations of Charophyceans (compared to green algae)
- rosette cellulose-synthesizing complex: allowed them to stand upright & survive a short period of time without desiccation (Green algae had parallel.)
- sporopollenis: a polymer that blocked water from leaving their bodies
-
Charophyceans are part of the group, __, but are not part of the kingdom, __, which are made up of land plants.
Streptophyta; Plantae
-
From transition from water to land, plants have increased __
support and movement of water and nutrients
(Plants started off with little structural support, which were found in fossils and present day mosses)
-
Splitting from Charophyceans, plants developed these features:
- apical meristem
- alternation of generations
- walled spores produced in sporangia
- multicellular gametangia
- multicellular, dependent embryos
-
apical meristem
contains totipotent cells that have the ability to differentiate into different cells
-
alternation of generations cycle of land plants
Sporophyte (diploid multicellular individual) uses sporangia (reproductive organs) to do meiosis and produces spores (haploid): 2n > n
Spores will grow (mitose) into a gametophyte (haploid multicellular individual), which uses gametangia (reproductive organs) to do mitosis (n>n) and produces gametes. Fertilization occurs and a zygote is formed (2n).
The zygote will grow (mitose) into a sporophyte. The gametophyte will eventually become “absorbed” by the sporophytes, which takes in its nutrients. Cycle continues
-
alternation of generations image
-
Walled spores are produced in sporangia to __
protect from desiccation (due to lack of water in the environment) when the spores are spewed out from the sporangia.
Moss and ferns do not need walled spores because they are by the water.
-
Gametangia that produce sperm is called __
Antheridia
-
Gametangia that produce eggs are called __
Archegonia
-
The eggs are protected and retained in the __ structure by the gametophyte (parent generation) and the sperm comes and fertilizes it.
archegonial
-
multicellular dependent embryos
Sperm goes to the retained egg in the archaegonial structure and fertilization and growth will occur in the archaegonial structure. (Sporophyte grows out of the gametophyte.)
-
cuticle
waxy covering that is hydrophobic and holds in water, protects the plant from desiccation
-
secondary compounds
used initially to fight infections against bacteria, viruses, and fungus, and later to protect the plants from herbivores
-
Bryophytes are __ dominant
gametophyte (haploid)
-
__ allow bryophytes to anchor to the ground
Rhizoids
(Roots in vascular plants are slightly analogous structures.)
-
special characteristic of a moss life cycle
- They are heterosporous: Microsporangia make microspores which grows into gametophytes with only antheridia. Megasporangia make megaspores which grows into gametophytes with only archegonia.
- A sperm swims through moisture and goes to an archegonium and fertilizes the egg.
-
Mature sporophyte structures in bryophytes, which are seen growing out of the female gametophytes, are called __
seta, capsule (sporangium), and foot
-
The development of a vascular system allows a plant to __
grow upward (since they have transportation)
-
special characteristic of a fern life cycle
- Most ferns are homosporous: produce a single bisexual gametophyte, which are developed from a fern spore. Cross-fertilization occurs between gametophytes.
- Fern have clusters of sporangia called sori.
- Fern sperm uses flagella to swim to the eggs in the archegonia.
Homospores are primitive to heterospores.
-
homosporous vs heterosporous
|
|