Lecture 5: Plant Systematics 1: Algae, Mosses and Ferns

Question 1

Phaeophyta (brown algae)

Answer 1

-Contains chlorophyll a+c
-Exclusively marine
-No root system
-Species of kelp
-Different uses: food, paper, pharmaceuticals, brewing, biofuels

Question 2

Rhodophyta (red algae)

Answer 2

-Accessory pigment: phycoerythrin (absorbs the green part of the spectrum)
-Largest seaweed
-Reproduce sexually: depends on the water currents for fertilization

Question 3

Green algae

Answer 3

-Ancestors of embryophytes (true plants) e.g. angio and gymnosperms
-Share similarities with land plants
-Reproduce sexually
-Have gamete producing chambers (predecessor of archegonia and antheridia, which also adapt to land and are further developed)

Adaptations to move to land:
-Challenge is that water scarcity and lack of structural support
-Development of sporopollenin (waterproof) to prevent zygotes from drying out.
-Movement to land allowed for unfiltered sunlight, access to CO2 and nutrient-rich soil

Question 4

Mosses (general)

Answer 4

-Nonvascular plants
-Metabolism & ecology: due to lack of vascular tissues they remain small in size, cannot retain water, so mosses can become dormant (never grow to large sizes)

-In the division of bryophytes:
–Adapted to land but require moisture for reproduction
–Have a waterproof cuticle
–Drought-resistant sportes

Question 5

Moss morphology: gametophyte on the bottom

Answer 5

-Have stemlike and leaflike structures: gametophytes are the ‘leafy stems’ which form from the PROTONEMA (what the seed germinates into)

-‘Leaf’ structure: essentially like parenchyma (no mesophyll, stomata, veins, petiole)
-‘Stem’ +Rhizoid structure: No vascular tissues, rhizoids anchor plant, most water absorbed through plant surfaces
-Reproduction: have division of gametes into antheridia/archegonia (can be on the same individual/or on different male/female plants)

Question 6

Moss morphology: sporophyte on top

Answer 6

-Have 3 basic components: foot, capsule, seta
-Completely independent from the gametophyte
-Capsule: produces spores

Question 7

Ferns (general)

Answer 7

-Pteridophytes
-Earliest vascular plants
-Lack seeds
-Allowed for tall growth

Different types:
-Evolution of microphylls (small leaves)
-Evolution of megaphylls (big leaves and development of seed plants, giving rise to angiosperms+gymnosperms)