BIOL 172 Lecture Notes - Lecture 5: Non-Vascular Plant, Meristem, Microphyll
nonvascular plants vs vascular plants
● Nonvascular: plants w/o water and food transport tissues
○ Ex. mosses
● Vascular: plants with transport and food transport tissues
○ Ex. ferns
3 periods of plants
1. Origin of land plants (475 mya)
● Bryophytes arose here
● Most lack vascular tissue
2. Origin of vascular plants (425 mya)
● Evolved from moss-like plant
3. Origin of extant seed plants (305 mya)
mosses vs ferns life cycle
● Vascular tissue..
○ Absent in moss
○ Present in ferns
● Both have flagellated sperm, a poor adaptation to the terrestrial environment b/c it could
require swimming to the ocean for sexual reproduction
apical meristem: localized areas of cell division. Increases length of root and shoot tips
● Allows shoot to seek CO2 and light
○ Allows plant to grow out and up
● Allows root to seek water and minerals
○ allows plant to grow deep into the soil
Male and female gametangia
Male: moss antheridium with sterile cells
● Sperm is produced
Female: moss archegonium with sterile cells surrounding egg
Microphylls vs megaphylls: leaves found in seedless, vascular plants
● Microphylls: 410 mya
○ single strand of vascular tissue
○ Originated as sporangia w/o vascular tissue. Vascular tissue eventually grew into
microphylls
● Megaphylls: 370 mya
○ Branched vascular tissue
○ Plants already had visible leaves, which came to be KNOWN as megaphylls
Ferns: are homosporous
● One type of spore gives rise to bisexual gametophyte
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Document Summary
Nonvascular: plants w/o water and food transport tissues. Vascular: plants with transport and food transport tissues. 3 periods of plants: origin of land plants (475 mya) Most lack vascular tissue: origin of vascular plants (425 mya) Evolved from moss-like plant: origin of extant seed plants (305 mya) mosses vs ferns life cycle. Both have flagellated sperm, a poor adaptation to the terrestrial environment b/c it could require swimming to the ocean for sexual reproduction apical meristem: localized areas of cell division. Allows shoot to seek co2 and light. Allows plant to grow out and up. Allows root to seek water and minerals. Allows plant to grow deep into the soil. Female: moss archegonium with sterile cells surrounding egg. Microphylls vs megaphylls: leaves found in seedless, vascular plants. Plants already had visible leaves, which came to be known as megaphylls. One type of spore gives rise to bisexual gametophyte.
