Lecture 14: Land Plants Flashcards
what is a major way that plants differ from protists?
-plants are multicellular
challenges to land living?
- drying out (need to survive long term in air)
- structural support by itself (w/o the support of a water column)
- reproduction (dependent on water to transport gametes so they gotta find a new way to reproduce)
adaptation to land
- embryophyte
- cuticle
- stomata
- pigmentation
- fungal relationship
- tracheid cells
- seeds
embryophytic adaptation
-have structure to protect developing embryo and prevent it from drying out
cuticle adaptation
-waxy substance that traps water inside of plant thus hard to get air in which has CO2 which is necessary
stomata adaptation
-holes that open to let air in, then close to keep water in
pigmentation adaptation
-blocks out UV rays since water no longer will
fungal relationship adaptation
-having a relationship with soil fungi helps them get nutrients
tracheid cells
-specialized cells that allow for water and nutrient transport from the roots to the leaves
tracheid cells adaptation
-allows the plant to become much larger organisms
seeds
-ultimate form of embryo protection
diplontic life cycle
- have only diploid stages of life(multicellular)
- gametes never undergo mitosis
haplodiplontic life cycle
- have multicellular, haploid, and diploid cycles
- almost all plants have two forms (haploid gametophyte and diploid sporophyte)
- have multicellular haploid and diploid stages
sporangia
- specialized structures in the sporophyte
- where diploid spore mother undergoes meiosis and produce haploid spores
spore mother cells
-in sporangia, undergo meiosis and produce the haploid cells
spores
-any haploid cell that will divide by mitosis and become multicellular
archegonium
- produces eggs
- where mitosis of gametophytes occur
antheridium
- produce sperm
- where mitosis of gametophytes occurs
syngamy
-the fusion of gametes (fertilization)
gametophyte
- haploid generation that gives rise to gametes
- alternates with sporophytes
how do the events of meiosis and syngamy shape the haplodiplontic life cycle?
- meiosis goes from diploid to haploid
- syngamy goes from haploid to diploid
dominant life stages traits
- varies within in plants
- haploid stages sensitive to recessive mutations