Topic 13 Flashcards
What protist supergroup are land plants a part of?
Archaeplastida
What are some characteristics of plants?
i) Multicellular
ii) photosynthetic eukaryotes
iii) cell walls made of cellulose
iv) have chloroplasts with chlorophyll a and b
v) store photosynthetic sugars
vi) alteration of generations
What did land plants evolve from?
Freshwater green algae (charophytes)
What are the three traits shared between land plants and charophytes?
i) Rings of cellulose-synthesizing proteins
ii) Homologous structure of flagellated sperm
iii) Phragmoplast formation during cell division
How did movement to land occur for plants?
Decreased competition Increased photosynthesis O2 atmosphere Soil rich in nutrients Few predators
What are two challenges to living on land for plants?
i) Scarcity of water
ii) Lack of structural support
What adaptations of land plants enabled colonization of land?
i) Sporopollenin
ii) Adaptations for water conservation
iii) Vascular tissue for internal transport
iv) Compartmentalization
What is sporopollinin?
A durable polymer secreted by charophyte zygotes in the cell wall
What are two adaptations for water conservation?
i) Waxy cuticle
ii) Stomata
What do you call pores in the epidermis of leaves and other photosynthetic organs?
Stomata
What is the xylem?
Cells that carry water and minerals up from roots that’s strengthened by lignin
What plant cells distribute organic products?
Phloem cells
What are the five shared derived traits of Plantae that separate plants from charophytes?
i) Alternation of generations
ii) Walled spores produced in sporangia
iii) Multicellular gametangia
iv) Multicellular, dependent embryos
v) Apical meristems
What is alternation of generations?
The life cycle of land plants alternates between the sporophyte and the gametophyte
What is a sporophyte?
Diploid multicelluar generation specialized for dispersal
How is the sporophyte created?
Through the fusion of gametes (fertilization) to give rise to diploid sporophyte which produces haploid spores by meiosis
What is the gametophyte?
Haploid multicellular generation specialized for fertilization
What does the gametophyte do?
Produves haploid gametes by mitosis
What are the five steps of alternation of generations?
i) Gametophyte produces haploid gametes by mitosis
ii) Two gametes unite and form diploid zygote
iii) Zygote develops into diploid sporophyte
iv) Sporophyte produces haploid spores by meiosis
v) Spores develop into haploid gametophytes
Where does the sporophyte produce spores?
Sporangia
What do you call diploid cells that undergo meiosis to generate haploid spores?
Sporocytes
Where do gametophytes produce gametes?
Gametangia
What are female gametangia that produce eggs and are the site of fertilization?
Archegonia
What are male gametangia that produce and release sperm?
Antheridia
Where are the diploid embryos in plants?
Within the archegonia of the female gametophyte
What are localized regions of cell division at the tips of shoots and roots?
Apical meristems
What are nonvascular plants called?
Bryophytes
What are the two clades that make the paraphyletic group of seedless vascular plants?
Lycophytes (mosses) and monilophytes (ferns)
What is a seed?
The embryo and nutrients surrounded by a protective coat
What two clades make the seed plants?
Gymnosperms and angiosperms
