Exam review Flashcards
(114 cards)
What are the characteristics common to all land plants?
- multicellular, eukaryotic
- photosynthetic (using chlorophyll a and b, synthesize simple sugars to create more complex compounds including starch as the main storage molecule)
- have cellulosic cell walls
Which phylum contains the closest relative to land plants?
Charophyta
What surrounds a plant cell?
- Primary cell wall (sits outside of plasma membrane)
2. May also haave a secondary cell wall (found between primary wall and plasma membrane
Most abundant carbohydrate polymer on earth
Cellulose
What makes up a cell wall?
Cellulose, hemicellulose, pectin
What is the role plasmodesmata
- cytoplasmic chanel between cell walls that allows for comunication between adjacent cells
- all for rapid and regulated exchange of molecules betwen cells
Describe the structure of a chloroplast
- surrounded by two membranes
- have their own circular DNA
- contain thylakoid membranes organized into grana
- within thylakoid membranes are photosystems containing chlorophyll a and b
- fluid within the membranes is the stroma where the Calvin-Benson cycle takes place
Name the specialized chloroplasts
- chromoplasts (yellow, orange or red, contain carotenoids)
- leucoplasts (synthesize starch and oils)
(can all interconvert)
Summarize endosymbiotic theory
primitive eukaryotic cell engulfed a photosynthetic bacterium (prokaryote)
Evidence for endosymbiotic theory
chloroplasts and mitochondria
- have their own circular DNA
- are surrounded by two membranes
Describe the role of vacuoles
- stores cell metabolites and waste products
- maintains cell pressure and pH
- may contain anthocyanins
Name the main evolutionary milestones in the evolution of land plants
- developent of the cuticle (protection from UV rays, limits water loss)
- Epidermal pores allowed for gas exchange
- Development of Vasculature (lignification)
- Dominant sporophyte (first observed in seed plants)
- Flowers
State the main characteristics defining bryophytes
- non-vascular
- rely upon water for survival and reproduction (flagellated sperm)
- no true roots (instead use rhizoids)
- no leaves or stems
- dominant gametophyte
Name the bryophyta phyla
Hepaticophyta: the liverworts
Anthocerophyta: the hornworts
Bryophyta: the mosses
State the main charcteristics of the Seedless Vascular Plants (SVPs)
- first lignified plants (lignin reinforces cell walls, allows for upwards growth)
- developed megaphylls (leaves)
- developed sporophylls
- heterosporous
- endosportic development
Name the phyla of the SVPs
Psilorophyta: whisk ferns
Lycophyta: club mosses and quillworts
Equisetophyta: horsetails
Polypodiophyta: ferns
Whisk Ferns characteristics
- no true leaves or roots
- simple branching patter
- associated with mycorrhizal fungi which gametophyte cannot grow without
- homosporous
Lycophyta: Club mosses and quillworts characteristics
- heterosporous
- endosporic development
Equisetophyta: Horsetails
- contain silica deposits in their epidermal cell walls
Polypodiophyta: Ferns
- leaves with sporangia (sporophylls) and large leaves (megaphylls)
Name the phyla of gymnosperms
Pinophyta: Conifers
Ginkophyta: Ginkgos
Cycadophyta: Cycads
Gnetophyta: Gnetophytes
Characteristics of Pinophyta
- create seed cones
- have needle-like leaves (very well suited for cold, dry environments)
- use wind as the primary mechanism for seed dispersal
- some produce resin with antiseptic properties that deter insect attack
Characteristics of Ginkophyta
- only one living species remains
- male and female reproductive structures occur on separate trees
- male gametophyte produces flagellated sperm
Characteristics of cycadophyta
- cone bearing (only have one cone)
- male and female cones occur on separate plants
- male gametophyte produces flagellated sperm