Test 1 Flashcards
Animal cell
- Semipermeable
- Phospholipid bilayer
- Proteins (cholesterol can solidify cytoskeleton)
Nucleus
- double membrane
- linear chromosomes
- chromosome number varies (can be polyploid)
Mitochondria
-cellular respiration
ER
Smooth - lipid synthesis - membrane synthesis Rough - protein synthesis
Ribosomes
- protein synthesis
Golgi
-Processing/ sorting/shipping proteins
Cytoskeleton
- actin filaments
- microtubules
- gives structure
Perixisome
- fatty acid metabolism
Tonoplast
- storage (water, pigments, ions, waste)
- helps to keep shape (turgor pressure)
Cell wall
- skeletal system (strength, structure, support)
- cellulose (polymer of glucose, beta 1-4 linkage)
- starch (alpha 1-4 linkage)
Cell wall pt.2
Primary - all plant cells
- pectin matrix (stretchy/flexible, aqueous, water permeable, thin)
Secondary- some plant cells
- lignin matrix (water permeable, rigid, thin to thick
Middle lamella - glues cells together
Symplast = inside cell membrane
Apoplast= outside cell membrane
Plasmodesmata
- Symplastic connection
Plastids
- double membrane bond
- contain circular DNA
- ribosomes
- can replicate by binary fission
- starts as pro plastid
- +/- thylakoid membrane
- chloroplasts (green), chromoplasts (red), leucoplasts (no pigment)
Endosymbiotic theory (plastids)
Evidence: - circular DNA double membrane (outer membrane looks like euk, inner membrane looks like pro) - replicate by binary fission like prok. - ribosomes look like prokaryotic
Tonicity
Animal cells are isotonic
Plant cells aren’t and have turgor pressure
Tissue growth
Animals= zygote -> cell everywhere -> cell growth stops
Plants= zygote -> cell growth at apical meristem -> cell growth continues
- shoot apical meristems (SAM)
- root apical meristems (RAM)
- all plants have them
- primary growth =herbaceous
- increases length of plant
3 primary tissues
- dermal tissue: protection
- primary vascular tissue: transfer
- ground tissue: photosynthesis, storage, etc.
Differentiated cells
Protoderm -> dermal tissue
Procambium -> primary vascular tissue
ground meristem -> ground tissue
Dermal tissue (protection)
- Epidermis
- 1 cell layer
- 3 cell types:
- pavement cells (secrete cutin, cuticle, big vacuoles, no chloroplasts)
- guard cells are in pairs (gas exchange, have chloroplasts)
- trichomes - plant hairs (anti herbivory, physical, chemical, env, decrease water loss, can form root hairs, more SA more H2O)
Ground tissue (majority of plant body)
- Photosynthesis, structure and support, storage - carbs, H2O
- Parenchyma cells: most common cell type
photosynthesis, storage, metabolism
large, round, thin, primary walls
can differentiate into other cell types - collenchyma cells
provide support - flexible soft
elongated, narrow
clustered, thick cell wall (primary)
alive at maturity
-sclerenchyma cells
support and stucture -rigid, inflexible
thick secondary walls
*fibers- elongated
*sclereids - roundish
dead at maturity
Vascular primary tissue
- primary xylem (long distance transport of water and minerals)
- primary phloem (long distance transport of carbs)
- vertical support
Xylem
- xylem parenchyma: storage, alive
- xylem fibers: structure, support, dead
- tracheids: long distance support, dead
- vessel elements: long distance support, dead. Stacked to make a vessel (more efficient way to move H20, short and wide)
Phloem
- phloem parenchyma: storage, alive
- phloem fibers: structure and support, dead
- steve tube member: long distance transport ( to symplastic, but not to nuclei, ribo, mito, vacuoles), elongated and live
Dr. Katherine Esau
- 1898 -1997
- studied plant anatomy
- wrote a book called “anatomy of seed plants”
Organs
Monocots - grasses, grains, always herbaceous
Eudicots - can be herbaceous or woody
Roots -underground portion of the plant
- water and mineral uptake
- anchorage and support
- carbohydrate storage
Morphology:fibrous- many similar sized roots, dense shallow, good anchorage, poor support
tap-main large axis with smaller roots, deep, good support, good uptake from deep sources, lots of carb storage
Root cap
- protect root apical meristem (RAM)
- facilitate growth
- secrete polysaccharide -> lubricant
- sense of gravity
- at the tip of the root
Root epidermal cell types
- pavement cells (no cuticle, no guard cells)
- trichomes (root hairs)
Aquaporins
- water channels - how water gets into/ out the cell
- filtered water can go into the root from the cell and go from cell to cell
- unfiltered water moving apopstatically (never crosses the membrane)
Endodermis
- single cell layer
- have casparian strip in wall (made of Suberin, stops movement of H2O forces to go through membrane)
- water moves into endodermal cells via aquaporins (filtered)
Pericycle
- composed of undifferentiated parenchyma totipotent
- responsible for making lateral roots
Root modifications
Prop root - grow tall and skinny, no tap root system (bamboo), vertical support, adventitious roots
Buttress roots - associated with trees that grow in specific env. Tall trees with shallow roots, compete for nutrients and sunlight
Pneumatophore - allow gas exchange in wet environments
Epiphytic root - anchor to another plan, photosynthetic
Contractile roots - bulbs
Root associations
Mycorrhizae -> fungal associations (symbiotic) - plant gets increased water and mineral utake - fungus gets carbs Endo - most common Ecto - mostly trees\ Rhizobial -> bacterial associations - Fabaceae: beans, peas, penuts - Bacteria gets carbs and home - Plants get organic nitrogen
Stems
- long distance transport, connects roots to aerial organs
- structure and support positioning of other organs
- SAM makes all aerial organs, leaves, flowers and new stems
Primary stem growth
- Increases length of a plant
- SAM/RAM
- three primary meristems: protoderm -> epidermis, ground meristem-> ground tissue, procambium-> primary xylem and phloem
Secondary stem growth (some eudicots)
- increases width
- woody tissue, only roots and stems
- 2 secondary meristems: vascular cambium ->secondary xylem ad phloem (laterally located), cork cambium -> periderm (bark)
Cork cambium
- Outer bark: cork cells outside, dead, protection, replace epidermis, lenticels for gas exchange
- Inner bark - cork parenchyma inside, alive, storage, replace ground tissue
Cork tissue
- Thickness varies
- Protect from temp. extremes (insulates), herbivores, insects, mild fires
- mechanical injury
- water loss
Stem modifications
Tuber- carb storage (potato, yams)
Cladophyll - look and function like leafs
Thorn - for protection
Rhizome - root-like stem, grow horizontally underground
Stolon- above ground, horizontal growth
Tendril - wrap around substrate ( climbing)
Succulent - H20 storage
