ib bio 9.3 - 9.4 plant struct, grwth, repro Flashcards
define meristem
Meristems are tissues in a plant consisting of undifferentiated cells capable of indeterminate growth
define indeterminate growth
plant growth in which the main stem continues to elongate indefinitely without being limited by a terminal inflorescence or other reproductive structure
define node
A point in a plant stem at which one or more leaves are attached.
define tropism
A tropism is growth or movement towards or away from an external stimulus, such as light, gravity or chemicals
define phototropism
Phototropism is growth towards or away from an external light source
define shoot
Apical meristems occur at shoot and root tips and are responsible for primary growth (i.e. plant lengthening)
define shoot apex
Shoot apex is the apical part of the stem. It contains multipotent stem cells, Mitosis and cell division in the shoot apex provide cells needed for extension of the stem and development of leaves. Plant hormones control growth in the shoot apex. Plant shoots respond to the environment by tropisms.
define pollination
Pollination - The process of pollen transfer from an anther to a stigma
define fertilization
Fertilization - The fusion of a male gamete with a female gamete inside the ovule.
define seed dispersal
Seed dispersal - The movement/transport of seeds away from the plant. Fruits which develop from fertilised ovules, function as a mean of seed dispersal
define germination
Germination is the process by which a seed emerges from a period of dormancy and begins to sprout.
define self pollination
self-pollination, the pollination of a stigma by pollen from the same flower or another flower on the same plant
define cross pollination
Cross-pollination involves transferring pollen grains from one plant to the ovule of a different plant.
define photoperiodism
photoperiodism, the functional or behavioral response of an organism to changes of duration in daily, seasonal, or yearly cycles of light and darkness
angiosperm, gymnosperm (conifer), filicophytes, bryophytes
angiosperm: any plant that produces a flower or fruit. (flowers/trees)
gymnosperm: any vascular plant that reproduces by means of an exposed seed, or ovule (conifers)
filicophyte: any of numerous flowerless, seedless vascular plants that produce spores giving rise to free-living gametophytes and that often have dissected leaves (fern)
bryophyte: a small flowerless green plant of the division Bryophyta, which comprises the mosses and liverworts
monocots vs dicots
monocot - single cotyledon, narrow/long leaf, parallel veins, vascular bundles (scattered), flower petals grow in multiples of 3
dicot - two cotyledons, broad leaf, network of veins, ring of vascular bundles, flower grows in multiples of five
gymnosperms and dicots are…
the only types of plants that have both apical and lateral meristems
gymnosperms and dicots are…
the only types of plants that have both apical and lateral meristems
compare apical and lateral meristems
both - two types of meristematic tissue that are responsible for the growth of a plant
apical - primary growth (length), occurs at tip of shoots and roots, produces new leaves and flowers
lateral - secondary growth (wide), occurs at cambian (btwn xylem/phloem), produces bark on trees
role of auxin in apical growth in plant stems and in apical dominance
auxin stimulates the growth of the apical bud and inhibits the growth of side shoots from lateral buds. auxin influences stem elongation, regulates formation, activity, and fate of meristems
role of auxin in phototropism in plants
in a stem, the shaded side contains more auxin and grows longer which causes the stem to grow towards the light. auxin increases flexibility of plant cell walls which is main factor of limiting plant cell growth
auxin changes…
patterns of gene expression in order to promote phototropism and apical growth in plants
process of micropropagation, applications, and pros/cons
microprop is cloning identical cells/small pieces of plant tissue, used to regenerate new plants
applic - used for germplasm storage and protection of endangered species
pros/cons - facilitates growth, storage, and maintenance of plants within small spaces which makes it costly
darwins experiments w coleoptiles of plants and the conclusion they made from experiments
if light was shone on a coleoptile from one side, the shoot bends/grows toward the light
relationship between animals and flowers they pollinate
mutualistic relationship, pollinators receive nutrients and flowers are allowed growth and reproduction
list and describe adaptations of flowers to attract animal pollinators
bright colored petals/sepals and intense odor/slight odor
list and describe vectors for seed dispersal and outline why seed dispersal is important 4 survival of plant species
it helps plants to grow within new areas and animals can take fruit and spread it to new places. if plants grow too closely to one another, competition regarding nutrients, light, and water will occur
list and describe environmental conditions necessary for seed germination
all seeds need water, oxygen, and proper temp in order to germinate. certain seeds need proper lighting as well. some germinate well in full light and others germinate in darkness
explain the process (steps) of seed germination after favorable environmental conditions are encountered
temperature, moisture, air, and light conditions must be correct for seeds to germinate. water activates enzymes which begin seed growth, seeds grow a root to access water, shoots begin to appear, seed sends shoot towards surface to grow leaves to harvest
role of phytochrome in flowering both short day and long day plants
(Pfr promotes flowering in long day and inhibits flowering in short day)
describe and identify conditions necessary to induce flowering in long day and short day plants out of season
Short day plants can be forced to flower by artificially increasing dark time by using blinds or blocking out light during the day. With long day, turning on the grow lamps earlier, stop interrupting the night cycle
