Lecture 7 Flashcards
adventitious shoots/roots
roots/shoots which grow along the stem/ any non-root tissue
monocot vs dicot roots
monocots have fibrous roots, dicots have a single tap root with laterals
what is meristem
regions with undifferentiated cells that can continue dividing (stem cells)
totipotency
cells that can continue divide and differentiate ex. spores and zygotes
what are cells in the meristem like
they are small and densely cytoplasmic
what are root buds
roots that produce shoots
what is suckering
lateral roots formed from stems and give rise to other erect stems underground; from above it looks like a ton of trees
what are ramets
multiple genetically identical stems (clones); part of suckering
what are prop roots
roots which arise from the lower side of branches and hold u the plant as it spreads and gets heavy
- ex. ficus trees
what are aerial roots
prop roots, before they make contact with the earth (when theyre still hanging down)
what is clonal propagation
tree that spreads to create a large colony comprising of thousands of trees around itself (arises due to prop root formation and thickening)
what are stilt roots
grow from basal nodes of some monocots and mangrove trees
- emerge from lower nodes than prop roots and contact the ground at an angle
what are buttress roots
aerial extensions of lateral roots; buttress the trunk by spreading all around it in a shallow soil
why are carrots, beets, etc a thing
it is a major survival strategy - food reserves underground (mostly starch)
what is an example of a tap root
carrot, turnip, beet
what is an example of a tuberous root
sweet potato
what are cluster roots
when a ton of extensions form from the main root (looks like a pipe cleaner)
what are runners (stolon)
stems that spread on top of the soil and produce adventitious roots on the nodes
what are rhizomes
horizontally extending stems that run below the soil and have clear nodes, internodes, shoot buds, and adventitious roots
- ex ginger
what are tubers
thickened rhizomes or stolons, where new shoots sprout from the nodes and adventitious roots grow on the lower side
what is a bulb
compressed, concave, fleshy leaves surrounded by outer scaly leaves and enclosing shoot buds borne on a compressed stem
- onion, tulip
what is a corm
solid, have fibrous as well as contract roots
- taro, eddoes
what are bulbils
tiny bulbs borne on a scape that look like a flower but do not get pollinated
- ex garlic
what is a scape
a long leafless stalk growing out from an underground bulb, corm, rhizome
what is vivipary
when an embryo starts germinating prematurely on a parent plant
(bulbil makes leaf and roots while still attached)
what is somatic embrogenesis
formation of an embryo without pollination and fertilization (no gametes involved)
- considered an embryo bc it has two meristems (SAM and RAM)
can somatic embryogenesis occur under natural conditions
yes! when the environment doesn’t allow for flowering or if the plant gets cut in some way you might see tiny structures hanging onto the stem without going through the process of forming a flower or embryo
what are epiphytes
plants growing on other plants
what are xerophytes
cacti and succulents; have true leaves that shrivel up under harsh conditions to make spikes
