enriched bio Flashcards
outcome of bonsai experiment
fertilization did not increase the growth rate of the small trees
they didnt exhibit a dwarf phenotype due to nutrient deprivation
might be the small root structure
explain the two worlds land plants live in
above ground = shoot systems acquire sunlight and co2
below ground = root systems acquire water and minerals
what did algal ancestors of plants absorb
water, minerals and co2 from the water they lived in
what did earliest land plants have
nonvascular plants that grew photosynthetic shoots above the shallow water
leafless shoots had waxy cuticles and few stomata = allowed them to avoid excess water loss and permits some exchange of co2 and o2
early land plants anchoring and absorbing functions were assumed by
base of the stem or by threadlike rhizoids
land plants evolved and increased in number lead to
competition for light water and nutrients
evolution of vascular tissues like xylem and phloem lead to
made possible the development of extensive roots and shoots systems that carry out long distance transport
what does xylem do
transports water and minerals from roots to shoots
what does phloem do
transports products of photosynthesis from where they are made or stores to where they need to be
describe the plants that had an advantage in absorbing light
taller plants with broad flat appendages
describe the plants that need more water
increased surface area (broad, flat appendages) lead to more evaporation
describe the plants that require more anchorage
larger shoots
what did greater shoot heights do
further separated the top of photosynthetic shoots from the nonphotosynthetic parts below ground
what did natural selection favour
plants capable of efficient long distance transport of water minerals and products of photosynthesis
what do the adaptations have to do
compromise between enhancing photosynthesis and minimizing water loss
diversity in plants is due to
differences in branching patterns, dimensions, shapes, and orientations of the shoot’s two components
name the shoots two components
stems and leaves
what does shoot architecture facilitate
light capture for photosynthesis
what do stems do
supporting structures for leaves
conduits for the transport of water and nutrients
name the two architectural features affecting light capture
branching pattern and length of stems
describe tall plants
thick stems, greater vascular flow, stronger mechanical support
describe vines
rely on other objects to support their stem
describe woody plants
stems become thicker through secondary growth
branching enables
plants to harvest sunlight
for photosynthesis more effectively