primary/secondary growth and angiosperms Flashcards
what is primary growth?
increase in length, both upwards from the shoot and downwards from the root, resulting from the elongation of cells in the apical meristems
what are the 3 overlapping areas of primary growth?
cell division, elongation, differentiation
describe primary growth in shoots
lateral expansion of stems and roots, causing them to increase in thickness or girth
what do mesophylls and guard cells do?
leaf ground tissue, photosynthesis
-regulate open/closing of stomata
what species undergo secondary growth?
-all gymnosperms
-many eudicots, rare in monocots
-occurs in stems and woody plants in vascular and cork cambiums
where are the secondary phloems and xylems?
xylem and phloem surround vascular cambium
what is the importance of secondary phloems and xylems?
phloem: transports sugar, storage, growth and maintenance
xylem: water/nutrient transport, structural support, storage, tree rings
what does the cork cambium do?
known as periderm, produces cork cells that form outer protective layer
what is a unique characteristic about the periderm?
it is impermeable to water and gases
what do lenticels do?
allow for gas exchange b/w living cells in stem or root
where are the female reproductive structures and what do they consist of?
structures are in the carpel consisting of stigma, style, and ovary
what does the ovule contain?
the ovule contains diploid megasporangium that give rise to an egg
what surrounds the egg?
synergids: pollination/fertilization
antipodal cells: fertilization/seed development
what are the male reproductive structures?
stamens which consist of filament and anther
what happens after the pollen tube is produced?
2 sperm nuclei go to ovary into micropyle and fertilize the egg
what happens to the sperm that doesn’t fertilize the egg?
it combines with the 2 polar nuclei to form a diploid zygote and a triploid endosperm
