Plant Structure and Growth Chapter 35. The Angiosperm Body. Two Classes based on Embryo s: 1. Monocots : single Cotyledon (seed leaf) 2. Dicots : two cotyledons. Three Basic Organs Roots Stems/Shoots Leaves. Monocots vs. Dicots. Root System.
Two Classes based on Embryo s:
1. Monocots: single Cotyledon (seed leaf)
2. Dicots: two cotyledons
Dicots have main Taproot: one large vertical root, small lateral roots, firm anchor. Energy storage Root crops harvested before flowering
Monocots: fibrous roots, thread like, short,
Root Hairs: tiny fibers increase surface area, have Mycorrhizae.
Adventitious roots: roots that rise up above ground, or other unusual area
Phloem: food conducting; sieve tube members, no nucleus
Chains of Sieve-tube members: alive at maturity,
Angiosperms have sieve plates b/w cells w/ pores.
Each sieve tube member has companion cells,connected to sieve tube by plasmodesmata, helps ST and loads sugar into phloem.
Plane: directional growth
Asymmetrical Growth:one daughter cell receives more of cytoplasm
Guard Cells need both asym., and plane division
Preprophase Band: microtubules in cortex set plane of division