Dicot, herbaceous root- no pith

1. parts on diagram- xylem arms, pericycle(meristematic parenchyma, lateral roots)(grows outward), vascular cambium(separates xylem and phloem), cortex, ameyloplasts in cortex cells, endodermis, epidermis, phloem patches with companion cells
   

1. epidermis cortex
   
2. endodermis pericycle
   
3. xylem and phloem are separate
   
4. do have a pith
   
5. no vascular cambium (no need for it)
   
6. palm tree-monocot, modified primary growth
   

1. trees with wood also put wood on roots
   
2. need vascular cambium and cork cambium (since they impede water flow, they fan back from growing tips(functional part)
   
3. analogous process occurs( as in stem) except cork cambium is derived from pericycle(which has meristematic cells)
   

1. prop roots- are adventitious(grow of off stem tissue), start at a bud in lower part of stem, grow downward
   
2. epiphytes- haustoria enter tree(parenchymal cell with xylem), have aerial roots, ex. orchids-have photosynthetic roots that may absorb water from air
   
3. breathing roots- pneumatophore, ex. Black Mangrove Tree in the Everglades (swamps)
   
4. contractile roots- made of cortical cells, can shorten, corm grows upward and contractile roots pull corms back underground
   

1. 10^8 microorganisms per gram of soil
   
2. include fungi, algae, and protozoa
   
3. worms and ants-aerate; worms leave fecal castings
   

1. 30-60% of soil open
   
2. What gases are there in soil? soil air less O2, more CO2 (roots use up O2 and expel CO2)
   

1. water tables underground- found in Great Plains, ex. Edwards Aquifer, TX
   
2. pH= -log[H+]
   
3. acid rain( sulfuric acid from atmosphere) kills tree by making aluminuma dn manganese more soluble
   
4. at low pH, K+ leaches(goes to water table)
   
5. K+ is limiting(not enough) for plan, so we buy fertilizer
   
6. acid rain and low pH explain decline in forests, ex. NE Canada, Germany(Black Forests)
   

1. Graft-roots connect, may pass hormones to eachother
   
2. Root mycorrhizae- association between roots and fungi, allow more phosphorus and other minerals to enter root
   
3. Nodules- swelling on roots, filled with nitrogen-fixing bacteria, produce NA3(ammonia), found in legumes(peas, soybean, clover), nitrogen used in DNA bases, and amino acids(which are made of proteins)
   

1. Houston has clay(are small particles); problem: expands and holds water; in summer, heat dries clay, which shrinks and cracks foundation
   
2. Loam- ideal soil= 40% sand= allows drainage, 40% silt= takes up space, 20% clay=holds minerals and enough water
   
3. Clay particle has negative charge and attracts positive minerals
   
4. organic matter in soil-litter, droppings, decomposing humans (these dead materials help soil hold water
   

1. carbon-from air
   
2. hydrogen-from water
   
3. oxygen-from water
   
4. N, P, K, S, Ca, Mn- dissolves ions in soil
   

1. needed in agricultural soils
   
2. replace the removed minerals
   
3. inorganic-ex. fertilizer-short lasting, fast acting
   
4. organic-ex. manure or bone meal-long lasting, slow acting
   
5. fertilizer numbers: 10-20-20 = 10%Nitrogen, 20%Phosphorus, 20% Potassium