Chapter 35 Plant Structure Study Guide Part 2 Flashcards
What is the pericycle?
Outermost cell layer in vascular cylinder
- lateral roots arise from within the pericycle
What does the endodermis do?
Regulates passage of substances from soil into vascular cylinder
What is the endodermis?
Innermost layer of the cortex
What are shoot apical meristems?
Dome shaped mass of dividing cells at the shoot tip
What does the stomata do?
Pores that allows for CO2 and O2 exchange between the air and photosynthetic cells in a leaf
What is mesophyll? What are its two layers?
Ground tissue in a leaf between upper and lower epidermis
2 layers: Palisade mesophyll and Spongy mesophyll
What is a palisade mesophyll?
Upper part of the leaf
What is a spongy mesophyll?
Lower part of the leaf; loose arrangement allows for gas exchange
What does leaves develop from?
Develops from leaf primordia along the sides of the apical meristem
What does secondary growth do?
Increases at the diameter of stems and roots in woody plants
Where can secondary growth be found?
In gymnosperms and eudicots
On a typical wood stem, where does the vascular cambium form?
Vascular cambium forms on the outside of the pith and primary xylem, and inside of primary phloem & cortex
On a typical wood root, where does the vascular cambium form?
Vascular cambium forms exterior to primary xylem and inferior to primary phloem and pericycle
What is dendrochronology?
Analysis of tree ring growth patterns and can be used to study past climate damage.
What are lenticels?
Located at the periderm and allows for gas exchange b/w living stem or root cells and the outside air
What does bark consist of?
Consists of tissues external to vascular cambium, including secondary phloem and periderm
What is growth?
An irreversible increase in size
What is morphogenesis?
Development of body form and organization
What is cell differentiation?
Process by which cells with the same genes become different from each other
What determines cell fate?
- symmetry of cell division
- distribution of cytoplasm b/w daughter cells
What is polarity?
Condition of having structural or chemical differences at opposite ends of an organization
What is preprophase band?
Ring of concentrated microtubules that predicts the future plan of the cell division
What is pattern formation?
Development of specific structures at specific locations
What are the 2 hypotheses of pattern formation?
- lineage-based Hypothesis
- population-based hypothesis
What is the lineage based hypothesis?
Proposes that cell fate is determined early in development and passed on to daughter cells
What is the population based hypothesis?
Proposes that cell fate is determined by final position
What is an example of pattern formation?
Hox genes in animals that affect the number and placement of appendages in embryos.
What is meristem identity genes?
The switching on of floral genes that triggers the transitions from vegetative growth to flowering
What is organ identity genes (plant homeotic genes)?
Regulates the development of floral pattern
What is the ABC hypothesis?
Hypothesis of flower formation that identifies how floral organ identity genes direct the formation of the four types of floral organs.
What are some characteristics of Monocots? (6 things)
- Embryos: one cotyledon
- Leaf venation: Veins usually parallel
- Stems: Vascular tissue scattered
- Roots: Root system usually fibrous (no main root)
- Pollen: Pollen grain with one opening
- Flowers: Floral organs usually in multiples of 3
What are some characteristics of eudicots?
- Embryos: two cotyledon
- Leaf venation: Veins usually netlike
- Stems: Vascular tissue arranged in a ring
- Roots: Root system has a main root (taproot)
- Pollen: Pollen grain with 3 opening
- Flowers: Floral organs usually in multiples of4 or 5
