primary growth in plants

Identify the three zones of primary growth within the root

zone of cell division- new cells are produced through mitosis from meristematic cells

zone of cell elongation- as new cells enlarge, this pushes the root tip forward

newly created, immature cells elongate and grow to their functional size

zone of cell differentiation- new cells are undifferentiated (not specialized)

cells mature, developing physical and physiological characteristics necessary to perform their specialized functions in root

which root tissue arises from procambium

epidermis

which root tissue arises from ground meristem

cortex and endodermis

which root tissue arises from protoderm

vascular tissues and pericycle

describe different root tissues, arrangement and their function in a typical eudicot root

epidermis- protective skin of root

cortex- bulk of root tissues

endodermis- specialized tissue that filters substance absorbed by the root

vascular tissue- located in the central part of the root, transports water and nutrients

pericycle- located in central part of root, provides structure support and protects vascular tissues

outline general purpose and function of large vs fine roots

large: provide support against gravity, wind, bulk flow of water

fine: actively engaged in the uptake of water and minerals

how do roots sense gravity

special gravity-sensing cells in the root caps called statocysts- contain statoliths

weight of statoliths allow them to settle with gravity inside a statocyst

Identify the three zones of primary growth within the shoot

zone of cell division- at apex of plant where new cells are produced by the meristematic cells of SAM

zone of cell elongation- cells enlarge and grow to their functional size

zone of cell differentiation- cells develop and mature acquiring the physical and physiological characteristics necessary to perform specialized functions for diff tissues of the shoots

protoderm in shoot

epidermis

ground meristem in shoots

parenchyma

procambium in shoots

produce discrete bundles or strands of vascular tissues

describe different stem tissues, arrangement, and function in a typical eudicot root and monocot stems

Epidermis: protective tissue, covered in cuticle to prevent water loss, has stomata for gas exchange 

Parenchyma: function as structural, storage, or photosynthetic tissue 

Pith parenchyma: determines length of internode 

Leaf mesophyll: functions in photosynthesis 

Primary phloem: transport of sugars and hormones 

Primary xylem: transport of water and minerals

Sclerenchyma: structurally supportive tissue; thickens cell walls 

Pith: structural and storage tissue 

Support, transports nutrients, provide mechanical support to stem

Vascular bundles: other important tissues! 

• conjoint (xylem and phloem on the same radius, as in stems and leaves)

• radial (xylem and phloem on different radii, as in roots)

• concentric (one tissue surrounding the other)

identify phytomer

simple repeating units of a leaf plus its axillary bud and stem below- consists node and internode

how is the phyllotaxis of leaves determined

by SAM, growth tip of the plant, which coordinates leaf arrangement through auxin and other genetic and hormonal signals