Bio 2, chapter 35, Plant structure, growth and development


is a group of cells consisting of one or more cell types that together perform a specialized function


consists of several types of tissues that together carry out particular functions

3 basic plant organs

2. stems
3. leaves

they are organized into

1.root system (below ground)
2.shoot system (above ground)

root system

-take up H2O
-relies on photosynthate from the shoot system

shoot system

-relies from the roots for water
-photosynthesis happens in the leaf


-anchors the plant
-absorbs minerals and water
-stores carbohydrates

Apical buds

-primary growth (length)

axillary buds

would lie dormant, until cut off top apical bud, pruning house plants, cut off the top and they become fuller


point where the petiode of leaf connects to the steam ( between the nodes is termed internode)


2 major groups

Eudicots have

-a taproot ( the main vertical root, long and skinny)
-lateral root (branch roots that come from the taproot)

Monocots have

fibrous root which has roots that arise from the stems or the leaves, and lateral roots that arise from adventitious roots (shallow and spread out)

root hairs

-absorb the water and the minerals ( the # of root hairs increases and maximize in the surface area)

-many plants have the root adaptations with specialized functions (mangroves)

1. stabilize the soil
2. habitat for juvinales

black mangroves

dead man's fingers, snorkel roots


buttresses (take CO2 and release O2)


is an organ that consists of:
-an alternating system of nodes ( the point at which leaves are attached)
-internodes, the stem segments between nodes

axillary bud

is the structure that has the potential to form a lateral shoot or branch

apical bud

or terminal bud, is located near the shoot tip and causes elongation of a young shoot

Apical dominance

helps to maintain dormancy in most axillary buds

the leaf

is the main photosynthetic organ of most vascular plants, solar panel

leaves consists

of a flattened blade and a stalk called the petiole and the leaves to a node of the stem

the blades

have pores or holes where the gas exchange occurs in the underside of the leaf, stomata


have parallel veins


have branching veins


the outside or the "skin" of the plant

vascular system

Xylem and Phloem


moves water from the roots up, evapotransportation. water goes up agains gravityt


moves sugar from the leaves around the plant


everything else is in the middle


a waxy coat that helps preventing water loss from epidermis


in the woody plants, this is the protective tissue

plant cell types

-water-conducting cells of xylem
-sugar-conducting cells of phloem


-photosynthesize (full of chloroplasts and is found in the leaf) (P&P)
- are the least specialized
-no secondary walls

Collenchyma cells

-are grouped in strands and help support young parts of the plant shoot
- look like strings and they are found in cellery

Sclerenchyma cells

-are rigid bc of thick secondary walls
-are dead at functional maturity
2 types:
1. sclereids- are short and irregular shape w/ thick secondary walls
2. fibers- are long and slender and are arranged in threads

2 water conducting cells of the xylem

2.vessel elements
(these are dead at maturity and this is the reason they are rigid)


are elements that align end to end to form long micropipes (look like tubes)

sugar conducting cells of the phloem

1.sievie-tube elements (are alive at functional maturity, they don't have organelles)
2.sievie plates are the porous end walls that allow fluid to flow between cells along the sievie tubes

indeterminate growth

the plant grow throughout it's life is called

determinate growth

some plants cease to grow at a certain size is called


are perpetually embryonic tissue and they are allow for indeterminate growth

apical meristems

are located at the tips of the roots and shots and at the axillary buds of shoots, they are the primary growth

primary growth

length or how long is gonna be

secondary growth

width or how thick the plant is apical meristem-growth, it happens in woody plants, in their stems and roots but rarely in the leaves
-characteristic of gymnosperms and many eudicots but NEVER monocots

lateral meristems

add the thickness to woody plants and they help protect the plants from fire and they are called secondary growth.

2 lateral meristems

1. vascular cambium
2. cork cambium

vascular cambium

adds layers of vascular tissue called seconday xylem (wood) and secondary phloem

cork cambium

replaces the epidermis with periderm, which is thicker and tougher, bark protection (protection from predators, fire, etc)


complete their life cycle in a year or less


require two growing seasons


live for many years

root cap

covers the root tip, and protects the apical meristem as the root pushes through the soil

growth occurs behind the root tip, in three zones of cells

(0. root cap, protects the roots and helps them)
1. zone of cell division
2. zone of elongation
3. zone of differentiation, or maturation

leaf primordia

leaves developed from them, along with the sides of the apical meristem (bc that's where cell division occurs)


allows CO2 and O2 exchange between the air and the photosynthetic cells in a leaf

guard cells

the flanked cells on each stomatal pore, and it will regulate its opening and closing (almost looks like a moth)


the tissue that is sandwiched between the upper and lower epiderms of the leaf. is in the inside of the leaf

the vascular cambium

as the plant ages, it's diameter will be larger

to figure out the age of the tree (dendrochronology)

count the lines, and 1 line = 1 year

secondary xylem

accumulates as wood and consists of tracheids, vessel elements (only in angiosperms) and fibers

early wood

is formed in the spring and has thin cell walls to maximize the water delivery

late wood

formed late summer, thick water calls and contributes more to the stem support

cork cells

deposit waxy suberin in their walls and then they die

periderm consists of

-cork cambium
-and cork cells it produces


consists of all the tissues external to the vascular, including secondary phloem and periderm