plant science - cells and growth

shoot system

aboveground

vegetative organs

leaves and stems

reproductive organs

flowers and fruits

determinate growth

max size genetically determined

• usually can’t heal/regrow

• max size rarely achieved in nature

• leaves, flowers, and fruits

indeterminate growth

no max size genetically

• usually can heal/regrow

• roots and stems

cell theory

1. all plants and animals made up of cells

2. cells basic unit of life

3. cells arise from other cells

all cells contain

cell membrane, cytoplasm, ribosome, and dna

cytosol

gel-like material organelles are suspended in

cytoskeleton

protein threads

chromatin

DNA and proteins

nucleolus

where ribosomes are made

ribosomes

responsible for protein synthesis

where are ribosomes?

floating freely or embedded in the endoplasmic reticulum

endomembrane system

modify, package, and transport lipids and proteins

vesicles and peroxisomes

bud off from endomembrane and are transport units for diverse materials

endoplasmic reticulum

modifies proteins and synthesizes lipids

golgi apparatus

sorts, tags, packages, and distributes proteins and lipids

unique eukaryotic cell components

endomembrane system, ER, golgi apparatus, mitochandria

unique plant cell components

cell wall, central vacuole, chloroplast

central vacuole

large, membrane bound (tonoplast) structure that stores water

central vacuole functions

regulating water via osmosis

stores nutrients, ions, and waste products

Chloroplast function

stores chlorophyll and pigments for photosynthesis

Chloroplast structure

pigments stored in tylakoids.

Cell wall structure

middle lamella and primary cell wall

middle lamella

thin layer of pectin binding adjacent cells

Primary cell wall composition

cellulose microfibrils bundled tghr

thin and elastic allowing for cell enlargement

Secondary cell wall

lignin is deposited tghr w/ cellulose adding rigidity

thicker than primary wall

Cell wall enlargement

the orientation of cellulose microfibrils determine direction

plasmodesmata

pores that allow for communication between cells

meristematic tissue

all plant tissues originate from and later differentiate and specialize

totipotent

plant tissue that can regenerate the entire plant

meristems

regions of continuous cell division and growth

• apical meristems

• lateral meristems

• intercalary meristems (grasses)

apical meristem

located at end of stems and roots

types of primary meristematic tissues

1. protoderm

2. ground meristem

3. procambium

who produces primary meristematic tissues

apical meristems

protoderm

gives rise to epidermis

ground meristem

gives rise to ground tissue

procambium

gives rise to vascular tissue (primary)

lateral (secondary) meristem

responsible for secondary growth (girth)

regions lateral meristem is located

vascular cambium and cork cambium

vascular cambium

gives rise to vascular tissue (secondary)

cork cambium

produces periderm

Types of meristematic tissue in embryo of a seed

ground meristem, procambium, and protoderm