plants

two main groups of plants

vascular and non-vascular

vascular plants organ systems

above ground shoot system and underground root system

shoot system

stems and leaves

leaves

grow from stems and specialized to do photosynthesis

stems

bear reproductive structures of mature plants

root system

roots; anchors plants and absorbs water/minerals

parenchyma cell structure

majority of cells w flexible thin walls and are spherical but cell walls flatten when pressed against eachother

parenchyma structure in leaves/green stems

contain many chloroplasts

parenchyma cells in roots/fruits

lack chloroplasts but have large central vacuoles that can store subs like water/starch/oils

collenchyma cells

make up long strings that can be pulled from cellery

collenchyma structure

elongated, unevenly thick cell walls that occur in long strands/cylinders

collenchyma growth

as cell grows, thin parts of cell wall expand, making cells flexible and allow plants to bend without breaking

sclerenchyma cells

have thick secondary cell walls that contain lignin, they lack cytoplasm and other living components after maturing

lignin

strong substance that makes cell walls tough

sclerenchyma growth

die once completed growth and development

sclerenchyma cell functions

provide support for mature plants

2 kinda of sclrenchyma cells

sclereids and fibres

sclereids (stone cells)

shorter than fibre, distributed randomly in plant, irreglar shape

fibres

needle shaped, thick cell walls, small interior spaces, when stacked for tough elastic tissue