module 9

• botany

  the branch of science that deals with plants, the person who studies plant structure and function is called botanist
• histology

  the science that deals with tissues and the person who studies this
• plant tissue

  -protective tissue

  -meristematic tissue

  -mechanical tissue

  -conducting tissue

  -specialized tissue
• protective tissue

  covers the surface of the leaves and the living cells of the roots and stems
• protective tissue

  -epidermis

  -periderm
• epidermis

  the protective covering is the skin whereas in plant called
• periderm

  also called bark, which replaces the epidermis in plants that undergo secondary growth
• vertical growth

  as new cells form in the meristems, the roots and shoots will increase in length
• three types of primary meristems

  -protoderm

  -ground meristems

  -procambium
• lateral meristems

  accounts for the secondary growth in plants which is generally the horizontal growth in plants which is generally the horizontal growth
• vascular cambium

  which is sometimes called cambium.

  it is a thin, branching cylinder, except for the tips where apical meristems run the length of the roots and stems of most perennial plants and many herbaceous plants
• cork cambium

  it is thin cylinder that runs the length of roots and stems
• intercalary meristems

  which were found in grasses and related plants that do not have vascular cambium or cork cambium, as they do not increase in girth
• these plants do have apical meristems and in areas of leaf attachment called node
• mechanical tissue

  are responsible in synthesizing organic compounds, supporting and providing storage for the plant
• three cells that complete ground tissue

  -parenchyma

  -collenchyma

  -sclerenchyma
• parenchyma cells

  are the most abundant of the cell types and found in almost all major parts of higher plants
• chlorenchyma

  some parenchyma cells have many chloroplasts and form the tissues found in the leaves
• aerenchyma tissue

  some groups of cells are loosely packed together with connected air spaces such as water lilies
• collenchyma

  are found beneath the epidermis and generally, they are elongated and their walls are pliable in addition to being strong
• sclerenchyma tissue

  these cells have thick tough secondary walls that are imbedded with lignin
• sclereids

  which are randomly distributed throughout other tissues

  also called stone cells
• in vascular plants, conducting tissues are xylem and phloem
• xylem

  -is the tissue that conducts the sap obtained by absorption of water and minerals by roots

  -it conduct water and minerals from roots to the other plant organs
• phloem

  are tissues that conduct the sap containing water and amino acids and sugar, especially sucrose, obtained by photosynthesis
• metabolite translocation is powered by osmotic pressure
• Stomata is microscopic pore on the surface (epidermis) of land plants. It is surrounded by a pair of specialized epidermal cells called guard cells,
• guard cells -

  which act as turgor- driven valve that opens and closes the pores in response to given environmental conditions. Stomata is usually located underside of the leaf.
• Water vapor is also released into the atmosphere through these pores in the process called transpiration.
• Trichomes are cutinized epidermal appendages found in the leaf, stem, flower and fruit functioning for protection and prevention of water evaporation. It may be unicellular and multicellular.
• meristems

  is the region that produce new cell