Tree Biology

• The xylem is responsible for the transport of water & minerals
• In trees, division of cells occurs in specialized zones called meristems.
• After division, cells undergo differentiation to become specialised for their function.
• Root hair cells are involved in absorbing nutrients from soil.
• Cells with similar structure and function are arranged into tissues.
• Parts of a tree

  A) foliage

  B) branches

  C) top

  D) crown

  E) branch

  F) twig

  G) limb

  H) bole

  I) radicle

  J) trunk

  
• The organs that make up a tree are: leaves, stems, roots, flowers, fruit
• Meristems have two types of growth: primary and secondary.
• Primary meristem growth produces cells that result in elongation of shoots and roots.
• The growth of shoots and roots are from the apical meristems (tips).
• Secondary growth produces cells that result in increase in diameter.
• What produces cells that result in increase in diameter.

  Secondary meristem growth
• What two types of secondary meristem growths are there?

  Vascular cambium and cork cambium
• Secondary growth of meristems produce wood allowing trees to grow large
• Palms lack secondary growth meristems
• Where are apical meristems located?

  at the end of shoots and roots
• what does this diagram show?

  A) Apical meristem

  B) root cap

  
• root cap is the part of the root that is elongating and growing into the soil
• two types of vascular tissues: Phloem and Xylem
• Fill in the diagram:

  A) Sapwood

  B) Heartwood

  C) Growth Ring

  D) Pith

  E) Vascular Cambium

  F) Cork Cambium

  G) Bark

  
• Phloem distributes sugars and nutrients made in the shoots
• Xylem distributes water and minerals taken up by the roots
• The Vascular Cambium is a thin sheath of dividing cells that become the vascular system of the tree
• what is a vascular cambium?

  a thin sheath of dividing cells
• the vascular cambium produces 2 kinds of tissues: xylem (inside), phloem (outside)
• the cork cambium (phellogen) produces the bark (periderm)
• the cork cambium (phellogen) produces the bark (periderm)
• the cell wall is made of cellulose and lignin
• cellulose is the structural component of a cell wall
• lignin is the strength and rigidity of the cell wall of plants
• what are the four functions of xylem?

  Conducts water and dissolves minerals. Supports the weight of the tree. Stores carbohydrates reserves. Defends against the spread of disease/ decay.
• Symplasm is living tissue (i.e. sapwood)
• Apoplasm is non-living tissue (i.e. heartwood)
• Fill in the diagram:

  A) tracheid

  B) fibers & parenchyma

  C) start of season

  D) ray cell

  E) spring/ older

  F) fall/ newer

  
• Xylem in Gymnosperms (Conifers) have: tracheids, fibers, and parenchymas.
• tracheids conducts water and provide mechanical support in xylem
• fibers provide mechanical strength in xylem
• what is the function of tracheids?

  conducts water and provide mechanical support
• parenchyma are living cells interspersed among other xylem cells, store carbohydrates, defend against decay, and have a structural function in xylem
• what are the four functions of parenchyma?

  living cells interspersed among other xylem cells. store carbohydrates. defend against decay. have a structural function in xylem