BIO 1010 Lab 1 - Introduction to the Plant Body-1.pdf

BIO 1010 Lab 1: Introduction to the Plant Body Dolan UNCP Organs and Tissues Plants have three or four major groups of organs: Roots, Stems, Leaves, Flowers Each organ is composed of tissues. a group of cells performing a similar function. may be more than one tissue per organ. (Prop roots) 3 Root S...

BIO 1010 Lab 1: Introduction to the Plant Body Dolan UNCP Organs and Tissues Plants have three or four major groups of organs: Roots, Stems, Leaves, Flowers Each organ is composed of tissues. a group of cells performing a similar function. may be more than one tissue per organ. (Prop roots) 3 Root Structure 4 regions: 1. Root cap 2. Region of cell division 3. Region of cell elongation 4. Region of maturation Longitudinal section through root tip External Form of A Woody Twig Axil - Angle between petiole and stem Axillary Bud located in axil. Will become branches or flowers in flowering plants Bud scales protect buds. Terminal Bud at twig tip Growth makes twig longer. Number of groups of bud scale scars tells age of twig. Stipules - Paired, often leaflike appendages at base of a leaf 7 8 9 Composition Palmate venation (dicot) Pinnate venation (dicot) Parallel venation (monocot) Dichotomous venation (gymnosperm) Palisade Mesophyll Internal Leaf Anatomy Spongy Mesophyll 19 Mesophyll and Veins Monocots have some differences: Usually do not have mesophyll differentiated into palisade and spongy layers Often have bulliform cells on either side of main central vein – Bulliform cells partly collapse under dry conditions. o Causes leaf to fold or roll, reducing transpiration Monocot leaf cross section Collapsing Bulliform Cells = Rolled Blade Turgid Bulliform = Open Blade Specialized Leaves Leaves of Arid Regions limited availability of water, wide temperature ranges, and high light intensities. Leaves reduce loss of water by: Thick, leathery leaves Fewer stomata or sunken stomata Succulent, water-retaining leaves, or no leaves Dense, hairy coverings Specialized Leaves and stems of Aquatic Plants Lab Reminders View the pre-lab recording Print and Read the Lab Handout Complete the pre-lab quiz