1. SEEDS, TISSUES, ORGAN MODIFICATIONS
91.4 – 91.7
SEEDS, TISSUES, ORGAN MODIFICATIONS

2. SEEDED VASCULAR PLANTS
GYMNOSPERMS – SEEDS THAT DO NOT DEVELOP WITHIN AN ENCLOSED STRUCTURE (EVERGREENS)
ANGIOSPERMS – SEEDS THAT DEVELOP WITHIN A PROTECTIVE STRUCTURE (FLOWERING PLANTS)
3 BASIC TISSUE TYPES
1) DERMAL –OUTER PROTECTIVE COVERING
(ARIL) TO PREVENT WATER LOSS &
PROTECT AGAINST PHYSICAL AGENTS &
PATHOGENIC ORGANISMS

3. 2) GROUND – CONSISTS MOSTLY OF THIN- WALLED CELLS THAT FUNCTION IN STORAGE, PHOTOSYNTHESIS, SUPPORT, AND SECRETION 3) VASCULAR - XYLEM & PLOEM CARRY OUT CONDUCTION OF WATER, MINERALS, NUTRIENTS, & GIVES SUPPORT

4. 4) ALL 3 TYPES OF TISSUE ARE DERIVED FROM MERISTEMATIC TISSUE CALLED INITIALS & ONCE DIFFERENTIATED, THEY ARE CALLED DERIVATIVES

5. PLANT ORGAN MODIFICATION

6. STORAGE ROOTS

7. BULBS – STEMS GROW UNDERGROUND
VERTICALLY CONSISTING OF ENLARGED
BASES OF LEAVES (ONION)
TENDRILS

8. STEM TUBERS –MODIFIED STEMS FOR FOOD STORAGE & CAN FORM ROOTS BY BUDDING OFF STEM

9. LEAF MODIFICATIONS
spines

11. MERISTEM

12. AUXINS & PHOTOTROPISM

14. Phytochrome is a photoreceptor, a pigment that plants use to detect light. It is sensitive to light in the red and far-red region of the visible spectrum. Many flowering plants use it to regulate the time of flowering based on the length of day and night (photoperiodism) and to set circadian rhythms. It also regulates other responses including the germination of seeds, elongation of seedlings, the size, shape and number of leaves, the synthesis of chlorophyll, and the straightening of the epicotyl or hypocotyl hook of dicot seedlings. It is found in the leaves of most plants.
Biochemically, phytochrome is a protein with a bilin chromophore.