BOT 14 | 2ND LAB LE

Lignin

A heterogeneous polymer of phenolic compounds that makes cell walls rigid, impermeable to pathogens, and hard for herbivores to masticate

Idioblasts

Specialized "crazy cells" that protect against herbivory by possessing toxic chemicals or sharp crystals

Silica cells

Type of idioblast found in grasses and sedges that gives strength and rigidity to young blades to deter herbivores

Thorns

Modified branches used for physical defense

Spines

Modified leaves used for physical defense

Prickles

Epidermal outgrowths emerging from non-nodal parts

Batesian mimicry

A type of mimicry where a harmless species pretends to be harmful to avoid being eaten (e.g., Lithops)

Endosymbiosis

Symbiotic relationship where one symbiont lives inside the tissues of the other

Root nodules

Swellings on the roots of legumes (e.g., Mimosa pudica) that house nitrogen-fixing bacteria (Rhizobium)

Azolla

Cavities in the leaves of this aquatic fern accommodate the cyanobacteria Anabaena azollae

Velamen

Specialized thick, multilayered, suberized epidermis on orchid roots for efficient water uptake and protection

"Water tank" structure

Anatomical adaptation of Bromeliads used to catch and store rainwater

Haustoria

Specialized structures in parasitic plants used to exploit the host for water and nutrients

Uredospores

Asexual spores of Puccinia (wheat rust) released through the host's ruptured epidermis

Terpenes/Terpenoids

The largest group of secondary metabolites, composed of 5-C isoprene units

Phenolics

Class of compounds consisting of a benzene ring with at least one hydroxyl group

known for antioxidative properties

Alkaloids

Bitter, toxic alkaline compounds containing at least one nitrogen atom (e.g., Caffeine, Morphine)

Infusion

Preparation method involving steeping plant parts in a liquid (like oil or water) without continuous boiling

Decoction

Preparation method involving boiling plant parts in water to extract active substances

Fibers

Elongated cells with very thick secondary walls and interlocking tapered ends

Bast or Soft fibers

Type of fiber found in clusters of phloem in the inner bark of dicot stems

Latex

Sticky, white, lipid-soluble exudate produced in laticifers that coagulates upon exposure to air

Resin

Viscous, yellowish-to-brown lipid-soluble liquid produced in canals or cavities

fossilized form is amber

Mucilage

Hydrophilic polysaccharide exudate that forms a viscous solution with water

found in Okra and Hibiscus

Transverse (Cross) section

Wood section cut perpendicular to the long axis

shows growth rings as circles and rays as lines

Radial section

Wood section cut along the radius (pith to bark)

shows rays lengthwise

Tangential section

Wood section cut at a right angle to the radius

shows rays as short vertical line