Question

Give one point of difference between:
(i) Tap root and adventitious root
(ii) Prop and stilt roots
(iii) Protoxylem and metaxylem
(iv) Phelloderm and periderm
(v) Vascular cambium and cork cambium

Answer 1

(i) The main difference between taproot and adventitious root is that the taproot is the main root, growing down deep into the soil, whereas the adventitious root (or fibrous root) is made up of a group of roots of similar size and similar shapes

Answer 2

Difference between:

(i) Taproot and Adventitious Root:

Taproot: Primary, long-persistent, thick, deep-rooted main root present in dicots, develops from radicle

Adventitious Root: Multiple, short-lived, thin hair-like, shallow-rooted roots present in monocots, does not develop from radicle

(ii) Prop and Stilt Roots:

Prop roots: Pillar-like long roots developing from upper horizontal part of the stem and pass down vertically, hygroscopic, thick and massive

Stilt roots: Rope-or pole-like short roots developing from basal nodes of the main stem and pass at an oblique angle to the stem, non-hygroscopic, less thick .

(iii) Protoxylem and Metaxylem:

Protoxylem: First-formed, differentiates from procambium, with narrow tracheids, non-fibrous, contains more parenchyma and fewer tracheids, matures before plant elongation

Metaxylem: Formed after protoxylem, differentiates from fascicular cambium, broad tracheids, fibrous, contains less parenchyma and more tracheids, matures after plant growth  

(iv) Phelloderm and Periderm :

Phelloderm: Innermost layer with parenchymatous tissue

Periderm: Outer layer or the bark of a plant that differentiates into phellum, phellogen, and periderm  

(v) Vascular Cambium and Cork Cambium :

Vascular Cambium: Primary meristem and along with its derivatives, secondary xylem and phloem forms the vascular tissue of the plant.

Cork Cambium: Secondary meristem and along with its derivatives, phellem and phelloderm, forms the periderm of the roots and stems of the plant.