Biology · Morphology of Flowering Plants · NEET
A tap root develops from the radicle of the embryo. It grows straight down as one thick primary root and gives off smaller lateral (secondary) roots. Mustard shows a tap root system and it is seen in dicots. A fibrous root system forms when the primary root dies early and is replaced by many thin roots of about equal size. These roots come out from the base of the stem. Wheat shows a fibrous root system and it is seen in monocots. For NEET, remember: tap = one main root from radicle; fibrous = many roots from stem base.
Yes. Fibrous roots do not grow from the radicle. They grow from the base of the stem, which is a part other than the radicle. So by definition they are adventitious. But in NEET questions the two words are used in different ways. "Fibrous" describes the SHAPE and system (many thin equal roots in monocots like wheat). "Adventitious" describes the ORIGIN (any part that is not the radicle). If a question asks about grass, Monstera or banyan, the expected answer is adventitious. If it asks about the wheat root system, the expected answer is fibrous.
Only the tap root arises from the radicle. The radicle is the embryonic root inside the seed. When the seed germinates, the radicle grows out and becomes the primary root, which is the tap root. Fibrous and adventitious roots do NOT come from the radicle. This is a favourite NEET point: "root from radicle = tap root."
They are called fibrous roots. In monocots like wheat, the primary root (from the radicle) is short-lived and is replaced by many roots that arise from the base of the stem. These together form the fibrous root system. NEET 2020 asked exactly this and the answer was fibrous roots, not prop roots or lateral roots.
The hanging prop roots of the banyan tree are adventitious. NCERT lists grass, Monstera and banyan tree as examples of adventitious roots, because these roots arise from parts of the plant other than the radicle (the banyan prop roots grow down from the branches). They are not called fibrous, because fibrous is used for the monocot stem-base root system like wheat.
The roots that originate from the base of the stem are:
Sweet potato is a modified:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Yes, as a general rule. Dicots like mustard, gram and mango have a tap root system. Monocots like wheat, maize and rice have a fibrous root system. This is a common NEET one-liner, but remember some plants also have adventitious roots for special jobs.
No. Lateral (secondary) roots are the branches that come out from the main tap root. Fibrous roots are the many equal-sized roots of a monocot that come from the stem base. Lateral roots belong to the tap root system; fibrous roots do not.
NCERT gives four functions: absorption of water and minerals from the soil, anchorage (fixing the plant firmly), storage of reserve food, and synthesis of plant growth regulators. All three root types share these jobs.
Tap root: mustard. Fibrous root: wheat. Adventitious root: grass, Monstera or banyan tree. These are the exact NCERT examples, so use them in NEET.
