Key out a section
"Key out a section" is a free, interactive Class 11 Biology simulation for NEET, built on the NCERT section "Dicot and monocot roots" in Anatomy of Flowering Plants. Build a transverse/vertical section feature by feature and a dichotomous key narrows it to dicot/monocot root, stem or leaf. NEET has asked about this idea 4 times in 10 years of papers.
From the lesson Monocot stem in Anatomy of Flowering Plants. Change the values and watch what happens.
What it shows
NCERT §6.2.1–6.2.6, Fig 6.3–6.5
Build a transverse/vertical section feature by feature and a dichotomous key narrows it to dicot/monocot root, stem or leaf.
Controls
5 to try
- Segmentedbundle arrangement radial / ring / scattered
- Segmentedhypodermis none / collenchyma / sclerenchyma
- Sliderxylem patches 2–12
- Segmentedpith small / large
- Togglestomata lower only / both surfaces
Try this
Set the features so the key lands on 'monocot stem', then change exactly one feature to land on 'dicot stem'.
Common mistake
Monocot stem with collenchyma hypodermis; root bundles called conjoint; monocot root with 2–4 xylem.
In NEET
10 years of papers
Asked 4 times in 10 years of NEET.
See the past questions: Anatomy of Flowering Plants (chapter)
The idea behind it
NCERT §6.2.4, Figure 6.4
- Hypodermis is made of sclerenchyma, not collenchyma as in the dicot stem.
- Vascular bundles are many and scattered through the ground tissue instead of forming a ring.
- Each bundle is wrapped in a sclerenchymatous bundle sheath.
- Bundles are conjoint and closed: there is no cambium.
- Bundles near the edge are generally smaller than those near the centre.
- Phloem parenchyma is absent, and the bundles contain water-containing cavities.
- The bundles sit in a large, conspicuous ground tissue of parenchyma that fills the stem.
- Identification key: scattered, conjoint, closed bundles with sclerenchyma sheaths and no phloem parenchyma mean a monocot stem.
Questions
4 answers
- What does the "Key out a section" simulation show?
- Build a transverse/vertical section feature by feature and a dichotomous key narrows it to dicot/monocot root, stem or leaf.
- What mistake does the "Key out a section" simulation fix?
- A common mistake it clears up: monocot stem with collenchyma hypodermis; root bundles called conjoint; monocot root with 2–4 xylem.
- Has NEET asked about this idea?
- Yes. NEET has asked about this idea 4 times in 10 years of papers.
- Is this simulation free?
- Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Monocot stem" in Anatomy of Flowering Plants (Class 11 Biology).
Embed this simulation
Free, with a link back
Teaching this idea? Put the simulation on your own page or LMS with this code.