See NEET Concepts Come Alive
ArivoliAI NEET Lab — a free NEET preparation app for Physics, Chemistry & Biology.
A complete, free NEET prep app — AI-guided learning, chapter-wise MCQs and timed mock tests, plus interactive, animated Visual Labs that turn tough topics like ray optics, atomic structure and the cardiac cycle into something you can see. Learn in தமிழ், हिंदी or English. Try live labs below across all three subjects — 100% free, fully offline after install, no account.
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NEET Lab
Interactive Physics, Chemistry & Biology models
Tap parts, watch them move, and learn — right below. 👇
Try our Visual Labs — Physics, Chemistry & Biology.
These are interactive labs from NEET Lab, spanning all three NEET subjects. Pick one and tap any part to learn what it does in plain English plus an exam-accurate NEET note, or hit Guided tour to be walked through it step by step.
Human Heart
Circulatory system
Selected structure
Human Heart
The human heart is a fist-sized muscular pump with four chambers. It runs a double loop: the right side sends oxygen-poor blood to the lungs, and the left side pumps oxygen-rich blood to the whole body. Tap any part, or take the guided tour.
NEET note
▸ All structures & functions
- Vena Cava
- Two large veins that drain used, oxygen-poor blood from the whole body back into the heart.
- NEET:Superior & inferior vena cava return deoxygenated blood to the right atrium.
- Right Atrium
- The top-right chamber. It collects oxygen-poor blood arriving from the body.
- NEET:Receives deoxygenated blood via the vena cava and passes it to the right ventricle.
- Tricuspid Valve
- A one-way door between the right chambers that stops blood flowing backward.
- NEET:Right atrioventricular valve; prevents backflow from the right ventricle to the right atrium.
- Right Ventricle
- Pumps the oxygen-poor blood the short distance to the lungs to pick up oxygen.
- NEET:Pumps deoxygenated blood into the pulmonary artery toward the lungs.
- Pulmonary Artery
- Unlike most arteries, the pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.
- NEET:Carries deoxygenated blood from the right ventricle to the lungs — the exception to arteries carrying oxygenated blood.
- Pulmonary Veins
- Bring fresh blood from the lungs back to the heart — the exception to veins carrying oxygen-poor blood.
- NEET:Carry oxygenated blood from the lungs to the left atrium — the exception to veins carrying deoxygenated blood.
- Left Atrium
- The top-left chamber. It collects fresh, oxygen-rich blood returning from the lungs.
- NEET:Receives oxygenated blood from the lungs via the pulmonary veins.
- Bicuspid (Mitral) Valve
- A one-way door between the left chambers, keeping blood moving forward.
- NEET:Left atrioventricular (mitral) valve; prevents backflow from the left ventricle to the left atrium.
- Left Ventricle
- The strongest chamber — it pumps oxygen-rich blood out to the entire body.
- NEET:Thickest muscular wall; pumps oxygenated blood into the aorta to the whole body.
- Aorta
- The body's largest artery — the main highway carrying fresh blood out to everywhere.
- NEET:Largest artery; carries oxygenated blood from the left ventricle to the whole body.
- Septum
- The wall down the middle that keeps fresh and used blood from mixing.
- NEET:Muscular partition separating the left and right sides of the heart.
Neuron
Nervous system
Selected structure
Neuron
A neuron is a nerve cell — the wire of your nervous system. It picks up signals with its branches, then fires a tiny electrical pulse down a long cable to pass the message on. Tap any part, or take the guided tour.
NEET note
▸ All structures & functions
- Dendrites
- Branch-like antennae that receive incoming messages from other neurons.
- NEET:Receive signals and conduct impulses toward the cell body.
- Cell Body (Soma)
- The main body of the cell — its control centre, holding the nucleus.
- NEET:Cell body (perikaryon); integrates inputs and keeps the neuron alive.
- Nucleus
- The cell's control room, storing its DNA and directing its activity.
- NEET:Contains the genetic material and controls the neuron's activity.
- Axon
- A long cable that carries the electrical message away from the cell to its far end.
- NEET:Conducts the nerve impulse (action potential) away from the soma.
- Myelin Sheath
- Fatty insulation wrapped around the axon that makes signals travel much faster.
- NEET:Electrically insulates the axon and increases the speed of impulse conduction (saltatory conduction).
- Node of Ranvier
- Tiny gaps in the insulation where the signal leaps ahead to speed things up.
- NEET:Gaps between adjacent myelin sheaths where the action potential is regenerated; they enable saltatory conduction.
- Axon Terminals
- The end of the line — where the neuron hands the signal to the next cell.
- NEET:Release neurotransmitters into the synapse to pass on the signal.
- Synapse
- A tiny gap where neurons 'talk' by sending chemical messengers across.
- NEET:Synaptic cleft; neurotransmitters diffuse across to the next cell.
DNA Helix
Molecular biology
Selected structure
DNA Helix
DNA is the instruction manual inside every cell. It looks like a twisted ladder — a 'double helix'. The outer rails are the sugar–phosphate backbone; the rungs are pairs of chemical letters (A, T, G, C) projecting inward that spell out your genes. Tap a concept, or take the guided tour.
NEET note
▸ All structures & functions
- Double Helix
- DNA is shaped like a twisted ladder — two strands wound around each other.
- NEET:Two antiparallel strands coil into a right-handed double helix (Watson–Crick model).
- Sugar–Phosphate Backbone
- The two outer side-rails of the ladder, made of sugar and phosphate, that hold the strands together.
- NEET:Sugar–phosphate backbone forms the outer rails; the two strands run antiparallel (5'→3' and 3'→5').
- Nitrogenous Bases
- The 'letters' of the genetic code — A, T, G and C — that project inward from the rails to form the rungs.
- NEET:Nitrogenous bases point inward and pair up as the rungs: purines (A, G) and pyrimidines (T, C).
- A–T Base Pair
- Adenine always pairs with Thymine — like two puzzle pieces that only fit each other.
- NEET:Adenine pairs with Thymine via 2 hydrogen bonds (complementary base pairing).
- G–C Base Pair
- Guanine always pairs with Cytosine, held together a little more tightly.
- NEET:Guanine pairs with Cytosine via 3 hydrogen bonds — stronger than A–T.
- Hydrogen Bonds
- Weak 'rungs' in the middle hold the two bases together — weak enough to unzip when DNA is copied.
- NEET:Hydrogen bonds between complementary bases: 2 for A–T, 3 for G–C.
Convex Lens
Ray optics
Selected structure
Convex Lens
A convex (converging) lens is thicker in the middle and bends parallel light inward to a single point. With the object placed beyond 2F, the two principal rays cross on the far side to form a real, inverted, diminished image. Tap any part, or take the guided tour.
NEET note
▸ All structures & functions
- Convex Lens
- A piece of glass that is thicker in the middle and bends parallel light rays inward so they meet at a point.
- NEET:A convex (converging) lens refracts parallel rays to meet at the principal focus; it has a positive focal length.
- Principal Axis
- The straight reference line running through the centre of the lens, at right angles to it.
- NEET:Principal axis: the line through the centres of curvature of the two surfaces, passing through the optical centre.
- Optical Centre (O)
- The exact middle of the lens — a ray aimed at it passes straight through without bending.
- NEET:Optical centre (O): a ray through it travels undeviated; all object and image distances are measured from O.
- Principal Focus (F)
- The point where rays coming in parallel to the axis meet after passing through the lens. There is one on each side.
- NEET:Principal focus (F): where parallel rays converge. 2F lies at twice the focal length and marks the image-formation cases.
- Object
- The upright arrow whose image the lens forms — here placed beyond 2F₁ on the left.
- NEET:Object beyond 2F₁: the case shown here, which produces a real, inverted and diminished image.
- Refracted Rays
- The two key rays — one parallel to the axis, one through the centre — that the lens bends together to fix the image.
- NEET:The ray parallel to the axis refracts through F; the ray through O passes straight. Their intersection locates the image.
- Real Image
- Where the bent rays actually cross and form a picture you could catch on a screen — upside-down and smaller here.
- NEET:Real, inverted and diminished image formed between F₂ and 2F₂ on the far side of the lens (object beyond 2F₁).
Bohr Atom
Atomic structure · 3D
Selected structure
Bohr Atom
The Bohr model pictures the atom as a tiny, dense nucleus of protons and neutrons, orbited by electrons in fixed shells. Shown here is sodium (Na): 11 protons and 12 neutrons in the nucleus, with 11 electrons arranged 2, 8, 1 across the K, L and M shells. Drag to rotate the atom in 3D, scroll to zoom, tap any part, or take the guided tour.
NEET note
▸ All structures & functions
- Nucleus
- The tiny, dense core at the centre holding almost all the atom's mass and its positive charge.
- NEET:Nucleus: contains the protons and neutrons (nucleons); carries the atom's entire positive charge and ~99.9% of its mass.
- Protons
- Positively charged particles packed in the nucleus — their number decides which element it is.
- NEET:Protons (+1 each): 11 in sodium. The atomic number Z = number of protons = 11.
- Neutrons
- Neutral particles in the nucleus that add mass but no charge.
- NEET:Neutrons (no charge): 12 in this Na-23 atom. Mass number A = protons + neutrons = 11 + 12 = 23.
- Electrons
- Negatively charged particles that occupy permitted, fixed energy levels (shells) around the nucleus.
- NEET:In Bohr's model, electrons occupy permitted stationary orbits (shells) of definite energy. Each carries −1 charge; sodium's 11 electrons fill them as 2, 8, 1 (K, L, M).
- K Shell (n=1)
- The innermost orbit, closest to the nucleus — it fills first and holds up to 2 electrons.
- NEET:K shell (n = 1): maximum 2 electrons (2n² = 2); lowest energy, filled first.
- L Shell (n=2)
- The second orbit out — it holds up to 8 electrons and is completely full in sodium.
- NEET:L shell (n = 2): maximum 8 electrons (2n² = 8); fully filled in sodium.
- M Shell (n=3)
- The third orbit — in sodium it carries just one electron.
- NEET:M shell (n = 3): holds sodium's single outermost electron; capacity 18 (2n²) but only 1 is present here.
- Valence Electron
- The lone outer-shell electron — the one sodium easily loses to become a positive ion.
- NEET:Valence electron: sodium's single M-shell electron, readily lost to form Na⁺ with electrovalency +1, which accounts for sodium's high reactivity.
Each lab has its own page with a full, part-by-part reference. The NEET Lab Android app adds many more Visual Labs and MCQ practice, and works offline after installation.
Interactive NEET diagrams & visual labs
Every Visual Lab has its own page — an interactive, tappable model with a plain-English and exam-accurate reference for each part. Explore them free, then get the app for many more.
Also available in தமிழில் and हिन्दी में.
Full NEET topic revision — notes, tables, doubts & recall
Deep, exam-grade revision pages built from the NEET Lab app content, in English, Tamil & Hindi.
Human Heart
The human heart is a fist-sized muscular pump with four chambers. It runs a double loop: the right side sends oxygen-poor blood to the lungs, and the left side pumps oxygen-rich blood to the whole body. Tap any part, or take the guided tour.
Open the interactive labNeuron
A neuron is a nerve cell — the wire of your nervous system. It picks up signals with its branches, then fires a tiny electrical pulse down a long cable to pass the message on. Tap any part, or take the guided tour.
Open the interactive labDNA Helix
DNA is the instruction manual inside every cell. It looks like a twisted ladder — a 'double helix'. The outer rails are the sugar–phosphate backbone; the rungs are pairs of chemical letters (A, T, G, C) projecting inward that spell out your genes. Tap a concept, or take the guided tour.
Open the interactive labConvex Lens
A convex (converging) lens is thicker in the middle and bends parallel light inward to a single point. With the object placed beyond 2F, the two principal rays cross on the far side to form a real, inverted, diminished image. Tap any part, or take the guided tour.
Open the interactive labBohr Atom
The Bohr model pictures the atom as a tiny, dense nucleus of protons and neutrons, orbited by electrons in fixed shells. Shown here is sodium (Na): 11 protons and 12 neutrons in the nucleus, with 11 electrons arranged 2, 8, 1 across the K, L and M shells. Drag to rotate the atom in 3D, scroll to zoom, tap any part, or take the guided tour.
Open the interactive labWhat's inside NEET Lab.
NEET Lab is a full NEET preparation app for Physics, Chemistry and Biology — AI-guided learning, MCQ practice and timed mock tests, with interactive Visual Labs as its standout feature. The demo above shows the Labs; here's everything inside the app.
AI Super 6 Mode
Learn each concept from six angles — Understand, Visualise, Mind Map, Differentiate, Doubts and Recall — to build real understanding, not rote memorising.
Chapter-wise MCQs
Practice NEET questions for Physics, Chemistry and Biology, chapter by chapter, with instant answer validation and clear explanations.
Timed Mock Tests
Sit exam-style mock tests that build speed, accuracy, time management and question-solving confidence before the real NEET.
Interactive Visual Labs
See ray optics, atomic structure, the cardiac cycle and more come alive through interactive Physics, Chemistry and Biology simulations.
NEET Formula & Revision
Quickly revise key formulae and important points with focused revision tools built for last-minute NEET prep.
Free, Offline & Multilingual
Completely free and ad-supported, works offline after installation, needs no account, and available in Tamil, Hindi and English.
Interactive, offline, and genuinely free.
NEET Lab focuses on interactive concept visualization rather than relying only on static diagrams, notes and MCQ practice — built around understanding, not memorising.
Interactive, not static
Tap structures and watch processes — a beating heart, a firing neuron, a spinning DNA helix, and Physics and Chemistry simulations — not just flat diagrams.
Completely free
Every Visual Lab and MCQ set is free. No subscription, no paywall, no in-app payments. It is ad-supported, and that is it.
Works offline
Visual Labs and learning content work offline after installation — no internet or mobile data needed to study.
No account needed
No sign-up or login required. Open the app and start learning in seconds.
How it compares
A quick, honest look at NEET Lab next to a typical NEET app.
| Feature | NEET Lab | Typical NEET app |
|---|---|---|
| Interactive animated Visual Labs | Yes — tap & watch | Static images / PDF |
| Subjects | Physics, Chemistry & Biology | Varies |
| Price | Completely free | Freemium / subscription |
| Works offline | After installation | Often needs internet |
| Account / sign-up | Not required | Often required |
| In-app payments | None | Common |
| Focus | Understanding & retention | MCQ drilling |
"Typical NEET app" describes a general pattern across popular apps and is provided for context, not a claim about any specific product.
Questions about NEET Lab
Is NEET Lab free?
Yes — it is completely free. NEET Lab by ArivoliAI is a free, ad-supported Android app. There is no subscription, no paywall, and no payment of any kind. Every Visual Lab and MCQ set is available at no cost.
What makes NEET Lab different from other NEET apps?
NEET Lab is a complete NEET preparation app that combines AI-guided concept learning (AI Super 6 Mode), chapter-wise MCQ practice and timed mock tests with interactive, animated Visual Labs for Physics, Chemistry and Biology. Rather than relying only on static diagrams and notes, you also explore concepts, experiments and processes visually. It is completely free, works offline after installation, needs no account, and supports Tamil, Hindi and English.
Does NEET Lab work offline?
Yes. The Visual Labs and learning content work offline after installation — no internet connection or mobile data is needed to study, so you can revise anywhere.
Do I need to create an account to use it?
No. There is no sign-up, login or account required — you install the app and start learning instantly.
Which subjects and topics does NEET Lab cover?
NEET Lab covers Physics, Chemistry and Biology through interactive Visual Labs, along with lab-based and concept-based MCQ practice. The interactive browser demo on this page includes labs across all three subjects — the convex lens and image formation (Physics), the Bohr model of the atom (Chemistry), and the human heart, the neuron and the DNA double helix (Biology).
Does NEET Lab have MCQ practice and mock tests?
Yes. Alongside the Visual Labs, NEET Lab includes chapter-wise MCQ practice for Physics, Chemistry and Biology with immediate answer validation and explanations, plus timed mock tests that reproduce exam-style conditions to build speed, accuracy and time management.
Which languages does NEET Lab support?
NEET Lab supports Tamil (தமிழ்), Hindi (हिंदी) and English, so you can learn NEET Physics, Chemistry and Biology in the language you are most comfortable with.
Is NEET Lab useful for NEET preparation?
Yes. NEET Lab is a full NEET preparation app aligned to the latest NEET syllabus. AI Super 6 Mode, chapter-wise MCQs and mock tests build exam readiness, while the interactive Visual Labs help you understand structures, processes and concepts that are hard to grasp from text alone.
What devices are supported?
NEET Lab is available for Android on Google Play. It is lightweight and designed to run smoothly, including offline, on everyday Android phones.
Start learning NEET Physics, Chemistry & Biology visually — for free.
Download NEET Lab on Android — a free NEET preparation app with AI-guided learning, chapter MCQs, timed mock tests and interactive Visual Labs for Physics, Chemistry and Biology. Works offline, no account.
Get it on Google Play