Class 11 common misconceptions

Does a shared genus mean the same species? — Tempting mistake: “Two organisms with the same genus name belong to the same species.”

1 worked visual example · 3 “If your child says…” checks

Can a virus multiply on nutrient medium by itself? — Tempting mistake: “A virus grows on nutrient agar like bacteria.”

1 worked visual example · 6 “If your child says…” checks

Do seed plants need flowers to make seeds? — Tempting mistake: “A pine produces spores only because it has no flowers.”

1 worked visual example · 6 “If your child says…” checks

Do wings and a streamlined shape make bats and birds one animal class? — Tempting mistake: “A bat belongs in the same animal class as birds because both fly with wings.”

1 worked visual example · 8 “If your child says…” checks

Do roots only absorb water? — Tempting mistake: “A root can only take up water and minerals.”

1 worked visual example · 8 “If your child says…” checks

Does phloem always carry sugars downward? — Tempting mistake: “Food moves down through phloem in every plant.”

1 worked visual example · 5 “If your child says…” checks

Can an organ be made of just one tissue type? — Tempting mistake: “The stomach is made entirely of muscle because it squeezes food.”

1 worked visual example · 7 “If your child says…” checks

Can cells without a nucleus make proteins? — Tempting mistake: “A bacterium has no ribosomes because it lacks a nucleus.”

1 worked visual example · 7 “If your child says…” checks

Are all enzymes proteins? — Tempting mistake: “Every biological catalyst must be a protein.”

1 worked visual example · 8 “If your child says…” checks

Does DNA replication double the chromosome count immediately? — Tempting mistake: “After S phase a cell has twice as many chromosomes.”

1 worked visual example · 7 “If your child says…” checks

Does doubling light always double the rate of photosynthesis? — Tempting mistake: “If light intensity doubles, the rate of photosynthesis must double at every light level.”

1 worked visual example · 8 “If your child says…” checks

Do plants only respire at night? — Tempting mistake: “Photosynthesis replaces respiration in daylight.”

1 worked visual example · 8 “If your child says…” checks

Does growth mean only getting bigger? — Tempting mistake: “A bigger plant organ always has more cells.”

1 worked visual example · 8 “If your child says…” checks

Is moving air into the lungs the same as cellular respiration? — Tempting mistake: “Breathing air into the lungs is cellular respiration.”

1 worked visual example · 8 “If your child says…” checks

Do arteries always carry oxygenated blood? — Tempting mistake: “Every artery carries oxygen-rich blood.”

1 worked visual example · 8 “If your child says…” checks

Is everything filtered by the kidney lost in urine? — Tempting mistake: “All filtered glucose ends up in urine.”

1 worked visual example · 8 “If your child says…” checks

Do muscles push bones to move them? — Tempting mistake: “The biceps pushes the forearm up.”

1 worked visual example · 8 “If your child says…” checks

Is every synapse a continuous electrical wire? — Tempting mistake: “An impulse jumps directly between cells at a chemical synapse.”

1 worked visual example · 8 “If your child says…” checks

Does a hormone affect every cell it reaches? — Tempting mistake: “Insulin acts on all cells equally because blood carries it everywhere.”

1 worked visual example · 8 “If your child says…” checks

Do equal masses contain equal numbers of molecules? — Tempting mistake: “18 g of water and 18 g of CO₂ contain the same number of molecules.”

1 worked visual example · 8 “If your child says…” checks

Is an orbital a path drawn around the nucleus? — Tempting mistake: “An electron travels on the line shown for its orbital.”

1 worked visual example · 8 “If your child says…” checks

Does an atom get bigger as electrons are added across a period? — Tempting mistake: “A chlorine atom is larger than a sodium atom because it has more electrons.”

1 worked visual example · 8 “If your child says…” checks

Do polar bonds always give a polar molecule? — Tempting mistake: “CO₂ is polar because its C=O bonds are polar.”

1 worked visual example · 8 “If your child says…” checks

Does an exothermic reaction always proceed spontaneously? — Tempting mistake: “A negative enthalpy change alone guarantees spontaneity.”

1 worked visual example · 8 “If your child says…” checks

Does chemical equilibrium mean the reactions stop? — Tempting mistake: “The forward and reverse reactions stop at equilibrium.”

1 worked visual example · 8 “If your child says…” checks

Can something be oxidised without oxygen? — Tempting mistake: “Sodium cannot be oxidised in a reaction with chlorine because there is no oxygen.”

1 worked visual example · 8 “If your child says…” checks

Does bond breaking always split the electrons evenly? — Tempting mistake: “When a C–Cl bond breaks, each atom always gets one shared electron.”

1 worked visual example · 8 “If your child says…” checks

Does a benzene ring react like three independent double bonds? — Tempting mistake: “Benzene should readily add bromine like an alkene.”

1 worked visual example · 8 “If your child says…” checks

Can you switch an element and a subset? — Tempting mistake: “1 is a subset of {1, 2}.”

1 worked visual example · 8 “If your child says…” checks

Can a function send one input to two outputs? — Tempting mistake: “The relation {(1, 2), (1, 3)} is a function.”

1 worked visual example · 8 “If your child says…” checks

Does a sine value identify just one angle? — Tempting mistake: “If sin θ = ½, θ must be 30°.”

1 worked visual example · 8 “If your child says…” checks

Does a negative discriminant mean a quadratic has no solutions at all? — Tempting mistake: “x² + 1 = 0 has no solutions because a square cannot be negative.”

1 worked visual example · 8 “If your child says…” checks

Can you multiply an inequality by a negative without reversing it? — Tempting mistake: “From −2x < 6, divide by −2 to get x < −3.”

1 worked visual example · 8 “If your child says…” checks

When does order count? — Tempting mistake: “Choosing A then B is always different from choosing B then A.”

1 worked visual example · 8 “If your child says…” checks

Can you raise each part of a sum to a power separately? — Tempting mistake: “(x + 1)³ = x³ + 1”

1 worked visual example · 8 “If your child says…” checks

Is a term the same as the sum up to it? — Tempting mistake: “For 2, 4, 8, the third partial sum is 8.”

1 worked visual example · 8 “If your child says…” checks

Is the slope of a vertical line zero? — Tempting mistake: “A vertical line has slope 0 because there is no horizontal change.”

1 worked visual example · 8 “If your child says…” checks

Does the denominator determine a parabola’s axis? — Tempting mistake: “In y² = 8x, the axis is vertical because y is squared.”

1 worked visual example · 8 “If your child says…” checks

Is the xy-plane where x and y are zero? — Tempting mistake: “The xy-plane is defined by x = y = 0.”

1 worked visual example · 8 “If your child says…” checks

Must a limit equal the function value? — Tempting mistake: “If f(2) is undefined, the limit as x tends to 2 cannot exist.”

1 worked visual example · 8 “If your child says…” checks

Does equal mean imply equal spread? — Tempting mistake: “Two sets with mean 5 must have the same spread.”

1 worked visual example · 8 “If your child says…” checks

Do mutually exclusive events count as independent? — Tempting mistake: “Two outcomes that cannot happen together must be independent.”

1 worked visual example · 8 “If your child says…” checks

Do more decimal places guarantee accuracy? — Tempting mistake: “A reading of 10.50 cm must be accurate because it includes hundredths.”

1 worked visual example · 8 “If your child says…” checks

Does negative acceleration always mean slowing down? — Tempting mistake: “A car with acceleration −2 m/s² is slowing down.”

1 worked visual example · 8 “If your child says…” checks

Does a projectile have upward acceleration while rising? — Tempting mistake: “An upward-moving projectile accelerates upward.”

1 worked visual example · 8 “If your child says…” checks

Do action and reaction cancel on one object? — Tempting mistake: “Equal action and reaction forces cancel, so nothing accelerates.”

1 worked visual example · 8 “If your child says…” checks

Does effort always mean positive work on an object? — Tempting mistake: “The brake force does positive work because it acts on the moving car.”

1 worked visual example · 8 “If your child says…” checks

Does force alone decide how easily a door turns? — Tempting mistake: “The same push turns the door equally well anywhere.”

1 worked visual example · 8 “If your child says…” checks

Is an astronaut weightless because gravity is absent? — Tempting mistake: “Astronauts float because gravity has stopped acting.”

1 worked visual example · 8 “If your child says…” checks

Does elastic mean easy to stretch? — Tempting mistake: “Rubber has a larger Young’s modulus than steel because it stretches easily.”

1 worked visual example · 8 “If your child says…” checks

Does liquid pressure depend on container shape? — Tempting mistake: “The wide tank has greater water pressure at the same depth.”

1 worked visual example · 8 “If your child says…” checks

Can a temperature rise be used as the only measure of energy added? — Tempting mistake: “If ice stays at 0 °C while melting, it absorbs no energy.”

1 worked visual example · 8 “If your child says…” checks

Does zero heat transfer mean constant temperature? — Tempting mistake: “An insulated gas stays at the same temperature when compressed.”

1 worked visual example · 8 “If your child says…” checks

Does equal temperature mean equal molecular speed? — Tempting mistake: “Helium and oxygen molecules have the same average speed at the same temperature.”

1 worked visual example · 8 “If your child says…” checks

Where does a spring mass move fastest? — Tempting mistake: “The mass moves fastest at maximum stretch because the spring pulls hardest there.”

1 worked visual example · 8 “If your child says…” checks

Do particles travel along a wave? — Tempting mistake: “A pulse carries the particles of a string to the far end.”

1 worked visual example · 8 “If your child says…” checks