Which one of the following statements about lysosomes is NOT correct?
- (a)They are waste disposal system of the cell
- (b)They breakdown all inorganic materials
- (c)These are also referred to as "suicidal bags"
- (d)Lysosomes stop entry of foreign materials
Correct — B, 'They breakdown all inorganic materials'. This is the FALSE statement (and the question asks which is NOT correct). Lysosomes are membrane-bound sacs packed with acid hydrolase enzymes that digest ORGANIC/biological matter — worn-out organelles, proteins, lipids, carbohydrates and nucleic acids — during intracellular digestion. They do not break down 'inorganic materials', let alone 'all' of them, so option (b) is untrue.
- (a)They are waste disposal system of the cell — This is a CORRECT statement, so it is not the answer. Lysosomes clear cellular debris and digest worn-out or damaged organelles (autophagy), earning them the tag 'cell's waste-disposal / clean-up system'.
- (c)These are also referred to as "suicidal bags" — This is a CORRECT statement. When a cell is injured or ageing, its lysosomes may burst and their enzymes digest the cell's own contents (autolysis) — which is why lysosomes are nicknamed 'suicidal bags' (a coinage of Christian de Duve, who discovered them).
- (d)Lysosomes stop entry of foreign materials — Treated as a CORRECT/acceptable statement here: lysosomes fuse with phagosomes and digest foreign particles (bacteria, viruses) that enter the cell, acting as a defensive clean-up mechanism. The wording is loose, but option (b) is the clear-cut false statement, so (d) is not the intended answer.
Lysosomes are single-membrane organelles found mainly in animal cells. They are formed by the Golgi apparatus and filled with about 40 acidic digestive enzymes (acid hydrolases) that work best around pH 5. Their job is intracellular digestion: breaking down old organelles, macromolecules and engulfed foreign matter into reusable building blocks.
A 'NOT correct' question rewards you for spotting the one over-stated claim. Three options describe real lysosome roles (waste disposal, self-digestion 'suicidal bags', digesting foreign material). Only (b) contains a factual error — swapping 'organic/biological' for 'inorganic', plus the give-away absolute word 'all'. Sweeping words like 'all' are a classic trap flag.
- Lysosomes contain acid hydrolase enzymes that digest organic macromolecules (proteins, lipids, carbohydrates, nucleic acids).
- They are called 'suicidal bags' because their enzymes can digest the cell itself (autolysis) on injury or death.
- Discovered by Christian de Duve (Nobel Prize 1974); they bud off from the Golgi apparatus.
- They are the cell's 'waste-disposal system', clearing worn-out organelles by autophagy and foreign matter by heterophagy.
Only the 'inorganic materials' claim is false — hence the NOT-correct statement is (b).
- Absolute words like 'all' / 'always' usually flag the false option in a NOT-correct question.
- Confusing lysosomes (digestion) with ribosomes (protein synthesis) or mitochondria (energy).
Cell organelles are asked as 'which function belongs to which organelle' or as 'which statement is NOT correct' — learn each organelle's one-line role.
No directly related past PYQ was found.
- practice — not a real PYQ
Lysosomes are called 'suicidal bags' of the cell because they
- (a)store genetic material
- (b)can digest the cell's own contents on damage
- (c)carry out photosynthesis
- (d)synthesise proteins
Answer(b) can digest the cell's own contents on damage — their enzymes cause autolysis, hence 'suicidal bags'.
- practice — not a real PYQ
Lysosomal digestive enzymes are best described as
- (a)acid hydrolases
- (b)oxidases
- (c)polymerases
- (d)ligases
Answer(a) acid hydrolases — they work in the acidic (pH ~5) interior of the lysosome.