Microbodies found to be present in plant and animal cells contain
- (a)broken down membranes
- (b)enzymes
- (c)acidic fluids
- (d)waste metabolites
Correct — B, enzymes. The stem is lifted almost word for word from NCERT, which closes its tour of the cell with the line: 'Many membrane bound minute vesicles called microbodies that contain various enzymes, are present in both plant and animal cells.' That is the whole answer. A microbody is a small vesicle, roughly 0.2 to 1.5 micrometres across, wrapped in a single phospholipid bilayer and filled with a protein matrix whose working content is enzymes. The family includes peroxisomes, which carry oxidases and catalase, and the glyoxysomes of plant cells, which add the enzymes of the glyoxylate cycle. Unlike mitochondria and chloroplasts, microbodies carry no genetic material of their own.
- (a)broken down membranes — A microbody is defined by its own intact single membrane and its enzyme-rich matrix; scraps of dismantled membrane are debris, not the contents of an organelle.
- (c)acidic fluids — The acidic interior belongs to the lysosome, which keeps its hydrolytic enzymes working at a low pH. That is a different organelle from the microbody, and NCERT lists the two separately.
- (d)waste metabolites — Storing waste products and metabolites in cell sap is the job of the large central vacuole in a plant cell, not of a microbody.
The eukaryotic cell is defined by its membrane-bound organelles — the endoplasmic reticulum, Golgi complex, lysosomes, mitochondria, microbodies and vacuoles — none of which a prokaryotic cell possesses. Microbodies are the smallest of these. Each is a spherical vesicle bounded by a single membrane and packed with enzymes for specialised oxidative work. Peroxisomes handle reactions that generate hydrogen peroxide and then destroy it with catalase; glyoxysomes, found in plants, run the glyoxylate cycle that lets a germinating oilseed convert stored fat into sugar.
This is a definition-recall item, and the fastest way to it is to sort the options by which organelle each one actually describes. An acidic interior points to the lysosome, stored waste metabolites point to the vacuole, and broken membranes describe nothing at all — leaving enzymes as the only content that belongs to a microbody. It is fair to object that lysosomes are also full of enzymes, so 'contains enzymes' does not uniquely identify a microbody in the abstract; but the stem asks what microbodies contain, not what only they contain, and NCERT's sentence answers it directly. One useful discriminator to carry forward: microbodies and lysosomes both have a single membrane and no DNA, while mitochondria and chloroplasts have a double membrane and their own DNA and ribosomes.
- NCERT: 'Many membrane bound minute vesicles called microbodies that contain various enzymes, are present in both plant and animal cells.'
- A microbody is a vesicle about 0.2 to 1.5 micrometres across with a single phospholipid bilayer membrane and a matrix of enzymes and other proteins.
- Peroxisomes, glyoxysomes, glycosomes and hydrogenosomes are all counted as microbodies; peroxisomes carry oxidases and catalase.
- Microbodies contain no genetic material of their own, unlike mitochondria and chloroplasts.
- Ribosomes, by contrast, are non-membrane-bound organelles and occur in prokaryotic as well as eukaryotic cells.
Sorting the option list by organelle leaves enzymes as the only content that belongs to a microbody.
- Choosing 'acidic fluids' by confusing the microbody with the lysosome; both hold enzymes, only one is acidic.
- Assuming microbodies are plant-only or animal-only structures — NCERT stresses that they occur in both.
- Crediting microbodies with their own DNA the way mitochondria and chloroplasts have it.
Asked as a direct definition item, and in sibling papers as an organelle-to-function matching set.
Match List I (Physiological processes) with List II (Cell organelles) and select the correct answer by using the codes given below the lists: List I — I. Photosynthesis, II. Mineral uptake, III. Respiration, IV. Protein Synthesis. List II — A) Plasma membrane, B) Chloroplast, C) Mitochondria, D) Ribosomes.
- (a) I-A, II-B, III-C, IV-D
- (b) I-A, II-B, III-D, IV-C
- (c) I-B, II-A, III-C, IV-D
- (d) I-B, II-A, III-D, IV-C
Answer(c) I-B, II-A, III-C, IV-D
The same skill on a wider list — attaching each organelle to what it actually does. Get that mapping firm and the microbody item answers itself, because every wrong option here is another organelle's job description.
CDS_GK_2023_II_Q442023Which one of the following is the correct combination of organelles and their functions?
- (a) Mitochondria – Respiration; Chloroplast – Photosynthesis; Ribosome – Protein Synthesis; Rough endoplasmic reticulum – Transport of proteins
- (b) Mitochondria – Respiration; Chloroplast – Photosynthesis; Ribosome – Transport of proteins; Rough endoplasmic reticulum – Protein synthesis
- (c) Mitochondria – Respiration; Chloroplast – Protein synthesis; Ribosome – Photosynthesis; Rough endoplasmic reticulum – Transport of proteins
- (d) Mitochondria – Photosynthesis; Chloroplast – Respiration; Ribosome – Protein synthesis; Rough endoplasmic reticulum – Transport of proteins
Answer(a) Mitochondria – Respiration; Chloroplast – Photosynthesis; Ribosome – Protein Synthesis; Rough endoplasmic reticulum – Transport of proteins
CDS asks this pairing repeatedly. That item runs the organelle-to-function table across four organelles; this one takes the smallest member of the same table and asks only what it holds.
- practice — not a real PYQ
Which one of the following organelles is bounded by a single membrane and contains no DNA of its own?
- (a)Mitochondrion
- (b)Chloroplast
- (c)Peroxisome
- (d)Nucleus
Answer(c) Peroxisome — a microbody with a single membrane and no genetic material, unlike mitochondria and chloroplasts.
- practice — not a real PYQ
The enzyme catalase, which breaks down hydrogen peroxide, is characteristically found in
- (a)lysosomes
- (b)peroxisomes
- (c)ribosomes
- (d)the Golgi complex
Answer(b) peroxisomes — the microbody whose oxidase reactions generate hydrogen peroxide that catalase then destroys.