Q.How many shoot apical meristems are likely to be present in a twig of a plant possessing 4 branches and 26 leaves?
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🔒 Start your 14-day free trial to unlock the full solution →Concept understanding — Cell Organelle Matching
Learning cell biology can feel like walking into a busy workshop where every tool has a job — and the skill you are really building is matching each organelle to the task it performs. Once you can pair a structure with its function on sight, the whole cell stops being a jumble of names and starts making sense as an organised, cooperating team.
Here is a practical set of pairings that come up again and again:
- Nucleus — control and heredity. It directs the activities of the other organelles and holds the chromatin (DNA), the cell's hereditary information.
- Mitochondria — energy. Aerobic respiration happens here, generating ATP, which is why they are called the power houses of the cell.
- Chloroplast — capturing light. Found in plant cells, it holds chlorophyll and traps light energy for photosynthesis.
- Ribosome — protein synthesis. The site where proteins are assembled; it has no membrane and can sit free in the cytoplasm or on the rough ER.
- Rough endoplasmic reticulum — protein-making highway. ER studded with ribosomes; abundant in cells that actively make and export proteins.
- Smooth endoplasmic reticulum — lipid factory. The main site for making lipids, and in animal cells, steroid hormones.
- Golgi apparatus — packaging and dispatch. It modifies, packages and sends materials to targets inside or outside the cell.
- Lysosome — the cell's stomach. Filled with hydrolytic enzymes that digest carbohydrates, proteins, lipids and nucleic acids.
- Vacuole — storage. A membrane-bound pocket (bounded by the tonoplast) that stores water, sap and waste; very large in plant cells.
- Cell wall — rigid support. A non-living outer layer in plants and fungi that gives shape and protection. …
A shoot apical meristem sits at the very tip of each growing shoot axis — the main axis and every branch — and it is what allows that particular axis to keep elongating. Leaves, in contrast, do not carry their own apical meristem; they are produced laterally by the shoot apical meristem and simply grow to a fixed size. …
Leaves do not have their own apical meristem — only growing axes do — so a main shoot plus 4 branches gives 1 + 4 = 5 shoot apical meristems, independent of the leaf count.
A shoot apical meristem is the actively dividing tissue located at the extreme tip of a stem axis; it is responsible for the primary growth (lengthening) of that particular axis and for laying down new leaf primordia and lateral buds along the way.
- Leaves are lateral outgrowths produced BY a shoot apical meristem — they are not themselves growing axes and do not carry a meristem of their own once formed, so the number of leaves (26 here) has no bearing on the count of meristems. …
Method: Drawing the Branching Tree and Counting Only the Growing Tips
Rather than reasoning about leaves and branches in the abstract, sketch a simple branching-tree diagram of the twig and count only the tips that are actively growing axes — this makes the leaf-count distractor visually obvious to ignore.
Draw it: put a single vertical line for the main shoot axis, and let 4 side-branches emerge from it at various points along its length. Along the main axis and the branches, scatter 26 small leaf-shaped marks wherever convenient — the exact positions don't matter for this count.
Now look only at the LINE ENDS (the tips of the drawn axes), not the leaf marks. Each drawn axis — the main stem plus each of the 4 branches — has exactly one tip, and it is only at a tip that a shoot apical meristem can sit (a meristem is a growing point, and growing points exist only where an axis is still elongating). The leaf marks you scattered are attached partway ALONG an axis, not at a tip of their own, which is a direct visual reminder that leaves do not carry independent apical meristems. …
- AP EAPCET 2026Set ap-2026-05-19-FN1 markMCQQ.Match the following lists List-I | List-II I. Main arena of cellular activity of a cell | A. Passive transport II. Cells arise from pre-existing cells | B. Mesosome III. Extention of plasmamembrane | C. Cytoplasm IV. Movement of molecules across the membrane without energy utilization | D. Virchow (A) I-C, II-D, III-B, IV-A (B) I-C, II-B, III-D, IV-A (C) I-C, II-A, III-B, IV-D (D) I-C, II-D, III-A, IV-B
›Reveal solutionSolution
Matches four cell-biology facts to their terms: cytoplasm (main arena of activity), Virchow (cells from pre-existing cells), mesosome (plasma-membrane extension), and passive transport (energy-free movement across the membrane).
Concept and Intuition
This is a straightforward vocabulary-matching exercise from the introductory "Cell" chapter, pairing structures/scientists/processes with their defining description.
Step-by-Step Solution
- I: The cytoplasm, the semi-fluid matrix between the plasma membrane and the nucleus, hosts the majority of a cell's metabolic reactions — hence "the main arena of cellular activity." Match: C.
- II: Rudolf Virchow proposed that all cells arise from pre-existing cells (extending Schleiden and Schwann's cell theory). Match: D.
- III: Mesosomes are folded extensions/invaginations of the bacterial plasma membrane, increasing surface area for respiratory enzymes, DNA replication anchoring, etc. Match: B. …
- AP EAPCET 2026Set ap-2026-05-19-AN1 markMCQQ.Match the following I: A - Fat soluble carotenoids; B - Smooth Endoplasmic reticulum; C - Tonoplast facilitates transport; D - Nuclear pores are passages for II: I - Steroidal hormones synthesis; II - Chromoplasts; III - RNA and protein molecules; IV - Against concentration gradient (A) A-II, B-III, C-I, D-IV (B) A-I, B-II, C-III, D-IV (C) A-III, B-I, C-IV, D-II (D) A-II, B-I, C-IV, D-III
›Reveal solutionSolution
Each organelle/structure clue links to its correct cellular role: chromoplasts hold carotenoids, SER makes steroids, tonoplast pumps against a gradient, and nuclear pores pass RNA/protein — giving A-II, B-I, C-IV, D-III.
Concept and Intuition
Each cell organelle in 'Cell: The Unit of Life' has a signature biochemical role worth memorising as a pair: chromoplasts = fat-soluble pigments (carotenoids), smooth ER = lipid/steroid hormone synthesis, tonoplast = active (against-gradient) solute transport into the vacuole, nuclear pore complex = selective passage of RNA and proteins between nucleus and cytoplasm.
Step-by-Step Solution
- A (fat-soluble carotenoids) is the defining pigment class of chromoplasts → A-II.
- B (smooth ER) is well known as the organelle synthesising steroidal hormones and lipids → B-I.
- C (tonoplast facilitates transport) actively pumps ions/solutes into the vacuole against their concentration gradient, maintaining turgor → C-IV. …
- AP EAPCET 2026Set ap-2026-05-20-FN1 markMCQQ.Identify the non-membrane bound bodies in the cell among the following A) Chloroplast B) Peroxysomes C) Ribosome D) Endoplasmic reticulum E) Phosphate granules F) glycogen granules (A) A, B (B) C, D (C) E, F (D) A, D
›Reveal solutionSolution
Among the listed cell structures, phosphate granules and glycogen granules are non-membrane-bound inclusion bodies, unlike the membrane-bound chloroplast, peroxisome, and endoplasmic reticulum.
Concept and Intuition
Cell organelles are broadly divided into membrane-bound (chloroplast, mitochondria, ER, Golgi, peroxisomes, lysosomes — each enclosed by one or two membranes) and non-membrane-bound structures (ribosomes and various cytoplasmic inclusion bodies such as phosphate granules, cyanophycean granules, and glycogen granules, which are simply masses of stored material without any surrounding membrane).
Step-by-Step Solution
- Chloroplast (A): membrane-bound (double membrane, an organelle).
- Peroxisomes (B): membrane-bound (single membrane microbody).
- Ribosome (C): non-membrane bound, but not offered paired with E or F in the answer choices.
- Endoplasmic reticulum (D): membrane-bound (extensive single-membrane network). …
- AP EAPCET 2024Set ap-2024-05-16-AN1 markMCQQ.Match the following List A: I Glyoxysome, II Plastids, III Nucleolus, IV Mitochondria List B: A Synthesis of ATP, B convert lipids to carbohydrates, C Synthesis of carbohydrates & proteins, D Ribosomal RNA synthesis, E Synthesis of Nucleases (A) I-B II-E III-C IV-D (B) I-A II-E III-D IV-B (C) I-B II-E III-D IV-A (D) I-B II-C III-D IV-A
›Reveal solutionSolution
This tests recall of organelle-function pairing: glyoxysome (lipid to carbohydrate), plastid (carbohydrate/protein synthesis), nucleolus (rRNA synthesis), mitochondrion (ATP synthesis).
Concept and Intuition
Each organelle has a signature biochemical role rooted in its structure. Glyoxysomes are specialized peroxisome-like bodies found in germinating oily seeds; they house the glyoxylate cycle, which converts the acetyl-CoA from fatty-acid breakdown into succinate, ultimately feeding gluconeogenesis to build carbohydrates for the growing seedling. Plastids are semi-autonomous, carrying their own circular DNA and 70S ribosomes, so besides making carbohydrates via photosynthesis, they can synthesize some of their own proteins. The nucleolus is a dense nuclear region dedicated to transcribing rRNA genes and assembling ribosomal subunits. Mitochondria house the electron transport chain and ATP synthase, making them the principal ATP-generating organelle.
Step-by-Step Solution
- Glyoxysome converts lipids to carbohydrates (glyoxylate cycle) -> B. …
- AP EAPCET 2024Set ap-2024-05-16-FN1 markMCQQ.Identify the cell organelles present in animals and absent in plant cells, present in plant cells and absent in animals, present in only prokaryotes (A) Centriole, Cytoskeleton, Inclusion bodies (B) Axoneme, Flagellum, Mesosomes (C) Ribosomes, Plasma membrane, Flagellum (D) Fimbriae, Flagellum, Mesosomes
›Reveal solutionSolution
Matches organelles to their exclusive occurrence: centrioles (animal cells, absent in most plants), a plant-associated structure (cytoskeleton, as given in this option set), and inclusion bodies (prokaryotes only).
Concept and Intuition
Certain cell structures are classic markers distinguishing animal cells, plant cells, and prokaryotic cells from one another — testing whether a structure is universal (present in all cells) or restricted to one cell type helps eliminate wrong option combinations.
Step-by-Step Solution
- Present in animals, absent in plants: Centrioles are a hallmark animal-cell structure (organizing the mitotic spindle and forming basal bodies of cilia/flagella); higher plant cells lack them. This rules in "Centriole" as the correct first item.
- Present in only prokaryotes: Inclusion bodies (storage granules for reserve food material, e.g., glycogen, lipid, or gas vacuoles) are characteristic of prokaryotic (bacterial) cells. This rules in "Inclusion bodies" as the correct third item. …
- AP EAPCET 2023Set ap-2023-05-23-AN1 markMCQQ.Name the cell organelle which are involved in the following processes A. Conversion of stored lipids to carbohydrates B. Catabolism of long chain fatty acids (A) Lysosome, Peroxysome (B) Dictyosome, Ribosome (C) Peroxisome, Micro bodies (D) Glyoxysome, Peroxysome
›Reveal solutionSolution
This tests knowledge of two specialised microbodies — glyoxysomes (lipid-to-carbohydrate conversion) and peroxisomes (fatty acid catabolism).
Concept and Intuition
Microbodies are small membrane-bound organelles specialised for particular metabolic pathways. Glyoxysomes, found especially in the fat-storing tissues of germinating oily seeds, house the enzymes of the glyoxylate cycle, which allows stored triglycerides to be converted into sugars needed for seedling growth before photosynthesis begins. Peroxisomes contain enzymes (including catalase) that carry out oxidative reactions, including the catabolism (breakdown) of long-chain fatty acids via beta-oxidation, generating hydrogen peroxide as a by-product that catalase then detoxifies.
Step-by-Step Solution
- Process A — "Conversion of stored lipids to carbohydrates" — is the hallmark function of the glyoxysome (via the glyoxylate cycle).
- Process B — "Catabolism of long chain fatty acids" — is carried out by the peroxisome. …
- AP EAPCET 2022Set ap-2022-07-11-FN1 markMCQQ.Choose the correct one A B C I. Golgibodies Single membraned Protein synthesis II. Mitochondrion Power house of the cell DNA Replication III. Chloroplast Carbohydrate synthesis Protein synthesis IV. Nucleolus Ribosomal factory 80s and 70s ribosomes synthesis (A) I, II, III, IV (B) II, III (C) II, III, IV (D) II only
›Reveal solutionSolution
Only the mitochondrion and chloroplast rows correctly pair organelle, primary function, and additional (semi-autonomous) feature; the Golgi and nucleolus rows each contain one incorrect claim.
Concept and Intuition
Mitochondria and chloroplasts are unique among organelles in being semi-autonomous — each carries its own circular DNA and 70S ribosomes, letting it replicate its genome and translate a subset of its own proteins independently of the nucleus, in addition to their main metabolic roles (respiration/ATP synthesis; photosynthesis/carbohydrate synthesis). The Golgi apparatus and nucleolus, by contrast, do NOT synthesise proteins themselves.
Step-by-Step Solution
- Row I (Golgi bodies): single-membrane bound is correct, but Golgi does packaging/glycosylation/secretion of proteins made elsewhere (rough ER) — it does not itself synthesise protein. Row fails on column C.
- Row II (Mitochondrion): "power house of the cell" (true, via oxidative phosphorylation) and mtDNA replication (true, since mitochondria are semi-autonomous). Row fully correct. …
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