25 questions in 25 minutes on the NTA computer-based test interface, all from Cell: The Unit of Life. +4 / -1 marking, instant score, full solutions. Free, no login.
A chapter test is the fastest honest check on whether a chapter has actually landed. This one draws 25 questions from Cell: The Unit of Life, of which 18 are real NEET previous-year questions and 0 sit at the harder end of the bank. Sit it in one 25-minute block, the way you would in the hall.
Revising first? Read the Cell: The Unit of Life chapter notes, then come back and take this test to check it stuck.
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Duration: 180 minutes · 180 questions · 720 marks maximum
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NEET CBT mock test: common questions
How many questions are in this Cell: The Unit of Life mock test?
25 questions in 25 minutes, marked +4 for a correct answer and -1 for a wrong one, exactly like the real paper. 18 of them are NEET previous-year questions.
Is this the same interface as the real NEET CBT?
Yes. On-screen countdown, colour-coded question palette, Save & Next, Clear Response and Mark for Review, then an instant score with full solutions.
Should I take this before or after revising Cell: The Unit of Life?
Both, and that is the point. Take it cold to find out what you actually do not know, revise from the chapter notes, then retake it to confirm the gap closed.
All 25 questions with answers and solutions
The complete paper in text form, with the correct option and a worked explanation for every question. Sit the timed test above first: the score is only worth having if you earn it. Then open this to revise, or to re-read a question you got wrong without replaying the whole paper.
Show all 25 questions with answers and solutions
Botany
- Q1The mesosome in a prokaryotic cell is formed by the infolding of which structure?
- Glycocalyx
- Plasma membrane
- Cell wall
- Nuclear membrane
Answer: (B) Plasma membrane
A mesosome is an extension of the plasma membrane into the cytoplasm. It helps in respiration, secretion, DNA replication and cell wall formation. Prokaryotes have no nuclear membrane.
- Q2The organelles included in the endomembrane system are:
- endoplasmic reticulum, Golgi complex, lysosomes and vacuoles
- endoplasmic reticulum, mitochondria, ribosomes and lysosomes
- Golgi complex, mitochondria, ribosomes and lysosomes
- Golgi complex, endoplasmic reticulum, mitochondria and lysosomes
Answer: (A) endoplasmic reticulum, Golgi complex, lysosomes and vacuoles
The endomembrane system is the group of membranes whose functions are coordinated: endoplasmic reticulum, Golgi complex, lysosomes and vacuoles. Mitochondria, chloroplasts, peroxisomes and (non-membranous) ribosomes are excluded.
- Q3Extra-nuclear inheritance is a consequence of the presence of genes in:
- endoplasmic reticulum and mitochondria
- ribosomes and chloroplasts
- mitochondria and chloroplasts
- lysosomes and ribosomes
Answer: (C) mitochondria and chloroplasts
Extra-nuclear (cytoplasmic/organellar) inheritance arises because mitochondria and chloroplasts carry their own DNA, which functions independently of the nuclear genome. The ER, ribosomes and lysosomes have no genome.
- Q4Some enzymes that convert fats into carbohydrates are present in:
- glyoxysomes
- liposomes
- Golgi bodies
- microsomes
Answer: (A) glyoxysomes
Glyoxysomes contain the enzymes of the glyoxylate cycle, through which fats are converted into carbohydrates (gluconeogenesis from lipids) in germinating fatty seeds. (Catalase and beta-oxidation enzymes also occur there.)
- Q5The prokaryotic flagellum possesses:
- a unit-membrane-enclosed fibre
- a ‘9+2’ membrane-enclosed structure
- a protein-membrane-enclosed fibre
- a helically arranged protein molecule (flagellin)
Answer: (D) a helically arranged protein molecule (flagellin)
The bacterial flagellum is made of the protein flagellin arranged helically and is NOT membrane-enclosed; it lacks the 9+2 axoneme of eukaryotic flagella. It rotates like a propeller driven by the basal body rather than beating, so D is correct.
- Q6The bacterial ribosome (70S) is made up of which two subunits?
- 60S and 30S
- 50S and 30S
- 60S and 40S
- 40S and 30S
Answer: (B) 50S and 30S
The 70S prokaryotic ribosome consists of a larger 50S subunit and a smaller 30S subunit. Note that S (Svedberg units) reflect sedimentation, so they do not add up arithmetically. The 80S eukaryotic ribosome has 60S + 40S.
- Q7Genes located on mitochondrial DNA:
- are always inherited from the male parent
- are not inherited
- generally show maternal inheritance
- show biparental inheritance like the nuclear genes
Answer: (C) generally show maternal inheritance
Mitochondria are transmitted through the egg cytoplasm (the female parent), so mitochondrial DNA generally shows maternal (cytoplasmic) inheritance. They are not inherited from the male parent nor biparentally as a rule.
- Q8Experiments on Acetabularia by Hammerling proved the role of:
- nucleocytoplasmic ratio
- chromosomes in heredity
- cytoplasm in controlling differentiation
- nucleus in heredity
Answer: (D) nucleus in heredity
Hammerling’s grafting experiments on the alga Acetabularia (exchanging the rhizoid/nucleus-bearing base) showed that the cap that regenerated matched the species of the nucleus, proving the nucleus controls heredity and morphology.
- Q9What will be the direction of flow of water when a plant cell is placed in a hypotonic solution?
- Water will flow into the cell
- Water will flow in both directions equally
- Water will flow out of the cell
- No flow of water in any direction
Answer: (A) Water will flow into the cell
A hypotonic solution has a higher water potential (more dilute) than the cell sap. Water therefore moves down its water-potential gradient, i.e. from the surrounding solution INTO the cell by endosmosis, making the cell turgid. It does not flow out (that happens in a hypertonic solution) nor stop (that is an isotonic solution).
- Q10Which of the following cell organelles is responsible for extracting energy from carbohydrates to form ATP?
- Chloroplast
- Lysosome
- Mitochondrion
- Ribosome
Answer: (C) Mitochondrion
The mitochondrion (power house of the cell) oxidises carbohydrates by aerobic respiration to produce ATP. Chloroplasts make food but do not extract energy from carbohydrates; lysosomes digest and ribosomes synthesise protein.
- Q11The movement of water across a selectively permeable membrane is best described as:
- Osmosis, a passive process
- Active transport using ATP
- Endocytosis
- Facilitated transport against the gradient
Answer: (A) Osmosis, a passive process
Water moves passively across a membrane from higher to lower water potential by osmosis, requiring no ATP. Active transport moves solutes against the gradient using energy.
- Q12Select the WRONG statement about prokaryotes.
- Pili and fimbriae are mainly involved in motility of bacterial cells
- Cyanobacteria lack flagellated cells
- Mycoplasma is a wall-less microorganism
- Bacterial cell wall is made up of peptidoglycan
Answer: (A) Pili and fimbriae are mainly involved in motility of bacterial cells
Pili and fimbriae are short surface hair-like appendages used for ATTACHMENT and (for sex pili) conjugation, NOT for motility; motility is by flagella. The other three statements are correct, so B is the wrong statement.
- Q13The main difference between Gram-positive and Gram-negative bacteria lies in their:
- cytoplasm
- flagella
- cell wall
- cell membrane
Answer: (C) cell wall
Gram staining differentiates bacteria on the basis of the composition and thickness of the cell WALL (peptidoglycan content). Gram-positive walls are thick and retain the crystal-violet stain; Gram-negative walls are thin and lipid-rich and lose it.
- Q14Microtubule is involved in:
- muscle contraction
- DNA recognition
- membrane architecture
- cell division
Answer: (D) cell division
Microtubules form the spindle apparatus that segregates chromosomes during cell division, and they guide organelle and chromosome movement. Membrane architecture, muscle contraction and DNA recognition involve other molecules.
- Q15The rough endoplasmic reticulum (RER) is mainly involved in:
- Protein synthesis and secretion
- ATP production
- Lipid and steroid synthesis
- Photosynthesis
Answer: (A) Protein synthesis and secretion
RER bears ribosomes on its surface and is extensive in cells actively making proteins for secretion. SER lacks ribosomes and synthesises lipids and steroids.
- Q16Which one of the following has its own DNA?
- Mitochondria
- Peroxisome
- Lysosome
- Dictyosome
Answer: (A) Mitochondria
Mitochondria possess their own circular DNA and 70S ribosomes, making them semi-autonomous. Dictyosomes (Golgi), lysosomes and peroxisomes do not have their own DNA.
- Q17Which one of the following structures between two adjacent cells is an effective transport pathway?
- Plasmalemma
- Endoplasmic reticulum
- Plasmodesmata
- Plastoquinones
Answer: (C) Plasmodesmata
Plasmodesmata are cytoplasmic bridges passing through the cell wall via primary pit fields; they connect the cytoplasm of adjacent cells and permit symplastic translocation of fluid and solutes, making them the effective transport pathway.
- Q18Inclusion bodies of blue-green, purple and green photosynthetic bacteria are:
- contractile vacuoles
- microtubules
- centrioles
- gas vacuoles
Answer: (D) gas vacuoles
Gas vacuoles are inclusion bodies in many aquatic prokaryotes (blue-green, purple and green photosynthetic bacteria). They are small hollow cylindrical structures (gas vesicles) that aid buoyancy and are permeable to gases.
- Q19Which among the following is NOT a prokaryote?
- Mycobacterium
- Saccharomyces
- Oscillatoria
- Nostoc
Answer: (B) Saccharomyces
Saccharomyces (yeast) is a fungus and therefore a eukaryote with a true membrane-bound nucleus and organelles. Nostoc and Oscillatoria are cyanobacteria and Mycobacterium is a true bacterium, all of which are prokaryotes lacking a defined nucleus.
- Q20The Fluid Mosaic Model of the plasma membrane was proposed by:
- Schleiden and Schwann
- Singer and Nicolson
- Camillo Golgi
- Robertson
Answer: (B) Singer and Nicolson
Singer and Nicolson (1972) proposed the fluid mosaic model, in which proteins float in or on a fluid lipid bilayer, allowing lateral movement. Robertson proposed the earlier unit membrane model.
- Q21The middle lamella that holds adjacent plant cells together is mainly composed of:
- Cellulose
- Lignin
- Hemicellulose
- Calcium pectate
Answer: (D) Calcium pectate
The middle lamella is mainly calcium pectate and acts as a cement between the walls of neighbouring plant cells. Cellulose, hemicellulose and pectin make up the wall layers themselves.
- Q22In plant cells, peroxisomes are associated with:
- photorespiration
- photoperiodism
- photosynthesis
- phototropism
Answer: (A) photorespiration
Peroxisomes are microbodies that, in green mesophyll cells of C3 plants, participate in photorespiration by interacting with chloroplasts and mitochondria. They are not involved in tropic or photoperiodic responses.
- Q23Resolution power is the ability to:
- magnify the image
- distinguish two close objects as separate
- distinguish amongst organelles by colour
- distinguish two distant trees
Answer: (B) distinguish two close objects as separate
Resolving power is the ability of an optical system to distinguish two points that lie very close together as two separate points. It is NOT magnification (mere enlargement of image size), so B is correct.
- Q24A major site for the synthesis of lipids in the cell is the:
- SER
- nucleoplasm
- symplast
- RER
Answer: (A) SER
The smooth endoplasmic reticulum (SER), which lacks ribosomes, is the major site of lipid and steroid synthesis. The RER (with ribosomes) makes proteins.
- Q25Assertion (A): Cytoplasm of adjacent plant cells remains connected. Reason (R): Plasmodesmata are cytoplasmic bridges that pass through the cell walls.
- A is true but R is false
- Both A and R are true but R is not the correct explanation of A
- Both A and R are true and R is the correct explanation of A
- A is false but R is true
Answer: (C) Both A and R are true and R is the correct explanation of A
Plasmodesmata are channels through the cell walls linking the cytoplasm (symplast) of adjacent cells, enabling cell-to-cell communication and transport. So R correctly explains A.