15 extra multiple-choice questions for Plant Anatomy and Plant Physiology (10th Standard Science, Samacheer Kalvi), beyond the ones printed in the textbook — each with the correct option highlighted and a clear, worked explanation. Free to read in English and Tamil.
Q1
Who among the following scientists is recognized as the Father of Plant Anatomy for publishing the first detailed account of internal plant structures?
- A. Sachs
- B. Nehemiah GrewCorrect
- C. Robert Hill
- D. Melvin Calvin
Explanation. Nehemiah Grew is known as the Father of Plant Anatomy. He published the earliest detailed account on the internal cellular structure of plants.
Q2
In which type of vascular bundle are xylem and phloem arranged alternately along different radii?
- A. Conjoint collateral bundle
- B. Bicollateral vascular bundle
- C. Radial vascular bundleCorrect
- D. Concentric vascular bundle
Explanation. In a radial vascular bundle, xylem and phloem patches lie on alternate radii separated by non-vascular tissue, as characteristically seen in roots.
Q3
A vascular bundle in which phloem completely surrounds the centrally located xylem is termed as:
- A. Amphivasal vascular bundle
- B. Amphicribral vascular bundleCorrect
- C. Collateral open bundle
- D. Bicollateral closed bundle
Explanation. In an amphicribral or hadrocentric vascular bundle, xylem occupies the center and is completely surrounded by phloem, as found in ferns.
Q4
What is the arrangement called when protoxylem lies towards the center and metaxylem lies towards the periphery?
- A. Exarch
- B. Polyarch
- C. EndarchCorrect
- D. Tetrarch
Explanation. Endarch xylem condition occurs when the smaller protoxylem vessels develop towards the center and metaxylem towards the outer periphery, which is characteristic of stems.
Q5
The innermost layer of cortex in a dicot root contains band-like suberin thickenings known as:
- A. Bulliform strips
- B. Passage cells
- C. Casparian stripsCorrect
- D. Starch sheath
Explanation. Endodermal cells in roots feature radial and tangential wall thickenings made of suberin called Casparian strips, which regulate water movement into the vascular cylinder.
Q6
Which of the following features distinguishes a dicot root from a monocot root?
- A. Presence of exarch xylem
- B. Radial vascular bundle arrangement
- C. Presence of passage cells in endodermis
- D. Presence of tetrarch xylem bundles and absence of pith at maturityCorrect
Explanation. Dicot roots typically feature tetrarch xylem bundles with absent or inconspicuous pith at maturity, whereas monocot roots display polyarch xylem with a well-developed central pith.
Q7
The hypodermis of a dicot stem provides mechanical strength to the plant body and is composed of:
- A. Sclerenchyma cells
- B. Collenchyma cellsCorrect
- C. Chlorenchyma cells
- D. Parenchyma cells
Explanation. In dicot stems, the hypodermis consists of a few layers of collenchyma cells with thickened corners that offer mechanical support to the growing stem.
Q8
In the transverse section of a monocot stem, what is the characteristic feature observed within the vascular bundle due to disintegration of protoxylem vessels?
- A. Starch sheath
- B. Eustele ring
- C. Protoxylem cavityCorrect
- D. Cambium ring
Explanation. In monocot stems, breakdown of inner protoxylem vessels creates a water-filled lysigenous cavity or protoxylem cavity inside each scattered vascular bundle.
Q9
In a dorsiventral leaf, the mesophyll tissue situated below the upper epidermis consists of elongated cells packed with chloroplasts called:
- A. Spongy parenchyma
- B. Palisade parenchymaCorrect
- C. Bulliform cells
- D. Bundle sheath cells
Explanation. Dicot leaves have mesophyll differentiated into upper palisade parenchyma with columnar, closely packed cells containing abundant chloroplasts for active photosynthesis.
Q10
Which category of plastids is non-pigmented and primarily functions to store food materials in plant cells?
- A. Chloroplasts
- B. Chromoplasts
- C. LeucoplastsCorrect
- D. Phaeoplasts
Explanation. Leucoplasts are colourless, non-pigmented plastids found in non-photosynthetic plant tissues that function in the storage of starch, oils, or proteins.
Q11
The light-dependent reaction of photosynthesis occurs in which specific structural part of the chloroplast?
- A. Stroma
- B. Outer membrane
- C. GranaCorrect
- D. Peroxisome
Explanation. Light-dependent reactions take place within the thylakoid membranes arranged as grana in chloroplasts, where light energy is harvested to generate ATP and NADPH2.
Q12
During photosynthesis, carbon dioxide fixation and carbohydrate synthesis occur in the stroma through the:
- A. Photolysis of water
- B. Light-independent reactionCorrect
- C. Oxidative phosphorylation
- D. Glycolytic pathway
Explanation. The light-independent reaction or Calvin cycle takes place in the fluid matrix (stroma) of chloroplasts, utilizing ATP and NADPH2 to reduce carbon dioxide into glucose.
Q13
The inner mitochondrial membrane forms finger-like infoldings called cristae, which bear ATP-synthesizing complexes known as:
- A. Thylakoids
- B. OxysomesCorrect
- C. Quantasomes
- D. Ribosomes
Explanation. Cristae bear small pinhead-like structures called oxysomes (F1 particles or elementary particles) that contain ATP synthase for synthesizing ATP during respiration.
Q14
Where does glycolysis, the primary stage of respiration common to both aerobic and anaerobic pathways, take place inside the cell?
- A. Mitochondrial matrix
- B. Inner mitochondrial membrane
- C. CytoplasmCorrect
- D. Chloroplast stroma
Explanation. Glycolysis occurs in the cytoplasm of the cell, where a single six-carbon glucose molecule is broken down into two three-carbon molecules of pyruvic acid.
Q15
How is the Respiratory Quotient (RQ) defined during cellular respiration?
- A. Ratio of volume of oxygen consumed to volume of carbon dioxide liberated
- B. Ratio of volume of carbon dioxide liberated to volume of oxygen consumedCorrect
- C. Ratio of ATP molecules synthesized to glucose molecules consumed
- D. Ratio of water molecules formed to oxygen molecules consumed
Explanation. Respiratory Quotient is the ratio of the volume of carbon dioxide released to the volume of oxygen consumed during respiration over a given period.
Frequently asked questions
How many MCQs are there in Plant Anatomy and Plant Physiology?
This chapter has 15 book-back multiple-choice questions, each with the correct answer and a step-by-step explanation.
Are these 10th Standard Science MCQs free to practise online?
Yes. Every question, answer and explanation here is free, and you can also take them as a timed practice test.
Where can I find the Plant Anatomy and Plant Physiology book-back answers?
The correct option for each question is highlighted on this page with a worked explanation, plus a quick answer-key summary at the top.
