Exams › NEET › Biology › Plant Anatomy
18 questions with worked solutions.
Q1. Cork is used for insulation and acts as shock absorber because
Answer: It is porous
Cork has many tiny pores filled with air. Air is a poor conductor of heat and the porous structure also helps absorb shocks, so cork works well as an insulator and shock absorber.
Q2. The only plant cells without nucleus among the following is
Answer: Xylem vessels
Xylem vessels are dead at maturity, so they lack a nucleus and other cell contents. Cambium cells, root hair cells, and companion cells are living cells and therefore contain a nucleus.
Q3. Which is the living component of xylem?
Answer: xylem parenchyma
Xylem parenchyma is the only living component of xylem at maturity. Tracheids, tracheae, and xylem fibres are dead cells that mainly conduct water or provide support.
Q4. Cork of commerce obtained from Quercus is part of
Answer: Phellem
Cork used in commerce comes from the outer protective tissue called phellem, which is made of dead, suberized cells. Phellogen is the cork cambium that produces cork, while phelloderm is the inner living tissue.
Q5. One of them is absent in closed vascular bundles.
Answer: Cambium
In a closed vascular bundle, cambium is absent because the xylem and phloem are already fully differentiated and there is no meristematic layer between them. Pith and ground tissue may still be present depending on the organ, but cambium is the defining missing part.
Q6. In Brassica oleracea var. capitata (cabbage), the edible part is
Answer: vegetative bud
In cabbage, the edible head is formed by a condensed cluster of immature leaves around a short stem, which is a vegetative bud. It is not a flower structure or a stem alone.
Q7. The tissue is defined as a group of
Answer: Cells which are similar in origin, form and function
A tissue is a collection of cells that are alike in origin and usually work together in a similar way. This matches the idea of cells being similar in origin, form, and function.
Answer: Dead tissue separated by periderm on outerside
Rhytidome is the outer, dead portion of bark formed as successive periderms isolate older tissues from the living stem. Because it lies on the outside of the periderm, it consists of dead tissue.
Q9. A plant with parallel venation is
Answer: Grass
Grass has parallel venation, which is a common feature of monocot plants. The other options are dicots or have different leaf venation patterns.
Q10. Which one is correct about bulliform/ motor cell?
Answer: Both of the above
Bulliform (motor) cells are characteristic of grasses and other monocots. They are large, thin-walled, colorless, vacuolated cells found on the adaxial (upper) epidermis of the leaf.
Q11. Eusporangiate fern is produced from
Answer: Group of sporangial initial cell
Eusporangiate ferns form sporangia from a group of sporangial initial cells, which leads to a larger, thicker-walled sporangium. In contrast, leptosporangiate ferns typically arise from a single initial cell.
Answer: Only A and B
Secondary growth is produced by cambium, which is present in the root of Cycas and the stem of Pinus. Maize and wheat are monocots, so they generally lack secondary growth, and the stem of mango is not included in the keyed correct set here.
Q13. Casparian strips occur in
Answer: Radial walls of endodermis
Casparian strips are found in the endodermis, where they block apoplastic movement and force water and minerals through cell membranes. This selective barrier is located in the radial and transverse walls of endodermal cells.
Q14. Gametophytic plant body is nonvascular in
Answer: Algae and liverworts
The gametophytic plant body in algae and liverworts does not have vascular tissues like xylem and phloem. Ferns, gymnosperms, and angiosperms are vascular plants, so this feature does not fit them.
Answer: Parietal
Parietal placentation means the ovules are attached to the inner wall of the ovary. In a multilocular ovary, this attachment can extend over the entire inner surface, matching the description given.
Q16. The part labelled as 'A' represents the
Answer: Hypocotyl
The hypocotyl is the part of the embryo/seedling axis located between the cotyledons and the root. If label A marks that lower stem-like section, it is the hypocotyl.
Q17. Which tissue is responsible for secondary growth in the plants?
Answer: vascular cambium
Vascular cambium is the lateral meristem responsible for secondary growth because it divides to form secondary xylem and secondary phloem, increasing the plant’s thickness. Xylem and phloem are transport tissues, while cork is part of the protective outer tissue system.
Answer: Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
Monocots generally do not form a vascular cambium, so they do not undergo normal secondary growth. Since the cambium is the tissue responsible for secondary growth, the reason correctly explains the assertion.