Questions: Anatomy of Flowering Plants

Q1 What is a tissue system? Name its three types.

Answer: A tissue system is a group of tissues that share a position in the plant body and work together. Three types are recognised. The epidermal tissue system covers the outside and includes the epidermis, stomata and trichomes. The ground tissue system fills the space between the epidermis and the vascular bundles and includes parenchyma, collenchyma and sclerenchyma. The vascular tissue system is the xylem and phloem, usually travelling as vascular bundles.

Hinglish: Tissue system un tissues ka group hai jo plant body mein ek jagah par hote hain aur milakar kaam karte hain. Teen types hain: epidermal (bahar ki covering), ground (beech ka bhara hua hissa) aur vascular (xylem aur phloem).

Q2 Describe the three kinds of meristematic tissue by their position.

Answer: Apical meristem sits at the tips of roots and shoots and increases the length of the plant. Lateral meristem, also called cambial meristem, lies within older roots and stems and adds to their thickness. Intercalary meristem lies between mature tissues, for example at the base of internodes and leaves in grasses, and it allows regrowth after cutting or grazing.

Hinglish: Apical meristem root aur shoot tip par hota hai aur lambai badhata hai. Lateral meristem purane roots aur stems ke andar hota hai aur motai badhata hai. Intercalary meristem grasses mein internodes aur leaves ke beech hota hai aur kata hua ghaas dobara ugata hai.

Q3 Differentiate parenchyma, collenchyma and sclerenchyma.

Answer: Parenchyma is living, with thin walls and a large central vacuole; it stores food and can photosynthesise where it holds chloroplasts. Collenchyma is also living, but its walls are thickened at the corners with cellulose and pectin, which gives flexible support to young growing parts. Sclerenchyma is dead at maturity, with thick lignified walls and a narrow lumen; it gives hard support, and its forms are long fibres and short sclereids.

Hinglish: Parenchyma living aur thin-walled hoti hai, food store karti hai. Collenchyma bhi living hai par corners par thickening se flexible support deti hai. Sclerenchyma dead aur lignified hoti hai, hard support deti hai, aur uske fibres aur sclereids do forms hain.

Q4 What is the stomatal apparatus and how does a guard cell differ in dicots and grasses?

Answer: The stomatal apparatus is the stomatal pore together with the two guard cells that enclose it and the subsidiary cells around them. In dicots the guard cells are bean-shaped or kidney-shaped. In grasses they are dumb-bell shaped. In both, the guard cells hold chloroplasts and change shape as water moves in and out, which opens or closes the pore.

Hinglish: Stomatal apparatus mein stomatal pore, do guard cells aur unke aas paas ki subsidiary cells aati hain. Dicots mein guard cells bean-shaped hote hain aur grasses mein dumb-bell shaped. Dono mein guard cells chloroplast rakhte hain aur paani ke movement se pore kholte ya band karte hain.

Q5 Describe the structure of a dicot root in section.

Answer: From outside in, the dicot root shows epiblema with root hairs, a multi-layered parenchymatous cortex, a single-layered endodermis with Casparian strips, and a few layers of thick-walled pericycle. Inside the pericycle are two to four separate xylem patches with phloem between them and conjunctive tissue in the gaps; a small pith often fills the centre. All tissues within the endodermis, that is pericycle, vascular bundles and pith, form the stele.

Hinglish: Dicot root mein bahar se andar: epiblema par root hairs, cortex, single-layer endodermis jisme casparian strips, pericycle, phir do se chaar xylem patches, beech mein phloem aur conjunctive tissue, aur chhota pith. Endodermis ke andar ka sab hissa stele kehlata hai.

Q6 How would you tell a monocot stem from a dicot stem in a transverse section?

Answer: A dicot stem shows vascular bundles arranged in a ring, each bundle conjoint and open with endarch protoxylem; it has a collenchymatous hypodermis and medullary rays between the bundles. A monocot stem shows many scattered, conjoint and closed bundles, each with a sclerenchymatous bundle sheath; its hypodermis is sclerenchymatous, medullary rays are absent, phloem parenchyma is absent and water cavities lie inside the bundles.

Hinglish: Dicot stem mein bundles ring mein, conjoint open, endarch protoxylem, collenchymatous hypodermis aur medullary rays. Monocot stem mein bundles scattered, conjoint closed, sclerenchymatous bundle sheath, medullary rays aur phloem parenchyma nahi, aur bundlen ke andar water cavities.

Q7 What is a vascular bundle? Explain the open, closed, radial and conjoint types.

Answer: A vascular bundle is a strand that carries xylem and phloem together. A bundle with cambium between phloem and xylem is open, and it can produce secondary tissue; a bundle without cambium is closed. When xylem and phloem lie on separate radii the arrangement is radial, as in roots, and when both lie on the same radius it is conjoint, as in stems and leaves. A conjoint bundle normally has phloem only on the outer side of the xylem.

Hinglish: Vascular bundle mein xylem aur phloem saath chalte hain. Cambium ke saath open bundle secondary tissue bana sakta hai, cambium ke bina closed. Xylem aur phloem alag radii par hon to radial (roots), ek hi radius par hon to conjoint (stems aur leaves).

Q8 Describe the dorsiventral leaf in section.

Answer: A dorsiventral leaf has an upper adaxial epidermis and a lower abaxial epidermis, both with a cuticle; the lower one usually carries more stomata. The mesophyll between them is of two kinds. Palisade parenchyma lies below the upper epidermis and is made of elongated cells standing side by side. Spongy parenchyma lies below the palisade and reaches the lower epidermis, with rounded cells and large air spaces. Vascular bundles run through the veins and midrib and are wrapped in a bundle sheath.

Hinglish: Dorsiventral leaf mein upper adaxial aur lower abaxial epidermis hoti hai, dono par cuticle, aur stomata neeche zyada. Beech mein palisade parenchyma ke lambe cells upar aur spongy parenchyma ke gol cells neeche air spaces ke saath. Vascular bundles bundle sheath mein bandhe hote hain.

Q9 What are bulliform cells and what do they do?

Answer: Bulliform cells are large, empty and colourless epidermal cells that lie in rows along the veins on the upper surface of a grass leaf. When they take in water and become turgid they keep the leaf surface open. When water stress makes them flaccid they shrink and cause the leaf to roll inwards, which reduces water loss. The cells are a structural answer to a dry spell.

Hinglish: Bulliform cells grasses ki upper epidermis mein veins ke saath large, empty aur colourless cells hoti hain. Paani se turgid hone par leaf surface khuli rehti hai; paani ki kami mein flaccid hokar leaf ko andar mod deti hain, jisse water loss kam hota hai.

Q10 Why is the study of plant anatomy useful?

Answer: Plant anatomy helps identify plant material from small fragments and decide whether an organ is monocot or dicot. It explains functions from structure, as when the cuticle is linked to water conservation, bundle sheath to leaf veins, or bulliform cells to leaf rolling. It is also useful in judging the quality of wood and plant fibres and in understanding how a plant is built for its habitat.

Hinglish: Plant anatomy se chhote fragments se plant identify hota hai aur monocot-dicot ka farq pata chalta hai. Structure se function samajh aata hai, jaise cuticle se water loss rokna, bulliform cells se leaf roll hona. Wood aur fibres ki quality judge karne mein bhi anatomy kaam aati hai.

That completes the ten written answers. The five-question quiz below checks the tissue systems, the stomatal apparatus, root and stem sections and the leaf types.