Questions: Morphology of Flowering Plants

Q1 Describe the regions of a root tip from the apex upward.

Answer: Four regions sit in order. At the apex is the root cap, a thimble-like cover that protects the growing tip. Just above it is the region of meristematic activity, where small thin-walled cells with dense protoplasm divide repeatedly. Above that comes the region of elongation, where cells enlarge and the root grows in length. Farthest from the tip is the region of maturation, where cells differentiate; some of its epidermal cells form root hairs that absorb water and minerals.

Hinglish: Root tip par chaar regions hain: root cap jo tip ko protect karta hai, region of meristematic activity jahan cells divide hote hain, region of elongation jahan cells bade hote hain, aur region of maturation jahan root hairs absorption karte hain.

Q2 How would you distinguish a stem from a root?

Answer: A stem carries leaves at its nodes, has internodes between the nodes, and bears buds that may be terminal or axillary. It grows from the plumule of the embryo. A root has no leaves, nodes or buds, and root hairs are separate epidermal cells near the tip. The stem is the ascending axis that holds the leaves up, and the root is the descending axis that anchors the plant and absorbs water.

Hinglish: Stem par nodes, internodes, leaves aur buds hote hain aur woh plumule se banta hai. Root par leaves, nodes ya buds nahi hote; woh plant ko anchor karti hai aur paani absorb karti hai.

Q3 Explain the three types of phyllotaxy with examples.

Answer: In alternate phyllotaxy one leaf arises at each node, and successive leaves alternate their positions; china rose and mustard are the examples. In opposite phyllotaxy a pair of leaves arises at each node and the two face each other; Calotropis and guava are the examples. In whorled phyllotaxy more than two leaves arise at one node and form a ring; Alstonia is the example.

Hinglish: Alternate mein ek leaf per node, jaise china rose; opposite mein do leaves aamne saamne, jaise Calotropis aur guava; whorled mein do se zyada leaves ek node par ring banaati hain, jaise Alstonia.

Q4 Distinguish between racemose and cymose inflorescence.

Answer: In racemose inflorescence the main axis keeps growing and the flowers open in acropetal order, from the base towards the tip. In cymose inflorescence the main axis ends in a flower and stops growing, so the flowers open in basipetal order, from the tip downwards. The continuing axis versus the terminated axis is the whole difference between the two types.

Hinglish: Racemose mein main axis badhti rehti hai aur flowers base se tip tak khulte hain yaani acropetal. Cymose mein main axis flower par khatam hoti hai aur flowers tip se neeche tak khulte hain yaani basipetal.

Q5 Describe the parts of a typical flower and their arrangement.

Answer: The flower parts sit in four whorls on the thalamus. The calyx, made of sepals, is outermost. The corolla, made of petals, comes next. The androecium, made of stamens, follows, and the gynoecium, made of carpels, is at the centre. Calyx and corolla are accessory organs and androecium and gynoecium are reproductive organs. A flower with both reproductive whorls is bisexual, and one with only stamens or only carpels is unisexual.

Hinglish: Thalamus par chaar whorls hote hain: calyx (sepals), corolla (petals), androecium (stamens) aur gynoecium (carpels). Pehle do accessory aur baaki do reproductive hain. Dono reproductive whorls hon to flower bisexual hota hai.

Q6 What are the types of aestivation? Give one example of each.

Answer: Valvate aestivation has members touching at the margins without overlapping, as in Calotropis. Twisted aestivation has one margin overlapping the next all round the whorl, as in china rose and cotton. Imbricate aestivation has margins overlapping without a fixed direction, as in Cassia and gulmohur. Vexillary aestivation has a large standard petal overlapping two wings, which overlap two keel petals, as in pea and bean.

Hinglish: Valvate (Calotropis), twisted (china rose, cotton), imbricate (Cassia, gulmohur) aur vexillary (pea, bean). Vexillary mein standard petal wings ko aur wings keel ko dhakti hain.

Q7 Explain the parts of a stamen and a carpel.

Answer: A stamen has a stalk called the filament and an anther. The anther is usually bilobed, and each lobe holds two pollen sacs where pollen grains form. A carpel has a stigma, which receives pollen, a style, which connects the stigma to the ovary, and an ovary, which holds the ovules. After fertilisation the ovules become seeds and the ovary becomes the fruit.

Hinglish: Stamen mein filament aur anther hota hai; anther bilobed hota hai aur har lobe mein do pollen sacs hote hain. Carpel ke teen parts stigma, style aur ovary hain. Ovules seeds banti hain aur ovary fruit.

Q8 What is placentation? Name its types with examples.

Answer: Placentation is the way ovules are placed inside the ovary. In the marginal kind, a ridge of placenta runs along the ventral suture and the ovules sit on it, as in pea. In axile placentation the ovules sit on an axial placenta in a many-chambered ovary, as in china rose and tomato. In parietal placentation the ovules sit on the inner wall and a false septum splits the ovary, as in mustard. In free central placentation the ovules sit on a central axis with no septa, as in Dianthus. In basal placentation a single ovule sits on a placenta at the base, as in sunflower and marigold.

Hinglish: Placentation ovules ke arrangement ka naam hai. Marginal (pea), axile (china rose, tomato), parietal (mustard), free central (Dianthus) aur basal (sunflower). Placenta ki position dekhkar naam decide karo.

Q9 Why is a maize grain called a fruit and not a seed?

Answer: In maize the seed coat is membranous and fused with the fruit wall, so the two cannot be separated. The whole grain therefore carries a fruit wall around it, which makes it a fruit. Inside, the grain shows the endosperm, the aleurone layer, the scutellum, the coleoptile, the plumule, the radicle and the coleorhiza that belong to the seed.

Hinglish: Maize mein seed coat aur fruit wall fused hote hain, isliye grain ke bahar fruit wall hoti hai aur use fruit kehte hain. Andar endosperm, aleurone layer, scutellum, coleoptile, plumule, radicle aur coleorhiza hote hain.

Q10 Write the semi-technical description of a Solanaceae flower.

Answer: The flower is bisexual, actinomorphic and pentamerous. The calyx has five sepals and is gamosepalous, persistent and valvate. The corolla has five petals and is gamopetalous and valvate. The androecium has five stamens that are epipetalous. The gynoecium is bicarpellary, syncarpous, with a superior ovary, two locules, a swollen placenta and many ovules in axile arrangement. The fruit is a berry or a capsule, and the seeds are many and endospermic.

Hinglish: Solanaceae flower bisexual, actinomorphic aur pentamerous hota hai. Calyx mein five sepals gamosepalous, corolla mein five petals gamopetalous, androecium mein five epipetalous stamens, aur gynoecium bicarpellary, syncarpous, superior ovary, do locules aur axile placentation wala hota hai. Fruit berry ya capsule hota hai.

That completes the ten written answers. The five-question quiz below checks the root tip, venation, inflorescence, aestivation and the parts of a seed.