Tag: basics of leaf and flower

Petaloid bracts are present in Bougainvillea. Petaloids are structures resembling petals but actually they are not. The actual flower of the plant is small and generally white, but each cluster of three flowers is surrounded by three or six bracts with the bright colours associated with the plant, including pink, magenta, purple, red, orange, white or yellow.  A bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often (but not always) different from foliage leaves. They may be smaller, larger or of a different color, shape, or texture. Typically, they also look different from the parts of the flower, such as the petals or sepals.

Plant honey is secreted by nectaries. Nectar is a sugar-rich liquid produced by plants in glands called as nectaries, either within the flowers with which it attracts pollinating animals or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide antiherbivore protection. Common nectar-consuming pollinators include bees, butterflies and moths, hummingbirds, and bats.
Therefore, the correct answer is option B.

Cruciferae flowers - The structure of the flowers is extremely uniform throughout the family. They have four free saccate sepals and four clawed free petals, staggered. They can be dissymmetric or slightly zygomorphic, with a typical cross-like arrangement (hence the name Cruciferae). 

The mustard family (Brassicaceae) consists mainly of annual to perennial herbs with watery acrid juices. They bear alternate leaves which lack stipules. The stems are often hairy, with forked or star-shaped (stellate) hairs. The calyx consists of 4 separate sepals and the corolla of 4 petals that are often separable into a narrow claw at the base, expanded into a broader limb at the upper petal end. The androecium is composed of 6 stamens in a unique tetradidynamous arrangement in which there are 4 long stamens and 2 short ones. The gynoecium is syncarpous (of 2 united carpels) containing ovules that are borne along the ovary wall. (This is called parietal placentation.) The ovary is divided internally, but because the partition goes across the carpels instead of between them, its regarded as a false partition (called as a replum) and the fruit is such a strikingly modified capsule that it has a special name, the silique or a silicle if short and squat. Claw is absent in petals of Fabaceae, Solanaceae and Liliaceae. 
Therefore, the correct answer is option A.

Nectaries are the excretory glands (that exude their secretion and do not store it) which are characterized by presence of rich granular cytoplasm in protoplast and conspicuous nucleus.
They lack vacuoles which makes. Large vacuole with inconspicuous cytoplasm and small nucleus are characteristic features of secretory cells that store their secretions. 
Therefore, the correct answer is option C.

Bracts are specialized leaves present in axis of flower. Small, dry, scaly bracts are called as glumes. For example, wheat and grass.
Thus, the correct answer is option B.

Perianth is a collective term for outer parts of calyx and corolla enclosing androecium and gynoecium. This term is used to refer petalideous monocotyledons, in which the calyx and corolla are combined that they can be distinguished from each other.
Thus, the correct answer is option D.

A lodicule is one of two or three small scales at the base of the ovary in a grass flower that represent the corolla, believed to be a rudimentary perianth. For example, wheat (Triticum aestivum).

Corymb : It is a slightly modified raceme in which the peduncle is relatively short while the pedicels of lower flowers are longer so that both young and old flowers are brought to more or less the same level, e.g., Cassz.a sophora.

Application of GA can induce flowering in long day plants. It has no favourable effect on size of flower and fruit in certain plants. The genetically dwarf plants can be made tall by application of GA.