In a racemose inflorescence, the flowers are borne in
- A.Basipetal succession
- B.Acropetal succession
- C.A single terminal cluster
- D.No definite order
Correct answer
Explanation
The correct answer is B, acropetal succession. In a racemose inflorescence the main axis does not end in a flower but keeps growing, so the lowest flower is the oldest and the youngest buds are at the tip; this upward order is called acropetal, as in radish, mustard and Larkspur. A is wrong because basipetal succession, in which the terminal flower is the oldest and the younger ones appear below it, belongs to the cymose inflorescence, where the main axis ends in a flower, as in Solanum and jasmine. C is wrong because a single terminal cluster is characteristic of a head or capitulum, a special racemose type found in the sunflower, and not of racemose inflorescences generally. D is wrong because both the main types follow a strictly definite order, which is exactly what their names describe. Racemose types also include the spike, the catkin, the spadix, the corymb, the umbel and the head, all of which keep this acropetal order.
Read the full article: Morphology of Flowering Plants: Root, Stem and Flower
Practice Questions
View allWhich of the following plants can survive in extremely saline conditions?
- A.Epiphytes
- B.Halophytes
- C.Xerophytes
- D.Hydrophytes
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Halophytes are plants of saline soils, chiefly the mangroves of tidal creeks and deltas such as Rhizophora and Avicennia, and their morphology is shaped by that habitat: they bear pneumatophores, negatively geotropic breathing roots that rise out of the waterlogged mud, along with stilt and prop roots for support and…
Read the full explanation →The potato is a modification of which plant organ?
- A.Root
- B.Stem
- C.Leaf
- D.Fruit
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The potato is an underground stem tuber, the swollen tip of an underground branch, and the proof is in its morphology: it bears nodes, the depressions called eyes, and each eye carries an axillary bud that can sprout into a new shoot.
Read the full explanation →The edible part of the carrot is a modified
- A.Conical taproot
- B.Fibrous root
- C.Stem tuber
- D.Adventitious root
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The carrot stores food in its primary root, which is broad at the top and tapers steadily to a point, and that shape is described as conical.
Read the full explanation →Prop roots, which hang from spreading branches and give them mechanical support, are a familiar feature of which tree?
- A.Maize
- B.Banyan
- C.Screw pine
- D.Rhizophora
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The banyan's horizontal branches grow so long and heavy that they send down thick aerial roots which reach the soil, thicken into pillars and carry the weight of the branch; these are called prop or pillar roots.
Read the full explanation →Pneumatophores, the negatively geotropic breathing roots, are characteristic of
- A.Mangrove plants such as Rhizophora
- B.Desert plants such as Opuntia
- C.Epiphytic orchids such as Vanda
- D.Parasitic plants such as Cuscuta
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The mud of a tidal swamp is waterlogged and almost free of oxygen, so these plants send up roots that grow vertically out of the soil into the air and take in oxygen through pores; such roots grow against gravity and are therefore called negatively geotropic.
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