Prepare for NEET Biology Morphology of Flowering Plants with MCQs & PYQs on NEET.GUIDE. Get free practice, previous year questions, and expert explanations of plant structures.
A mutation in a plant affects the development of its palisade parenchyma, significantly reducing the number and length of these cells. Which of the following would be the MOST DIRECT consequence of this mutation on photosynthesis?
Increased rate of photorespiration due to higher oxygen concentration.
Reduced CO2 fixation by RuBisCO in the mesophyll cells.
Decreased light absorption and reduced efficiency of the light-dependent reactions.
Impaired transport of sugars from the source to the sink.
Which structural feature of guard cells facilitates their function in stomatal regulation MOST effectively?
Uniformly thickened cell walls.
Radially oriented cellulose microfibrils in the cell walls.
Large central vacuole for water storage.
Presence of chloroplasts for photosynthesis.
A plant exhibits a unique inflorescence where the peduncle is flattened and bears sessile flowers in a centripetal fashion. Small, scaly bracts are present, and the oldest flowers are located at the periphery. This type of inflorescence is MOST accurately classified as a:
Cyathium
Hypanthodium
Capitulum
Verticillaster
In a hypothetical plant species, the inflorescence exhibits a unique combination of features: a condensed cymose head surrounded by an involucre of brightly colored bracts that mimic petals. The individual flowers within the head are inconspicuous. Which existing inflorescence type does this MOST closely resemble, and what evolutionary advantage might this unique structure offer?
Cyathium; protection from herbivores
Hypanthodium; trap for pollinators
Capitulum; enhanced pollinator attraction
Verticillaster; increased seed dispersal
Differentiating between a thyrse and a mixed inflorescence can be challenging. Which of the following statements BEST distinguishes a thyrse from a truly mixed inflorescence?
A thyrse always has a determinate main axis, while a mixed inflorescence always has an indeterminate main axis.
A thyrse has a cymose arrangement of racemose units, while a mixed inflorescence combines different inflorescence types randomly.
A thyrse always has brightly colored bracts, while a mixed inflorescence lacks bracts.
A thyrse has a racemose arrangement of cymose units, while a mixed inflorescence combines different inflorescence types in a less predictable pattern.
A rare orchid species exhibits a highly specialized pollination mechanism. Its labellum mimics the pheromones and appearance of a specific female wasp species, attracting the males for pseudocopulation. Which of the following floral adaptations is LEAST likely to be observed in this orchid?
Abundant nectar production within the spur
Precise positioning of pollen packets (pollinia) for attachment to the male wasp
Flower color and shape closely resembling the female wasp
Flowering period synchronized with the mating season of the wasp
A mutant plant exhibits stunted root growth and reduced gravitropic response. Microscopic analysis reveals disorganized columella cells in the root cap. Which of the following is the MOST likely cause of this phenotype?
Increased production of cytokinin in the root tip
Disruption of amyloplast sedimentation and auxin redistribution
Overexpression of genes involved in cell elongation
Enhanced sensitivity to ethylene
The polyphyletic grouping of organisms is based on:
Shared ancestral characteristics.
Homologous characteristics derived from a common ancestor.
Analogous characteristics due to convergent evolution.
A combination of ancestral and derived characteristics.
A scientist is constructing a phylogenetic tree using cladistics. Which type of character would be considered the most informative for resolving evolutionary relationships within a group?
Plesiomorphy
Symplesiomorphy
Autapomorphy
Synapomorphy
A unique characteristic of the pomes like apple and pear is the fleshy edible part developing from:
Hypanthium
Ovary wall
Receptacle
Mesocarp
