Morphology of flowering plants practice · Mixed difficulty

Option C (cotton) is correct because scarification, which involves weakening the seed coat, is particularly effective for seeds with hard or impermeable seed coats like those of cotton.

Option B (Lilium) is correct because Lilium (lily) exhibits a scaly bulb stem modification, where the bulb consists of overlapping scales.

Option D (Marginal) is correct because sweet pea exhibits marginal placentation, where the placenta forms a ridge along the ventral suture of the ovary.

The correct answer is C (5) because Spongilla, Taenia, and Pleurobranchia exhibit asymmetry or bilateral symmetry, while Adamsia, Gorgonia, Cucumaria and Ophiura show radial symmetry similar to actinomorphic flowers.

The correct answer is C (The flower may develop in the axis of a small leaf - like structure called bract.) because the presence of a bract supports the idea that a flower is a modified shoot.

Correct Answer + Core Reason: Either (a) or (b). Both Thalamus and Receptacle can refer to the pedicel of the flower.

Step-by-Step Solution:

Step 1: Define the terms:
- Pedicel: The stalk of a flower.
- Thalamus: The expanded end of the pedicel where floral organs are attached; also called the receptacle.
- Receptacle: The expanded end of the pedicel where floral organs are attached; also called the thalamus.

Step 2: Analyze the options:
- Thalamus and receptacle are essentially the same structure.

Step 3: Therefore, the pedicel of a flower can be referred to as either the thalamus or the receptacle.

Why other options are wrong:
- Option A: Thalamus alone is not entirely correct as receptacle is also used.
- Option B: Receptacle alone is not entirely correct as thalamus is also used.
- Option C: Both (a) and (b) is not entirely correct because the question asks what the pedicel is called, not the structure that holds the floral parts.

Key Concepts:
- Flower morphology
- Thalamus/Receptacle
- Pedicel

Memory Aids:
- Thalamus and receptacle are interchangeable terms.

Quick Tips:
- Understand the basic structure of a flower and the terms associated with it.

Option C (Maize – Perispermic seed) is correct because Maize is an endospermic seed, not perispermic. Perisperm is derived from the nucellus, while endosperm is derived from the primary endosperm nucleus.

Option A (Four) is correct because Aloe, Tulip, Onion, and Colchicum Autumnale belong to families with six tepals and six epitepalous stamens.

Option A (Pisum) is correct because it exhibits all the mentioned floral characteristics: zygomorphic flower, vexillary aestivation, diadelphous androecium, and marginal placentation, which are characteristic features of the Fabaceae family to which Pisum belongs.

Option A is correct because parthenocarpy (fruit development without fertilization) is undesirable in nut crops where the seed is the edible part.

Option B (Epiphytes) is correct because velamen tissue is a specialized tissue found in the roots of epiphytes, which helps them absorb moisture from the air.

Option A is correct because both the assertion (opposite phyllotaxy in Calotropis and guava) and the reason (pair of leaves at each node) are true, and the reason correctly explains the assertion.

Option D (All of these) is correct because natural systems of classification consider morphological, anatomical, cytological, embryological, physiological, and reproductive characters.

Option A (Crotalaria juncea) is correct because Crotalaria juncea is the binomial name for sunnhemp, a fiber crop.

Option B (Sweet potato) is correct because sweet potato has adventitious roots that become swollen and store food.

Option A (All are correct except c) is correct because Okra has a tap root system, stipulated leaves with alternate phyllotaxy, and a schizocarp type of fruit, but its flowers are actinomorphic, not zygomorphic.

The correct answer is B (Only xylem of the host) because Striga's haustoria primarily connect to the host plant's xylem to extract water and nutrients.

Option D (II and III) is correct. Pneumatophores are seen in Rhizophora, and adventitious roots are seen in the banyan tree.

Option D (Both 2 and 3) is correct because pneumatophores are negatively geotropic (grow against gravity) and positively phototropic (grow towards light) and aerotropic (grow towards air).

Option D (Peduncle) is correct because the inflorescence axis, which supports the flowers, is called the peduncle.

Option B is correct because in creepers, leaves are produced upon the nodes, and adventitious roots arise from the nodes, but the reason is not the correct explanation of the assertion.

Option D (Small and anterior) is correct because in Fabaceae, the keel petals are the two innermost petals, which are small and fused, forming a boat-shaped structure located anteriorly.

Option A (Coconut, almond and mango) is correct because all three are drupe fruits.

Option B (Tap root) is correct because the tap root system develops directly from the radicle of the seedling.

Option B (Hilum) is correct because the hilum is the scar on the seed where it was attached to the placenta.

Option B (Treating the plants with low concentrations of gibberellic acid and auxins) is correct because gibberellic acid and auxins can induce parthenocarpy, resulting in seedless tomato fruits.

Option B (Reticulate venation) is correct because both Smilax and Colocasia, being dicotyledonous plants, typically exhibit reticulate venation in their leaves.

Option B (Cotyledon) is correct because cotyledons act as storage organs and provide nourishment to the developing seedling, thus serving as a sink.

Option B is correct because the primary function of an inflorescence is to facilitate the formation of more fruit by presenting flowers in a way that enhances pollination.

Option D (Pea – Single stamen in a flower) is correct because Pea (Pisum sativum) has diadelphous stamens (9 fused and 1 free), not a single stamen.