NEET Biology Morphology of Flowering Plants MCQs Set 21

Answer: (a) False fruits

Explanation:
1. In some fruits parts other than the ovary, such as the thalamus, also contribute to fruit formation.
2. Such fruits are called false fruits, as in apple, strawberry and cashew.
3. A true fruit develops only from the ovary.

Teacher's Note:
1. False fruit means a fruit that includes accessory floral parts.
2. Remember apple, pear and cashew.

Answer: (a) Gynoecium occupies the highest position, while the other parts are situated below it.

Explanation:
1. Mustard has a hypogynous flower: the gynoecium occupies the highest position on the thalamus while the other floral parts arise below it.
2. In perigynous flowers the other parts are at the rim at the same level, and in epigynous flowers they arise above the ovary.

Teacher's Note:
1. Hypogynous gives a superior ovary.
2. Check the position of the ovary relative to the other floral whorls.

Answer: (b) Bulbil

Explanation:
1. In Agave, vegetative propagation occurs through bulbils, which are fleshy buds that develop into new plants.
2. Rhizomes are underground stems, offsets are short runners of aquatic plants and eyes are buds of potato.

Teacher's Note:
1. Bulbils are the propagules of Agave.
2. Link each propagule with its plant: ginger rhizome, water hyacinth offset.

Answer: (a) (i), (iii) and (iv) only

Explanation:
1. Both mango and coconut are drupes that develop from a monocarpellary ovary.
2. In coconut the mesocarp is fibrous and the endosperm is edible, while in mango the mesocarp is fleshy and edible and the endocarp is hard.
3. So statement (ii) is incorrect and (i), (iii), (iv) are correct.

Teacher's Note:
1. In a drupe the endocarp is stony.
2. The edible part differs between mango and coconut.

Answer: (a) (a) and (d)

Explanation:
1. The pollen grain inside the anther (male gametophyte inside the sporophyte) and the embryo sac inside the ovule are cases of two generations, a gametophyte within a sporophyte.
2. A germinated pollen grain with two male gametes is a single gametophyte, and the seed in the fruit belongs to the sporophyte generation only.

Teacher's Note:
1. In seed plants the gametophyte remains inside the sporophyte.
2. Count generations by nuclear phase, haploid or diploid.

Answer: (b) Inferior ovary

Explanation:
1. Ray florets of the sunflower family are female and their ovary is inferior, lying below the other floral parts.

Teacher's Note:
1. Epigynous flowers have inferior ovaries.
2. The ovary of disc florets is also inferior.

Answer: (a) Plum

Explanation:
1. The ovary is half inferior in perigynous flowers such as plum, rose and peach.
2. Brinjal and mustard are hypogynous with a superior ovary and sunflower is epigynous with an inferior ovary.

Teacher's Note:
1. Perigynous means half inferior ovary.
2. Plum, rose and peach are the common perigynous examples.

Answer: (c) Alstonia

Explanation:
1. Alstonia shows whorled phyllotaxy, with more than two leaves at each node.
2. Mustard and China rose have alternate leaves and Calotropis has opposite leaves.

Teacher's Note:
1. Alternate: mustard, China rose.
2. Opposite: Calotropis, guava.
3. Whorled: Alstonia, Nerium.

Answer: (c) Solanum

Explanation:
1. In Solanum (Solanaceae) the ovary is bicarpellary, syncarpous, and the septum is oblique.
2. Brassica has a bicarpellary ovary with a false septum, Aloe is tricarpellary and Sesbania is monocarpellary.

Teacher's Note:
1. Oblique septum is a feature of Solanaceae.
2. Brassica has the replum.

Answer: (c) Parietal

Explanation:
1. In parietal placentation the ovules develop on the inner wall of the ovary or its peripheral part.
2. In basal, axile and free central types they are on the base, the central axis or the central column respectively.

Teacher's Note:
1. Parietal means wall; Axile means axis.
2. Mustard and Argemone show parietal placentation.

Answer: (d) Ovules develop into embryo sac 86

Explanation:
1. After fertilisation the ovary develops into the fruit, the zygote into the embryo, the central cell into the endosperm and the ovule into the seed.
2. The embryo sac is present before fertilisation and is not formed from the ovule after it.

Teacher's Note:
1. Ovule becomes seed.
2. Ovary wall becomes the pericarp.

Answer: (d) Drupe

Explanation:
1. The coconut is a drupe: it develops from a monocarpellary ovary and has a fibrous mesocarp and a hard endocarp.

Teacher's Note:
1. Drupe examples are mango and coconut.
2. Coconut water is liquid endosperm.

Answer: (c) Dianthus

Explanation:
1. Free central placentation, in which the ovules lie on the central axis of a unilocular ovary, is found in Dianthus and Primrose.
2. Brassica and Argemone have parietal placentation and Citrus has axile placentation.

Teacher's Note:
1. Free central: Dianthus and Primula.
2. Axile: tomato, lemon.

Answer: (a) Pitcher of Nepenthes

Explanation:
1. Thorns of citrus, tendrils of cucumber and flattened phylloclades of Opuntia are modified stems.
2. The pitcher of Nepenthes is a modified leaf.

Teacher's Note:
1. Pitcher is a leaf modification.
2. Tendrils can be stem or leaf modifications depending on the plant.

Answer: (c) Lemon

Explanation:
1. Lemon (Citrus) has axile placentation, with ovules on the central axis of a multilocular ovary.
2. Argemone has parietal, Dianthus has free central and pea has marginal placentation.

Teacher's Note:
1. Marginal placentation is found in pea and other legumes.
2. Axile occurs in China rose, tomato and lemon.

Answer: (d) Rhizome

Explanation:
1. Ginger propagates vegetatively through the rhizome, an underground stem with nodes and buds.
2. Offsets, bulbils and runners are used by other plants.

Teacher's Note:
1. Ginger and turmeric are rhizomatous.
2. Potato is a stem tuber.

Answer: (d) Nucellus

Explanation:
1. The megasporangium is the nucellus of the ovule, the tissue in which the megaspore mother cell lies.
2. The embryo sac is the female gametophyte and the ovule includes integuments too.

Teacher's Note:
1. Nucellus equals megasporangium.
2. Ovule equals megasporangium plus integuments plus funicle.

Answer: (b) Actinomorphic, hypogynous with twisted aestivation

Explanation:
1. The China rose (Hibiscus rosa-sinensis) flower is actinomorphic, hypogynous and has twisted aestivation of the petals.
2. It belongs to Malvaceae.

Teacher's Note:
1. Twisted aestivation occurs in China rose, cotton and Hibiscus.
2. The ovary is superior.

Answer: (b) Axile

Explanation:
1. Tomato and lemon have axile placentation, where the ovary is multilocular and the ovules lie along a central axis.

Teacher's Note:
1. Solanaceae and Rutaceae show axile placentation.
2. Locules arise from the septa.