31 Years NEET Previous Year Questions: Morphology of Flowering - 2 - NEET MCQ

The flowers in Fabaceae family are perigynous, zygomorphic.

The perianth commonly consists of a calyx and corolla of 5 segments each.

The petals are overlapping (imbricate) in bud with the posterior petal (called as the banner or flag) outermost (i.e., exterior) in position. The two lowermost petals are joined together called as the keel petals. The lateral petals are often called as the wings.

This arrangement of floral whorls is called as vexillary aestivation.

So, the correct answer is 'Fabaceae'.

Topic in NCERT: Aestivation

Line in NCERT: "In pea and bean flowers, there are five petals, the largest (standard) overlaps the two lateral petals (wings) which in turn overlap the two smallest anterior petals (keel); this type of aestivation is known as vexillary or papilionaceous."

Cymose infloresence in present in Solanum.  Cymose inflorescence is the name of determinate or definite inflorescence in which the tip of the main axis terminates in a flower and further growth continues by one or more lateral branches which also behave like the main axis.

Topic in NCERT: MORPHOLOGY OF FLOWERING PLANTS

Line in NCERT: "Inflorescence: Solitary, axillary or cymose as in Solanum"

Topic in NCERT: placentation

Line in NCERT: "When the placenta is axial and the ovules are attached to it in a multilocular ovary, the placentaion is said to be axile, as in china rose, tomato and lemon."

Free central placentation occurs in  Dianthus and Primula in which ovules are borne on central axis and septa are absent.

Topic in NCERT: placentation

Line in NCERT: "When the ovules are borne on central axis and septa are absent, as in Dianthus and Primrose the placentation is called free central."

Whorled phyllotaxy is a feature of Nerium and Alstonia. In Alstonia five leaves are present in a whorl while in Nerium three leaves  are present in a whorl.

Topic in NCERT: Phyllotaxy

Line in NCERT: "If more than two leaves arise at a node and form a whorl, it is called whorled, as in Alstonia."

The ovary is half-inferior in flowers of peach.

Topic in NCERT: Epigynous Flowers

Line in NCERT: "If gynoecium is situated in the centre and other parts of the flower are located on the rim of the thalamus almost at the same level, it is called perigynous. The ovary here is said to be half inferior, e.g., plum, rose, peach."

When a flower can be divided into two similar halves only in one particular vertical plane, it is zygomorphic, e.g. pea, gulmohar, bean, etc.

Topic in NCERT: THE FLOWER

Line in NCERT: "When it can be divided into two similar halves only in one particular vertical plane, it is zygomorphic, e.g., pea, gulmohur, bean, Cassia."

Correct Answer :- a

Explanation :

Chilli (Capsicum annum) belongs to family-Solanaceae. In this family, flower is actinomorphic, complete and bisexual; calyx has five sepals which are gamosepalous showing valvate aestivation; corolla has five petals which are polypetalous showing valvate aestivation; androecium has five free stamens (polyandrous) but epipetalous; gynoecium is bicarpellary, syncarpous, bilocular with superior ovary having axile placentation.

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Topic in NCERT: Flower Structure and Symmetry

Line in NCERT: "Chilli: Flowering plants exhibit enormous variation in shape, size, structure, mode of nutrition, life span, habit and habitat. They have well developed root and shoot systems. In symmetry, the flower may be actinomorphic (radial symmetry) or zygomorphic (bilateral symmetry). When a flower can be divided into two equal radial halves in any radial plane passing through the centre, it is said to be actinomorphic, e.g., mustard, datura, chilli."

Hibiscus belongs to Malvaceae family. It possess numerous stamens that are called monadelphous.

Topic in NCERT: Androecium

Line in NCERT: "When stamens are attached to the petals, they are epipetalous as in brinjal, or epiphyllous when attached to the perianth as in the flowers of lily. The stamens in a flower may either remain free (polyandrous) or may be united in varying degrees. The stamens may be united into one bunch or one bundle (monoadelphous) as in china rose, or two bundles (diadelphous) as in pea, or into more than two bundles (polyadelphous) as in citrus."

A flower in which floral parts arise from around the ovary is called perigynous. In this, the ovary is half inferior and half superior. It can be seen in the flowers of plum, peach etc.

Topic in NCERT: Position of floral parts on thalamus

Line in NCERT: "The ovary here is said to be half inferior, e.g., plum, rose, peach."

Keel is the characteristic of the flowers of family papilionaceae. For example, bean, gram, pea etc.
The flowers of this family have butterfly shaped corolla. The outermost petals of these flowers is the largest and is called vexillum, the two largest petals are similar and have wings and the two anterior petals called keel are fused enclosing stamens and carpels.
Line in Ncert :nIn pea and bean flowers, there are five petals, the largest (standard) overlaps the two lateral petals (wings) which in turn overlap the two smallest anterior petals (keel); this type of aestivation is known as vexillary or papilionaceous.

In basal type of placentation, the ovary is unilocular with a single ovule. In this the placenta is at the base of the ovary. It is seen in Polygonum.

Topic in NCERT: placentation

Line in NCERT: "In basal placentation, the placenta develops at the base of ovary and a single ovule is attached to it, as in sunflower, marigold."

Axile placentation is found in multi carpellary syncarpous gynoecium. The margin of carpels growing inward, fuse and meet in the centre of the ovary. Axis forms in the centre of the ovary, thus ovary becomes multi-chambered. The ovules are borne at the central axis. The number of these chambers are equal to the number of carpels. For example, potato, china rose, onion, lemon, orange and tomato.

Topic in NCERT: placentation

Line in NCERT: "When the placenta is axial and the ovules are attached to it in a multilocular ovary, the placentation is said to be axile, as in china rose, tomato and lemon."

The given floral formula is of tobacco. It belong to the family Solanaceae. The flower is actinomorphic, bisexual and having superior ovary. Soyabean and sunhemp have monocarpellary pistil and tulip has trimerous flower and perianth.

Topic in NCERT: floral formula

Line in NCERT: "Floral Formula: O̅ K(5) C (5) A5 G(2)"

Pentamerous, actinomorphic flowers, bicarpillary ovary with oblique septa, fruit is capsule or berry are the characteristic features of family Solanaceae.
In Brassicaceae – dimerous or tetramerous, actinomorphic but sometimes zygomorphic flower, bicarpellary ovary with a false septum (called replum), fruit is siliqua or silicula.
Lilicaeae – Trimerous, actinomorphic flower, tricarpillary, syncarpous ovary, fruit is berry or capsula.
Asteraceae – Pentamerous, actinomorphic or zygomorphic flower, bicarpillary, syncarpous, unilocular ovary, fruit is cypsella.

Topic in NCERT: Floral Characters

Line in NCERT: "Flower: bisexual, actinomorphic" "Fruits: berry or capsule" "It is a large family, commonly called as the ‘potato family'." "It is widely distributed in tropics, subtropics and even temperate zones." "Floral Characters" "Inflorescence: Solitary, axillary or cymose as in Solanum" "Flower: bisexual, actinomorphic" "Calyx: sepals five, united, persistent, valvate aestivation" "Corolla: petals five, united; valvate aestivation" "Androecium: stamens five, epipetalous" "Gynoecium: bicarpellary obligately placed, syncarpous; ovary superior, bilocular, placenta swollen with many ovules, axile"