Sexual Reproduction in Flowering Plants - Class X

Petaloid bracts are present in Bougainvillea. Petaloids are structures resembling petals but actually they are not. The actual flower of the plant is small and generally white, but each cluster of three flowers is surrounded by three or six bracts with the bright colours associated with the plant, including pink, magenta, purple, red, orange, white or yellow.  A bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often (but not always) different from foliage leaves. They may be smaller, larger or of a different color, shape, or texture. Typically, they also look different from the parts of the flower, such as the petals or sepals.

Plant honey is secreted by nectaries. Nectar is a sugar-rich liquid produced by plants in glands called as nectaries, either within the flowers with which it attracts pollinating animals or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide antiherbivore protection. Common nectar-consuming pollinators include bees, butterflies and moths, hummingbirds, and bats.
Therefore, the correct answer is option B.

Cruciferae flowers - The structure of the flowers is extremely uniform throughout the family. They have four free saccate sepals and four clawed free petals, staggered. They can be dissymmetric or slightly zygomorphic, with a typical cross-like arrangement (hence the name Cruciferae). 

The mustard family (Brassicaceae) consists mainly of annual to perennial herbs with watery acrid juices. They bear alternate leaves which lack stipules. The stems are often hairy, with forked or star-shaped (stellate) hairs. The calyx consists of 4 separate sepals and the corolla of 4 petals that are often separable into a narrow claw at the base, expanded into a broader limb at the upper petal end. The androecium is composed of 6 stamens in a unique tetradidynamous arrangement in which there are 4 long stamens and 2 short ones. The gynoecium is syncarpous (of 2 united carpels) containing ovules that are borne along the ovary wall. (This is called parietal placentation.) The ovary is divided internally, but because the partition goes across the carpels instead of between them, its regarded as a false partition (called as a replum) and the fruit is such a strikingly modified capsule that it has a special name, the silique or a silicle if short and squat. Claw is absent in petals of Fabaceae, Solanaceae and Liliaceae. 
Therefore, the correct answer is option A.

Nectaries are the excretory glands (that exude their secretion and do not store it) which are characterized by presence of rich granular cytoplasm in protoplast and conspicuous nucleus.
They lack vacuoles which makes. Large vacuole with inconspicuous cytoplasm and small nucleus are characteristic features of secretory cells that store their secretions. 
Therefore, the correct answer is option C.

Bracts are specialized leaves present in axis of flower. Small, dry, scaly bracts are called as glumes. For example, wheat and grass.
Thus, the correct answer is option B.

Perianth is a collective term for outer parts of calyx and corolla enclosing androecium and gynoecium. This term is used to refer petalideous monocotyledons, in which the calyx and corolla are combined that they can be distinguished from each other.
Thus, the correct answer is option D.

A lodicule is one of two or three small scales at the base of the ovary in a grass flower that represent the corolla, believed to be a rudimentary perianth. For example, wheat (Triticum aestivum).

Corymb : It is a slightly modified raceme in which the peduncle is relatively short while the pedicels of lower flowers are longer so that both young and old flowers are brought to more or less the same level, e.g., Cassz.a sophora.

Monoecious(bisexual)plant bearing either bisexual or unisexual flowers can exhibit both autogamy as well as geitonogamy. Dioecious(unisexual) plants bearing only male or female flowers will not show autogamy or geitonogamy and only xenogamy is possible.

• A flower is a reproductive structure of a flowering plant, which is a morphological and embryological marvel and the site of sexual reproduction.
• Anther is attached to the distal end of the filament of the stamen.
• Androecium (stamens) and gynoecium (pistils) represent essential parts of a flower.
• The number and length of stamens are variable in flowers of different species.

Calyx and corolla are called as accessory whorls. In some plants they are not differentiated from one another, in such case they are termed as perianth.

The sheath or the perianth, of the inflorescense around the seed in the inflorescence is the edible part of the jackfruit. It is yellow shiny part. The perianth is the non-reproductive part of the flower and structure that forms an envelope surrounding the sexual organs, consisting of the calyx and the corolla.
Thus, the correct answer is option C.

Nectary of Euphorbia is an example of secretory tissue. The tissues that are concerned with the secretion of gums, resins, volatile oils, nectar latex and other substances in plants are called as secretory tissues. These tissues are divided into two groups: laticiferous tissues and glandular tissues. 

Stamens are numerous, epipetalous and monadephous. The filaments of all the stamens fuse to form staminal tube, round the style is a characteristic feature of family Malvaceae.

The edible fleshy part of an apple is the thalamus, which develops along with the ovary to form a false fruit (pome). Bracts, cotyledons, and endosperm are parts of flowers or seeds with entirely different functions and locations.

Achlamydeous flowers are those flowers that lack floral envelope. these flowers are also referred to as naked flowers.

The whorl of the flower are differentiated into two categories essential and non-essential whorl and are consists of 

A bisexual flower is a flower that contains all the four whorls such as petals, sepals, the male reproductive structure (stamen) and female reproductive structure (pistil/ carpel). Hence it is also called as a complete or perfect flower. Petunia is a bisexual flower. Thus the correct answer is option A.

Stigma is the part of the female reproductive part in flower where the pollen grain lands after pollination. It is the one who decides the compatibility of pollen with the plant and it is sticky so that is able to hold the pollen strongly.

The flower is a reproductive organ of an angiosperm plant. The typical flowers consist of sepals, petals, stamens, and carpels. A flower having both stamens as well as carpels or pistils is known as a bisexual flower. Flowers that are either staminate (means having stamens) or pistillate (having pistils only) are known as unisexual flowers. Thus the answer is bisexual flowers.

The correct option is A.

Night-blooming flowers rely on nocturnal pollinators like moths and bats. To attract these pollinators in the dark, they typically emit strong scents rather than relying on bright colors.

The perianth is the outermost whorl of a flower which consists of sepals and petals but they are not differentiated. The perianth is represented by membranous scales known as lodicules. The lodicules are situated above and opposite to the superior palea. The number or lodicules maybe 2 or 3 or many or they may be absent. 

• Pollen grains represent the highly reduced haploid male gametophyte generation in flowering plants, consisting of just two or three cells when released from the anthers. Their role is to deliver twin sperm cells to the embryo sac to undergo fusion with the egg and central cell.
•  The female gametophyte of flowering plants, which produces the two female gametes – the egg cell and central cell – for double-fertilization by the two sperm cells of the male gametophyte
  

Unisexual flowers are those which have either the stamen or pistil but never both.
However, Hibiscus has both male and female reproductive organs as stamen and pistil, in the same flower and hence is not unisexual, it is in fact, bisexual.
Thus, the correct answer is option (A).

Monoecious plant species have separate male and female flowers on the same plant. Examples or monoecious plants are maize, birch, coconut and cucurbit. The plants in which male and female flowers are borne on separate individual are referred to as dioecious plants. e.g., papaya, date palm.

Autogamy is possible only when anther and stigma are close together and there is synchrony in pollen release and stigma receptivity. As in case f cleistogamous flowers, the flowers remain closed so that anthers and stigmas are never exposed. The flowers undergo only self pollination. No external pollinating agency is required.

Hydathodes are specialized structures for guttation, salt glands secrete excess salts, and nectaries secrete nectar, making all three active secretory structures. Lenticels are primarily involved in passive gas exchange and respiration rather than secretion.

In Cyathium inflorescence, stamen represents the male flowers and pistil represents a female flower. This type of inflorescence is characterized by the presence of several male flowers (stamen) around a pistillate flower. Cyathium inflorescence is the characteristic feature of Euphorbia genus.

Perianth is represented by membranous scales called as lodicules, they may be 2 or 3 and also interpreted as relictual perianth.

Glumes represent bracts. Glumes are a basal, membranous, outer sterile husk or bract in the flowers of grasses (Poaceae) and sedges (Cyperaceae). A bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger or of a different colour, shape or texture. Typically, they also look different from the parts of the flower, such as the petals or sepals. 
Thus, the correct answer is option A.

Autogamy is pollination within a flower. Chasmogamous flowers are those in which anthers and stigma are exposed. For autogamy, in such a flower to take place, pollen and ovule should mature simultaneously and anther and stigma should lie close to each other.

The non-essential parts of the flower are those that are not involved in the process of fertilization directly. These are called the accessory whorls. The calyx (made up of sepals) and corolla (made up of petals) represent the accessory whorls. In some flowers, the calyx and corolla are not differentiated or distinct. Then the resultant structure is called perianth whose individual units are called tepals.

The flowers of Bougainvillea are bright pink in colour because of the colour of the bracts. These flowers do not have a distinct and differentiated corolla as well as calyx. Three tiny flowers are surrounded by the bracts. These bracts are modified leaves. They protect the flower and attract the pollinators.

When the flowers are laterally borne, then the side of the flower towards the apex of central axis or mother axis is considered to be the posterior side in a floral diagram while the side opposite to the posterior side is towards bracts and is called the anterior side. So, side of the flower towards the bract is called the anterior side.

In some flowers like onion and Asphodelus, the calyx and corolla are not distinct. They are collectively called the perianth. The perianth is an accessory whorl whose individual member is called tepal. Based on the appearance, the tepals can be petaloid (coloured) or sepaloid (green).

When the calyx and corolla are indistinct and undifferentiated, the resultant whorl is called the perianth. 

The term perianth is used to refer to the condition when the calyx and corolla are not differentiated. In grasses, the similar condition is seen by the presence of lodicules, that are situated below the ovary. 

The whorl perianth represents undifferentiated calyx and corolla. Its individual units are called tepals. Tepals can be petaloid if coloured bright or sepaloid if green.

Achlamydeous condition refers to the absence of both the calyx and the corolla. Instead, there is a presence of the whorl called perianth. This type of condition is seen in betel, belonging to the family Piperaceae.

Involucre refers to the group of bracts that are arranged in one or more whorls around the flowers. Example, sunflower.

Flowers are the site of sexual reproduction in a flowering plant. They are a morphological and embryological marvel. The proximal end of the filament of the stamen is attached to the thalamus or the petal of the flower. The number and length of stamens are variable in flowers of different species. The number varies from 3 to 10 in different species. Also, the size of stamens varies largely in different species. Stamen attached to the petal is called as epipetalous. For example, Brinjal.

Bougainvillea flower of the plant is generally white and in which each cluster of 3 flowers is surrounded by 3 or 6 bracts with the bright colors associated with the plant, including purple, magenta, red, pink, white, or yellow, orange,

Tomato belongs to Family Soianaceae. It is a climber. It has actinornorphic flower. 

A flower having sepals, petals, stamens, and pistils are complete; lacking one or more of such structures, it is said to be incomplete. Stamens and pistils are not present together in all flowers. Rose, hibiscus, Oxalis, are a few examples