Botany and Plant Science

Flowers in which both male and female parts are present are called as bisexual flower. Hibiscus and mustard are examples of bisexual flowers. 

Sterilitzia reginae is the botanical name of the bird of paradise flower. It is called so because of the resemblance of its flowers to birds-of-paradise. In South Africa, it is commonly known as a crane flower.

actinomorphic flower - star shaped or radial- that can be divided in to two identical parts by a plane passing through the center. and is represented by a plus sign contained within a circle.

Hypogynous flowers have the gynoecium situated at the highest position on the thalamus. Among the listed plants, mustard, brinjal, china rose, lupin, gram, bean, chilli, petunia, tomato, and withania are hypogynous, totaling ten.

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). Hence it is also called as a complete or perfect flower. 

Unisexual flower is the one that possesses either stamens or carpels but not both.
Flowers give rise to fruit and seeds.
Thus, the correct answer is option (B), 'Unisexual flowers possess both stamen and pistil'.

After fertilization, the ovary of the flower usually develops into the fruit. Fruits are generally associated with having a sweet taste; however, not all fruits are sweet. The term "fruit" is used for a ripened ovary. In most cases, flowers in which fertilization has taken place will develop into fruits, while unfertilized flowers will not. The fruit encloses the seeds and the developing embryo, thereby providing it with protection. Flowers are bisexual only sometimes. Only some flowers take part in sexual reproduction. Flowers are produced only by angiosperms. 

Flowers are zygomorphic in Gulmohar. Zygomorphic flowers are the flowers which can be divided in one particular plane into two equal halves. The other examples of zygomorphic flowers are pea, bean etc. 

The receptacle is flattened at the top and bears numerous sessile flowers in centripetal order in Capitulum. A capitulum or head, the characteristic inflorescence of the sunflower family (Asteraceae). Depending on the tribe, the inflorescence may consist of ray flowers, disk flowers or both ray and disk flowers. The ovary of each flower is situated below the attachment of the corolla and stamens, a condition referred to as epigynous or inferior. Sunflower bear one or several to many wide, terminal capitula (flower heads) with bright yellow ray florets at the outside and yellow or maroon disc florets inside. Several ornamental cultivars have red-colored ray florets capitulum can be used as an exact synonym for pseudanthium and flower head, however its use is generally but not always restricted to the Asteraceae family. At least one source defines it as a small flower head. Flower head is a special type of inflorescence in which anything from a small cluster to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthia take various forms. The individual flowers of a pseudanthium commonly are called as florets.
Therefore, the correct option is D.

A single naked female flower is surrounded by five scorpioid cyme of male flowers in Cyathium. The inconspicuous male flowers occur in clusters and are reduced to a single red stamen, while the female flower consists of a single ovary (pistil) on a stalk (pedicel). Cyathium inflorescence shows the presence of achlamydeous flowers. 
Achlamydeous flowers are flowers without a perianth. The cyathia are sometimes solitary but are usually in cymes, inflorescences of the second order, in pseudumbels, on dichotomously branched stalks or in so-called simple cymes which consist of one central and two lateral cyathia. The showy, red, modified leaves of these plants are not petals. In fact, they are not even part of the true flowers. They surround clusters of small, greenish, cup-shaped structures called as cyathia. Each cyathium is actually a flower cluster or inflorescence containing unisexual, apetalous male and female flowers. 
Therefore, the correct answer is option B.

"Mono" means single so a monoecious plant is one that bears both male and female sex organs on same plant. The monoecious plant can produce bisexual flowers or unisexual flowers. A dioecious plant is one that bears both male and female sex organs on different plants. A dioecious plant will always produce unisexual flowers.

Rafflesia arnoldii makes the largest single flower in the Angiospermae. It is a parasitic plant. The flower weighs around 15 pounds and can grow up to the height of 3 ft.