Androecium MCQ - Practice Questions with Answers

Parts of a Flower - Androecium

• Androecium is the male reproductive whorl of the flower. 
• It is made up of stamens. 
• Each stamen is made up of filament and anther.
• Each anther is generally bilobed with four pollen sac or microsporangia.
• The pollen grains are produced in pollen sac.
• A sterile stamen is called staminode.

I. Cohesion of Androecium:

• When stamens are united with each other, it is called cohesion of androecium. It is of following three types:

1. Adelphous: The stamens are fused by their filaments only. The anthers are free. When the fusion of filament produces a single group, it is called monadelphous, e.g., Hibiscus. When two groups are formed, it is called diadelphous, e.g. pea. When many groups are produced, it is called polyadelphous, e.g., Citrus.
2. Syngenesious/Synantherous: Stamens are fused by anthers only. Filaments are free. E.g., sunflower.
3. Synandrous: Stamens are fused both in the region of filaments and anthers. E.g., cucumber.
    

II. Adhesion of Androecium:

• When stamens are attached to other members of the flowers, it is called the adhesion of androecium.

1. Epipetalous: When stamens are attached to the petals, they are called epipetalous, for example, brinjal.
2. Epiphyllous: When stamens are attached to the perianth, they are called epiphyllous, for example, lily.

III. Fixation of Anthers:

1. If the stamens are shorter than corolla, they are called inserted.
2. If the stamens protrude out of the corolla, they are called exserted.
3. When anthers are attached to the base of the filament, it is called basifixed/innate, e.g., Brassica.
4. When filament run throughout the length of the anther or become continuous with the connective, it is called adnate, e.g., magnolia, ranunculus, etc.
5. When filament is attached at the dorsal side of the anther, it is called dorsifixed, e.g., citrus.
6. When filament in the middle of the connective, in such a way that the anther can swing freely, it is called versatile, e.g., grasses.

• When stamens are free and not fused with other parts, they are called polyandrous.
• When the stamens are unequal in length such that there are 2 long and 2 short, they are called didynamous, for example, ocimum.
• When the stamens are unequal in length such that there are 4 long and 2 short, they are called tetradynamous, for example, Brassica.
• When all the stamens are of different length, it is called heterostemony, e.g., Cassia.
• When all the stamens are of the same length, it is called homostemous
• According to the number, stamens can be monandrous, diandrous, triandrous, tetrandrous and so on.