krit.club logo

The Wonderful World of Plants - Structure and Functions of a Flower

Grade 6CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

The flower is the reproductive organ of a plant, responsible for producing seeds and fruits.

Sepals (Calyx): These are the outermost green leaf-like structures that protect the flower in its bud stage.

Petals (Corolla): Usually brightly colored and scented to attract insects and birds for the process of pollination.

Stamen (Androecium): The male reproductive part of the flower. It consists of the AntherAnther (which contains pollen grains) and the FilamentFilament (the stalk supporting the anther).

Pistil or Carpel (Gynoecium): The female reproductive part. It consists of three parts: the StigmaStigma (receptive tip), the StyleStyle (elongated tube), and the OvaryOvary (swollen base containing ovules).

Pollination: The process of transfer of pollen grains from the AntherAnther to the StigmaStigma. This can be Self-pollination (within the same flower) or Cross-pollination (between different flowers).

Fertilization: After pollination, the male gamete from the pollen grain fuses with the female gamete (egg) inside the ovule to form a zygote.

Post-fertilization changes: The OvaryOvary develops into a fruit, while the OvulesOvules develop into seeds.

📐Formulae

Stamen=Anther+FilamentStamen = Anther + Filament

Pistil=Stigma+Style+OvaryPistil = Stigma + Style + Ovary

Pollination+FertilizationSeedFormationPollination + Fertilization \rightarrow Seed \, Formation

OvarypostfertilizationFruitOvary \xrightarrow{post-fertilization} Fruit

OvulepostfertilizationSeedOvule \xrightarrow{post-fertilization} Seed

💡Examples

Problem 1:

Identify the male and female reproductive parts in a Hibiscus flower.

Solution:

Male part: StamenStamen; Female part: PistilPistil.

Explanation:

In a Hibiscus flower, the long tube-like structure holds several AnthersAnthers (male) and ends in a five-lobed StigmaStigma (female).

Problem 2:

Differentiate between a Unisexual and a Bisexual flower.

Solution:

Unisexual flowers contain either only StamensStamens or only PistilsPistils. Bisexual flowers contain both StamensStamens and PistilsPistils.

Explanation:

Papaya is an example of a unisexual flower, whereas Rose and Lily are bisexual flowers as they possess both male and female reproductive organs in the same flower.

Problem 3:

What happens to the OvaryOvary after successful fertilization?

Solution:

The OvaryOvary grows in size and ripens to become the fruit.

Explanation:

Once the male gamete fuses with the egg in the ovule, the surrounding ovary wall thickens and matures into the fleshy or dry fruit we consume.