December 16, 2015

Junior Inter Botany Imp 4 Marks Questions from Taxonomy of Angiosperms

Q: Write a brief note on semi technical description of a typical flowering plant.
A: Description of parts of a flowering plant is necessary for characterization, identification and classification of plants. Technical terms are used to describe the habit, habitat, vegetative characters (roots, stem and leaves) and floral characters like inflorescence, flower in general and detail, fruit, seed, pollination etc.

A typical flowering plant is described using technical terminology as follows:
Habit: Herb/ Shrub/ Tree/ Climber etc.
Habitat: Mesophyte/ xerophytes/ hydrophyte etc.
Vegetative characters:
Root: Taproot/ Fibrous root/ Modifications if any.
Stem: Woody/ herbaceous/ climber/ creeper etc
Leaf: Radical/ cauline/ venation/ phyllotaxy

Floral characters:
Inflorescence: Position and type
Flower: general description like presence or absence of bracts, bracteoles etc, merosity, sexuality, symmetry and type based on position of the ovary.
Calyx: No. of sepals, union, aestivation.
Corolla: No. of petals, union, aestivation etc.
Androecium: No. of stamens, their union, anthers etc.
Gynoecium: No. and union of carpels, No. of
locules, position of ovary, placentation etc.
Pollination: Self or cross pollination, contrivances and mechanisms.
Fruit: type
Seed: Dicot or monocot, endospermic or non endospermic.

Q: Describe the non-essential floral parts of plants belonging to Fabaceae.
A: Calyx and corolla are the non-essential floral parts. In Fabaceae the calyx and corolla show the following features:
Calyx: Sepals five, gamosepalous (united), valvate or imbricate aestivation, odd sepal

Corolla: Five petals, polypetalous (free), papilionaceous corolla with one large standard petal, two lateral wing petals and two anterior fused petals called keel petals. The keel petals enclose essential organs. The odd petal is posterior. Vexillary or descendingly imbricate aestivation.

Q: Give an account of floral diagram.
A: Floral diagram and floral formula are used to describe the flower precisely.
Floral diagram gives information about the number of parts of a flower, their arrangement and interrelationships with one another.
The axis represents the posterior side and indicated as a dot or circle on the top of the floral diagram.

The bract represents the anterior side and indicated at the bottom of the floral diagram.
If bracteoles are present they are indicated beside the bract.
The four whorls of a flower calyx, corolla, androecium and gynoecium are indicated as
successive whorls from outside to inside.
The outermost whorl is the calyx and the innermost whorl represents gynoecium.
Floral formula is usually written below the floral diagram to describe the flower with
symbols and numbers.

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