Class 9 SELINA Solutions Biology Chapter 4 - The Flower
The Flower Exercise Ex. 1
Solution A
1. (d) large colourful bracts
2. (d) It has all the four whorls.
3. (c) Ovary
4. (c) Ovule
5. (d) Androecium and gynoecium
Solution B.1
|
Column A |
Column B |
|
(a) Polyadelphous |
(i) Bombax |
|
(b) Pollen grains |
(ii) Pollen sac |
|
(c) Free petals |
(iii) Polypetalous |
|
(d) Non-essential |
(iv) Calyx, corolla |
|
(e) Sweet fragrant fluid |
(v) Nectar |
Solution C.1
(a) Incomplete flower - If one or more sets of floral structures are missing, the flower is called incomplete flower. E.g. American elm.
(b) Staminate flower - A unisexual flower which contains only the stamens, i.e., male parts of a flower is called male or staminate flower. E.g. Eastern cottonwood.
(c) Pistillate flower - A flower which contains only the carpels, i.e., female parts of a flower is called female or pistillate flower. E.g. Date palm.
(d) Bisexual flower - A flower which contains both stamens and carpels is called bisexual or hermaphrodite flower. E.g. Hibiscus.
Solution C.2
(a) Flower and Inflorescence
|
Flower |
Inflorescence |
|
Flower is a specialized shoot in which the leaves are modified into floral structures. |
Inflorescence is the mode of arrangement of flowers on the axis of the plant. |
(b) Petals and Petaloid sepals
|
Petals |
Petaloid sepals |
|
Petals are non-essential parts of a flower which help in protection of reproductive parts and make the flower attractive for pollination. |
Undifferentiated petals and sepals together form the perianth. When perianth is non-green, it is called a petaloid. |
(c) Polyandrous and polyadelphous androecium
|
Polyandrous androecium |
Polyadelphous androecium |
|
In polyandrous androecium, filaments of the stamens are free. |
In polyadelphous androecium, filaments of the stamens are united in several groups. |
Solution C.3
(a) Placenta:
Location: Cushion or swollen region in the ovary
Function: Gives origin to ovules
(b) Thalamus:
Location: Tip of the flower stalk
Function: Bears all the parts of the flower
(c) Anther:
Location: Part of the stamen
Function: Produces male gametes or pollen grains
(d) Stigma:
Location: Terminal knob-like part
Function: Serves as the landing place for pollen grains during pollination
Solution D.1
Types of androecium in flowers:
1. Polyandrous: When the stamens of a flower are free, the condition is called polyandrous.
2. Monadelphous: When the filaments of anthers in a flower are fused into one group, the condition is called monadelphous.
3. Diadelphous: When the filaments of anthers in a flower are fused into two groups, the condition is called diadelphous.
4. Polyadelphous: When the filaments of anthers in a flower are fused into more than two groups, the condition is called polyadelphous.
Solution D.2
(a) China rose: Monadelphous
(b) Bombax: Polyadelphous
(c) Pea: Diadelphous
Solution E.1
(a) Figure A represents stamen. Stamens collectively form Androecium.
(b) Contents of the pollen sacs in B are male gametes.
(c) The contents of the pollen sacs would come out through agents like air, wind, insects leading to pollination in flowers.
Solution E. 2
When a flower arises in the axil of a leaf-like structure, this structure is known as bract. Because bracts are large and brightly coloured structures, they are often mistaken for petals. This helps to attract insects for pollination.
Solution E. 3
| Condition of androecium | Explanation | Example of flower |
| Monadelphous | Filaments of the anthers in a flower are fused into one group | Hibiscus |
| Diadelphous | Filaments of the anthers in a flower are fused into two groups | Pea |
| Polyadelphous | Filaments of the anthers in a flower are fused into more than two groups | Bombax |