ICSE Solutions for Chapter 4 The Flower Class 9 Biology Selina
Progress Check
1. Mention if the following statements are true (T) or false(F)
(i) Flowers can be complete or incomplete. T/F
(ii) A flower typically has six floral whorls. T/F
(iii) Bracts are usually green, but sometimes large and colorful. T/F
(iv) Nasturtium has nectaries. T/F
(v) Stamens and carpels are the male and female parts T/F
(vi) The prefix “gamo-“ is used whenever any of the floral whorls are used. T/F
(vii) Stigma may be simple or divided into two or more lobes. T/F
(viii) Papaya is monoecious plant. T/F
Solution
(i) The statement is true
(ii) The statement is false. A flower has four whorls.
(iii) The statement is true
(iv) The statement is true
(v) The statement is false. Stamens are carpels are the male and female parts respectively of the flower
(vi) The statement is true
(vii) The statement is true
(viii) The statement is false. Papaya is a dioecious plant.
A. Multiple Choice Type
1. Bougainvillea flower is an example of
(a) Incomplete flower
(b) Having a large nectary
(c) Water pollination
(d) Large colorful bracts
Solution
(d) Large colorful bracts.
Bougainvillea is large, coloured bracts bearing the flowers.
2. A flower is said to be complete when:
(a) It has the corolla and calyx
(b) It has the corolla and gynoecium
(c) It has the androecium and gynoecium
(d) It has all the four whorls.
Solution
(d) It has all the four whorls.
The four whorls are: calyx, corolla, androecium and gynoecium.
3. The part of the flower that gives rise to the fruit is
(a) Sepals
(b) Petals
(c) Ovary
(d) Stamens
Solution
(c) Ovary
The ovary develops into ovules (seeds).
4. The part of the flower that gives rise to the seed is
(a) Ovary
(b) Placenta
(c) Ovule
(d) Pollen grain
Solution
(c) Ovule
It is the swollen area in the ovary that attaches the ovules to the wall of the ovary known as placenta.
5. The essential whorls of a flower are the
(a) Calyx and corolla
(b) Stamen and ovary
(c) Calyx and epicalyx
(d) Androecium and gynoecium
Solution
(d) Androecium and gynoecium
B. Very Short Answer Type
1. Match the parts in Column A with the flowers or parts of flower in Column B.
|
Column A |
Column B |
|
(a) Polyadelphous |
(i) Polypetalous |
|
(b) Pollen grains |
(ii) calyx, corolla |
|
(c) Free petals |
(iii) Nectar |
|
(d) Non-essential |
(iv) Bombax |
|
(e) Sweet fragrant fluid |
(v) Pollen sac |
Solution
Column A
|
Column A |
Column B |
|
(a) Polyadelphous |
(iv) Bombax |
|
(b) Pollen grains |
(v) Pollen sac |
|
(c) Free petals |
(i) Polypetalous |
|
(d) Non-essential |
(ii) calyx, corolla |
|
(e) Sweet fragrant fluid |
(iii) Nectar |
C. Short Answer Type
1. Explain the following terms:
(a) Incomplete flower
(b) Staminate flower
(c) Pistillate flower
(d) Bisexual flower
Solution
(a) Incomplete flower: If one or more sets of floral structures are missing, the flower is called incomplete flower.
Example: 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.
Example: 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.
Example: Date palm.
(d) Bisexual flower: A flower which contains both stamens and carpels is called bisexual or hermaphrodite flower.
Example: Hibiscus.
2. Distinguish between the following pairs:
(a) Flower and inflorescence
(b) Petals and petaloid sepals
(c) Polyandrous and Polyadephous androecium
Solution
(a) Difference between 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) Difference between 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) Difference between Polyandrous and Polyadephous androecium
|
Polyandrous |
Polyadephous androecium |
|
The filaments of the stamens are free. |
The filaments of the stamens are united in multiple groups. |
3. Where are the following structures/parts located and what are their functions?
(a) Placenta
(b) Thalamus
(c) Anther
(d) Stigma
Solution
(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
4. Why are the following describes as stated:
(a) The androecium of pea flower is diadelphous
(b) Ray florets of sunflower as neuters
(c) Salvia sepals as petaloid
Solution
(a) It is because the filaments of anthers are united and clubbed together in 2 bundles. Nine out of ten stamens in a pea plant form a stamina tube. The tenth is free.
(b) It is because both the female and male reproductive structures are absent.
(c) Sepals of the salvia are petaloid as 3 sepals are red in color and united as petals. Therefore, they are not differentiated from the petals.
D. Long Answer Type
1. Name the different types of androecium found in flowers.
Solution
The different types of androecium found in flowers are:
(i) Polyandrous: When the stamens of a flower are free, the condition is called polyandrous.
(ii) Monadelphous: When the filaments of anthers in a flower are fused into one group, the condition is called monadelphous.
(iii) Diadelphous: When the filaments of anthers in a flower are fused into two groups, the condition is called diadelphous.
(iv) Polyadelphous: When the filaments of anthem in a flower are fused into more than two groups, the condition is called polyadelphous.
2. Name the type of androecium found in
(a) China rose
(b) Bombax
(c) Pea
Solution
(a) China rose: Monadelphous
(b) Bombax: Polyadelphous
(c) Pea: Diadelphous
E Structured/Application/Skill Type
1. The figure given alongside represents generalized arrangement of the different parts of a bisexual flower. Name the parts numbered 1-10.
Solution
1: Anther
2: Filament
3: Ovule
4: Placenta
5: Stigma
6: Style
7: Ovary
8: Petal
9: Sepal
10: Receptacle/Thalamus
2. Given alongside are two figures (A & B) of a certain part of a flower. Study the figures carefully and answer the following questions:
(b) Are the contents of the pollen sacs in B male or female?
(c) Can you state how the contents of the pollen sacs would come out?
Solution
(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.
3. What are bracts? State their functions.
Solution
When a flower arises in the axill 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.
4. Explain the terms Monadelphous, Diadelphous and Polyadelphous. In each case name a flower possessing such an androecium.
Solution
|
Condition of androeelum |
Explanation |
Example of flower |
|
Monadelphous |
Filaments of the anthem in a flower are fused into one group |
Hibiscus |
|
Diadelphous |
Filaments of the anthem in a flower are fused into two groups |
Pea |
|
Polyadelphous |
Filaments of the anthem in a flower are fused into more than two groups |
Bombax |