SELINA Solutions for Class 9 Biology Chapter 4 - The Flower

  - Choose Chapter -  Chapter 1 - Introducing Biology  Chapter 2 - Cell: The Unit Of Life  Chapter 3 - Tissues: Plant And Animal Tissues  Chapter 4 - The Flower  Chapter 5 - Pollination and Fertilization  Chapter 6 - Seeds: Structure and Germination  Chapter 7 - Respiration in Plants  Chapter 8 - Five Kingdom Classification  Chapter 9 - Economic Importance Of Bacteria And Fungi  Chapter 10 - Nutrition  Chapter 11 - Digestive System  Chapter 12 - Movement And Locomotion  Chapter 13 - Skin - The Jack Of All Trades  Chapter 14 - The Respiratory System  Chapter 15 - Hygiene - A Key To Healthy Life  Chapter 16 - Diseases: Cause And Control  Chapter 17 - Aids To Health  Chapter 18 - Health Organisations  Chapter 19 - Waste Generation and Management 

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Ex. 1

Chapter 4 - The Flower Exercise Ex. 1

Question A

Multiple Choice Questions:

1. Bougainvillea flower is an example of

(a) incomplete flower

(b) having a large nectary

(c) water pollination

(d) large colourful bracts

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

 3. The part of the flower that gives rise to the fruit is

(a) Sepals

(b) Petals

(c) Ovary

(d) Stamens

4. The part of the flower that gives rise to the seed is

(a) Ovary

(b) Placenta

(c) Ovule

(d) Pollen grain

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 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

Question B.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 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

 

Question C.1

Explain the following terms:

(a) Incomplete flower

(b) Staminate flower

(c) Pistillate flower

(d) Bisexual flower

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.

Question C.2

Distinguish between the following pairs:

(a) Flower and inflorescence

(b) Petals and petaloid sepals

(c) Polyandrous and polyadelphous androecium

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.

Question C.3

Where the following structures/parts located and what are their functions?

(a) Placenta

(b) Thalamus

(c) Anther

(d) Stigma

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

Question E.1

The figure given alongside represents generalized arrangement of the different parts of a bisexual flower. Name the parts numbered 1-10.

 

 

Solution E.1

1: Anther; 2: Filament: 3: Ovule: 4: Placenta; 5: Stigma;

6: Style; 7: Ovary; 8: Petal; 9: Sepal; 10: Receptacle/Thalamus

Question E.2

Given below are two figures (A and B) of a certain part of a flower. Study the figures carefully and answer the following questions:

 

 

(a) Which major organ of a flower does the figure A represent? What is the collective term for this organ ?

(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 E.2

(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.

Question E. 3

What are bracts? State their function.

Solution E. 3

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.

Question E. 4

Explain the terms Monadelphous, Diadelphous and Polyadelphous. In each case name a flower possessing such an androecium.

Solution E. 4

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

Question D.1

Name the different types of androecium found in flowers.

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. 

Question D.2

Name the type of androecium found in

(a) China rose

(b) Bombax

(c) Pea 

Solution D.2

(a) China rose: Monadelphous

(b) Bombax: Polyadelphous

(c) Pea: Diadelphous