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Chapter 4

The Flower

Class 9 - Concise Biology Selina


Multiple Choice Type

Question 1

Bougainvillea flower is an example of

  1. incomplete flower
  2. having a large nectary
  3. water pollination
  4. large colourful bracts ✓

Question 2

A flower is said to be complete when:

  1. It has the corolla and calyx
  2. It has the corolla and gynoecium
  3. It has the androecium and gynoecium
  4. It has all the four whorls ✓

Question 3

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

  1. Sepals
  2. Petals
  3. Ovary ✓
  4. Stamens

Question 4

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

  1. Ovary
  2. Placenta
  3. Ovule ✓
  4. Pollen grain

Question 5

The essential whorls of the flower are the

  1. Calyx and Corolla
  2. Stamen and ovary
  3. Calyx and epicalyx
  4. Androecium and gynoecium ✓

Very Short Answer Type

Question 1

Match the parts in column A with the flowers or parts of flower in column B.

Column AColumn B
PolyadelphousPolypetalous
Pollen grainsCalyx, corolla
Free petalsNectar
Non-essentialBombax
Sweet fragrant fluidPollen sac

Answer

Column AColumn B
PolyadelphousBombax
Pollen grainsPollen Sac
Free petalsPolypetalous
Non-essentialCalyx, corolla
Sweet fragrant fluidNectar

Short Answer Type

Question 1

Explain the following terms:

  1. Incomplete flower
  2. Staminate flower
  3. Pistillate flower
  4. Bisexual flower

Answer

  1. Incomplete flower — A flower is said to be an incomplete flower if one or more sets of floral whorls are missing. E.g. American Elm.

  2. Staminate flower — A unisexual flower which contains only the stamens is called the male or staminate flower. E.g. Eastern Cottonwood.

  3. Pistillate flower — A flower which contains only the carpels is called the female or pistillate flower. E.g. Date Palm.

  4. Bisexual flower — A flower which contains both stamens and carpels is called a bisexual or hermaphrodite flower. E.g. Rose.

Question 2

Distinguish between the following pairs:

  1. Flower and inflorescence
  2. Petals and petaloid sepals
  3. Polyandraus and Polyadephous androecium

Answer

  1. Flower and inflorescence
FlowerInflorescence
Flower is a specialized shoot in which internodes are shortened and leaves are modified into floral structure.It refers to the mode of arrangement of flowers on the axis of a plant.
  1. Petals and Petaloid Sepals
PetalsPetaloid Sepals
Non-essential parts of the flower which help in protection of reproductive parts or make the flower attractive for pollination.Sometimes sepals are undifferentiated. These taken together are called perianth. When perianth is non-green, it is described as a petaloid.
  1. Polyandraus and Polyadephous Androecium
PolyandrausPolyadephous Androecium
The filaments of the stamens are free.The filaments of the stamens are united in the multiple groups.

Question 3

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

  1. Placenta
  2. Thalamus
  3. Anther
  4. Stigma

Answer

  1. Placenta:
    Location — Cushion or swollen region in the ovary.
    Function — Gives origin to ovules.

  2. Thalamus:
    Location — Tip of the flower stalk .
    Function — Bears all the parts of the flower.

  3. Anther:
    Location — Part of the stamen.
    Function — Produces male gametes or pollen grains.

  4. Stigma:
    Location — Terminal knob like part.
    Function — Serves as the landing place for pollen grains during pollination.

Question 4

Why are the following described as stated:

  1. The androecium of pea flower is diadelphous.
  2. Ray florets of sunflower as neuters
  3. Salvia sepals as petaloid

Answer

  1. It is because the filaments of anthers are united in two bundles. Nine out of ten stamens in a pea plant form a staminal tube. The tenth is free.
  2. Ray florets of sunflower are described as neuters because both male and female reproductive structures are lacking.
  3. 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.

Long Answer Type

Question 1

Name the different types of androecium found in flowers.

Answer

The different types of androecium found in flowers are-

  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 anther in a flower are fused into more than two groups the condition is called polyadelphous.

Question 2

Name the type of the androecium found in

  1. China rose
  2. Bombax
  3. Pea

Answer

  1. China rose — The type of androecium found is Monadelphous.
  2. Bombax — The type of androecium found is Polyadelphous.
  3. Pea — The type of androecium found is Diadelphous.

Structure / Application / Skill Type

Question 1

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

Name the parts numbered 1-10 of a bisexual flower. The Flower, Concise Biology ICSE Class 9.

Answer

The parts labelled from 1 to 10 are as follows:

  1. Anther
  2. Filament
  3. Ovule
  4. Placenta
  5. Stigma
  6. Style
  7. Ovary
  8. Petal
  9. Sepal
  10. Receptacle / Thalamus

Question 2

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

Study the figures of certain part of flower and answer the following questions. The Flower, Concise Biology ICSE Class 9.
  1. Which major organ of a flower does the figure A represent? What is the collective term for this organ?
  2. Are the contents of the pollen sacs in B, male or female?
  3. Can you state how the contents of the pollen sacs would come out?

Answer

  1. Figure A represents stamen. Stamens collectively form Androecium.
  2. Contents of the pollen sacs in B, are male gametes.
  3. The contents of the pollen sacs would come out through agents like air, wind, insects leading to pollination in flowers.

Question 3

What are bracts? State their function.

Answer

When a flower arises in the axil of a leaf like structure, this structure is known as bract. It may be green like leaves or at times they are coloured structures, they are often mistaken for petals. This helps to attract insects for pollination.

Question 4

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

Answer

  1. Monadelphous — Filaments of the anthem in a flower are fused into one group. For example, Hibiscus

  2. Diadelphous — Filaments of the anthem in a flower are fused into two groups. For example, Pea

  3. Polyadelphous — Filaments of the anthem in a flower are fused into more than two groups. For example, Bombax.

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