Morphology of Flowering Plants: Important Questions

All flowering plants, also known as angiosperms, have roots, stem, leaves, flowers and fruits, but their external structures vary from one to the other. The outer visible structures of a plant is called morphology of a plant. The section of a flowering plant below-ground is called the root system, while the portion above is called the shoot system. The root system is responsible for anchorage and absorption of minerals and water for plant growth from the soil.

The shoot system is responsible for transport of minerals and water throughout the plant, synthesis of food, transpiration, and other processes that sustain a plant’s life. All the important questions related to morphology of plants are discussed below in detail: 

Read More: Morphology of Flowering Plants

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Very Short Answer Questions [1 Mark Questions]

Ques. What is meant by the modification of a root?

Ans. The main function of a root is to absorb water and minerals from the soil. The modification of root is associated with structural and morphological modification in order to perform other functions in plant such as storage of food and providing structural support.

Ques. Are all underground parts of a plant roots?

Ans. No, various parts of plant, like stem, leaves and fruits are modified to act as underground structures which can perform functions other than those of roots.

Ques. Why do the tips of modified stems in potatoes become swollen?

Ans. Modified stem in potato is underground development and the presence of swollen structures are due to accumulation of food gets accumulated to form tubers.

Ques. Which parts of a peanut plant grow underground?

Ans. The fruits and seeds of a peanut are formed in the soil.

Ques. What is phyllotaxy?

Ans. Phyllotaxy is the arrangement of leaves on a stem.

Ques. Define the term aestivation.

Ans. The term aestivation is used for arrangement of floral bud in plants. In this, the node in which the petals of a plant are arranged in a floral bud.

Ques. Define the term placentation.

Ans. Placentation is the arrangement of ovules within the ovary of a flower.

Also Read: Stomata

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Short Answer Questions [2 Marks Questions]

Ques. Which parts of ginger and banana are underground other than the roots?

Ans. The stems of ginger and banana are modified to be underground where they help in the storage of food. They’re called rhizomes.

Ques. What is an actinomorphic? Give an example.

Ans. An actinomorphic flower is a flower that can be divided into two radial halves by any radial plane passing through its center. An example is the mustard flower.

Ques. What is a zygomorphic? Give an example.

Ans. Zygomorphic flowers can be divided into two similar halves by a single vertical plane. An example is peas.

Ques. What is a superior ovary? Give an example.

Ans. In flowers of superior ovary, the gynoecium is present at the topmost position, and other floral parts are arranged below it. This arrangement is termed hypogynous. An example is eggplant or brinjal.

Ques. What is a perigynous flower? Give an example.

Ans. In a perigynous flower, the gynoecium is present in the center and the remaining floral parts are arranged at the rim of the thalamus at the same level. An example is stem.

Ques. What is epipetalous stamen?

Ans. Stamen is the male reproductive part of a flower, and epipetalous stamen are stamen that are attached to the petals.

Also Check: Difference of Carpel and Pistil

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Long Answer Questions [3 Marks Questions]

Ques. What is the type of root modification found in each of the following:

1. Banyan Tree
2. Turnip
3. Mangrove Tree

Ans. Follwing are the type of root modification in given plants: 

1. Banyan trees have adventitious roots that are pillar-like, and they come from the aerial part of the stem. These roots grow towards the ground and act as a pillar of support for the tree. They are called ‘prop roots.’
2. Turnip roots play a role in storing food for plants after photosynthesis.
3. The roots of mangrove trees help to absorb oxygen from the atmosphere. For this purpose, they grow vertically upwards from the soil.

Ques. Why is the flower a modified shoot?

Ans. During the flowering season of a plant, the apical meristem switches to a floral meristem. This causes the axis of the stem to get condensed, while the internodes lie beside each other. Several floral appendages arise from the nodes instead of leaves, which leads to the statement that the flower is a modified shoot.

Ques. What are some features of a fibrous root?

Ans. Following are some of the important feautures of fibrous root present in plants: 

• Fibroous roots have many minute hairlike roots forming a thick layer under the soil. These root systems are extremely efficient at water and mineral absorption, and plant stabilization.
• In monocots, the primary root that develops from the radicles of the seed is short-lived and is replaced by a large number of roots arising from the base of the stem.
• Fibrous Roots are normally found in wheat, among different other cereals.

Ques. What are some features of an adventitious root?

Ans. Following are some important features of adventitious roots: 

• Adventitious roots are formed from non-root tissues and can be made either naturally or in response to stressful conditions such as flooding, lack of nutrition, and wounding.
• It can be found in banyan, and monstera.

Ques. Cite two differences between apocarpous ovary and syncarpous ovary.

Ans. Here are some of the major differences between apocarpous and syncarpous ovary discussed below in a tabular form: 

Ques. What are the differences between pinnately compound leaf and palmately compound leaf? Give examples of each.

Ans. The major differences between pinnately compound leaf and palmately compound leaf are listed below in tabular form: 

Ques. Describe the different types of phyllotaxy with suitable examples.

Ans. There are 3 types of phyllotaxy:

• Alternate phyllotaxy: In this phyllotaxy, a single leaf arises from the node of a branch. Examples are: Sunflower, mustard, and peepal.
• Opposite phyllotaxy: Opposite phyllotaxy is when two leaves arise from the node of a branch and extend out in opposite directions. Examples are: guava and jamun tree.
• Whorled phyllotaxy: Whorled phyllotaxy is when 3 or more leaves arise from the node of a branch. An example is alstonia.

Types of Phyllotaxy

Ques. Differentiate between racemose inflorescence and cymose inflorescence.

Ans. The complete arrangement of stems, stalks, bracts, and flowers on a flower head is called Inflorescence. Some important differences between racemose and cymose inflorescence are as follows: 

Very Long Answer Questions [5 Marks Questions]

Ques. Describe the modifications of various stems with suitable examples.

Ans. Here are some of the important modifications of various stems listed below: 

1. Storage stems, also known as underground stems: Examples of storage stems are rhizomes, corms, and tubers. In ginger and banana, the underground stem is called rhizomes. In arvi, the underground stem is called corm. In potatoes, the underground stem is called tuber. All of these have been modified to store food.
2. Supportive stems: Examples of supportive stems are tendrils. They are thin, slender, and coil spirally. They can be found in various members of the family cucurbitaceae, including cucumber and melons. Tendrils help attach the plant to nearby structures for support.
3. Protective stems: Examples of protective stems are thorns, and they can be found in bougainvillea and citrus plants. Thorns are sharp, pointed structures that protect the plant from herbivores.
4. Photosynthetic stems: Opuntia is a photosynthetic stem. It is green in appearance, and carries out photosynthesis in the absence of green leaves.

Also Check: Double Fertilization

Ques. Highlight the different placentations found in flowering plants.

Ans. Placentation is the arrangement of ovules within the ovary, and there are 5 types:

• Marginal placentation: This is when ovules in the ovary develop on two separate rows, as found in peas.
• Parietal placentation: This is when ovules develop on the inner walls of the ovary.
• Axile placentation: This is when the placenta is axial and ovules are attached to it, as found in china rose, lemon, and tomato.
• Basal placentation: This is when the ovary in which the placenta develops from its base has a single ovule attached to the base, as found in marigold and sunflower.
• Free central placentation: This is when the ovule develops on the central axis while the septa are absent, as found in primrose.

Ques. Describe a flower and its several parts.

Ans. A flower is a reproductive unit of flowering plants.

• It carries out sexual reproduction and acts as a modified stem with a condensed axis. 
• A flower has 4 different parts: calyx, corolla, androecium, and gynoecium. 
• A unisexual flower contains either androecium or gynoecium, and a bisexual flower typically contains both androecium and gynoecium.
• Corolla and calyx are generally distinct but may be fused into forming a structure called a perinath.
• The flower that contains all 4 of the floral parts is called a complete flower.

Structure of a Flower

The parts:

• Calyx: This forms the outermost whorl of a flower containing sepals. It is a green leafy structure that covers and protects the flower during its bud stage.
• Corolla: This is a layer that lies inside the calyx. It contains beautifully coloured petals, which help to attract insects for pollination.
• Androecium or stamen: This is the male reproductive part of a flower and consists of two parts: the filament and bilobed anther. The bilobed anther holds pollen grains which produce male gametes for reproduction.
• Gynoecium: This is the female reproductive part of a flower. It consists of an ovary which is connected to the stigma by a long tube called style. Ovary bears numerous ovules attached to the placenta.