NCERT Solutions for Class 11 Biology Chapter 5 - Morphology of Flowering Plants

Download PDF Class 11 Biology Chapter 5 Solutions

Chapter 5 becomes easier to study when students get simple and clear solutions. Different parts of a plant, like roots, stems, leaves, flowers, and fruits are included. Students can download the PDF of the Morphology of Flowering Plants from the link given below. They can use NCERT Solutions for Class 11 Biology to revise quickly and learn better.

Download PDF

Get Detailed Class 11 Biology Chapter 5 Solutions (Exercise Questions)

The detailed explanations of all the questions given in the textbook are given below. All answers are prepared in simple language by the subject experts. Practicing these Class 11 Biology Chapter 5 question answers allows students to improve their understanding.

Question 1 . What is meant by the modification of the root? What type of modification of root is found in the:

(a) Banyan tree

(b) Turnip

(c) Mangrove trees

Answer:

Roots are the underground water and mineral-absorbing structures of plants. Besides the role of water and mineral absorption, the roots of certain plants tend to modify to serve various other purposes, like storage, nitrogen fixation, aeration support, etc. Such structures are referred to as root modifications.

The modification of the root found in

(a) Banyan tree- The roots of a banyan tree are modified to offer support to the plant. The Banyan tree has pillar-like adventitious roots, which emerge from the aerial stem part. The roots grow downward and offer support to the plant. Such roots are referred to as prop roots.

(b) Turnip- The root of the turnip is referred to as a napiform root and aids in the storage of food.

(c) Mangrove tree- These have roots that are modified for the uptake of oxygen by extending vertically upwards from the ground. These roots are referred to as pneumatophores.

Question 2. Justify the following statements based on external features:

(i) Underground parts of a plant are not always roots.

Answer:

The root of a plant is typically beneath the soil, and the stem is above ground. The root does not have to be alone as part of the plant located in the soil, though. Stems, in certain unique circumstances, also reside in the soil. Ginger and banana are some examples of such plants with stems located below ground and enlarged for food storage. They are known as rhizomes. Likewise, the corm is a stem that grows underground in Colocasia. Likewise, in peanuts, the flower, having been fertilised, gets buried in the ground by developing a flower stalk. Therefore, with this knowledge, it can be understood that the underground parts of a plant are not always roots.

Question 3. Justify the following statements based on external features:

(ii) A flower is a modified shoot.

Answer:

After a certain period of growth, the apical meristem of a stem gives rise to the floral meristem. During the formation of the floral meristem, the axis of the stem gets condensed, and the internodes lie near each other. Various floral appendages arise from the node. A flower can be said to be a modified shoot because of the presence of nodes and internodes.

Question 4. How is a pinnately compound leaf different from a palmately compound leaf?

Answer:

Question 5. Explain with suitable examples the different types of phyllotaxy.

Answer:

The pattern of arrangement of leaves on the stem or branch is called Phyllotaxy. There are three types of phyllotaxy found in plants.

1. Alternate phyllotaxy- On a branch, a single leaf arises at each node. E.g., China rose

2. Opposite phyllotaxy- At one node, two leaves arise, opposite to each other. E.g., guava plant

3. Whorled phyllotaxy- More than two leaves arise at a node and form a whorl in whorled phyllotaxy. E.g., Alstonia

Question 6. Define the following terms:

(a) aestivation

Answer:

Aestivation- The mode of arrangement of sepals or petals in the floral bud, concerning the other members of the same whorl, is called aestivation. Aestivation in plants can be valvate, Wisted, imbricate, and vexillary.

Question 7. Define the following terms:

(b) placentation

Answer:

Placentation- The arrangement of ovules within the ovary is called placentation. There are five types of placentation found in plants, including marginal, basal, parietal, axile, and free central placentation.

Question 8. Define the following terms:

(c) actinomorphic

Answer:

Actinomorphic- The flowers that can be divided into two radial halves by any radial plane passing through their centre are called actinomorphic flowers. E.g.,chilly and mustard.

Question 9. Define the following terms:

(d) zygomorphic

Answer:

Zygomorphic- The flowers that can be divided into two similar halves by a single vertical plane only are known as zygomorphic flowers. E.g., peas and beans.

Question 10. Define the following terms:

(e) superior ovary

Answer:

Superior ovary- When the gynoecium is present at the highest position, while other floral parts are arranged below it, the ovary is said to be a superior ovary. A flower with this arrangement is described as hypogynous. Examples include brinjal and mustard.

Question 11. Define the following terms:

(f) perigynous flower

Answer:

Perigynous flower- When the gynoecium is present in the centre while the rest of the floral parts are present at the rim of the thalamus at the same level as the gynoecium, the flower is called a perigynous flower. E.g., plum and rose.

Question 12. Define the following terms:

(g) epipetalous same

Answer:

Epipetalous stamen- The stamen which remains attached to the petals is called epipetalous stamen E.g., brinjal

Question 13. Differentiate between

(a) Racemose and cymose inflorescence

Answer:

Question 14. Differentiate between

(b) Fibrous root and adventitious root

Answer:

Question 15. Differentiate between

(c) Apocarpous and syncarpous ovary

Answer:

Question 16. Draw the labelled diagram of the following:

(i) gram seed

Answer:

Structure of gram seed-

Question 17. Draw the labelled diagram of the following:

(ii). V.S. of maize seed

Answer:

V.S. of maize seed

Question 18. Describe modifications of the stem with suitable examples.

Answer:

The most important kinds of stem modifications are:

1. Rhizome- It is a fleshy, non-green underground stem with clear nodes and internodes. The nodes have dry-scale leaves with axillary buds. Adventitious roots develop from the lower side. e.g., Alocasia, Dryopteris, Banana, Ginger, turmeric, Canna, etc.

2. Bulb- It is a subterranean pyriform to globular structure with a diminutive convex or small conical disc-shaped stem and several fleshy scales covering a terminal bud. e.g., Lily, onion, etc.

3. Corm- It is a short and thickened form of rhizome that grows vertically. It is more or less globular with a broad, flat base. Adventitious roots develop either from its base or throughout the body. Examples- Colocasia, Amorphophallus.

4. Tuber- It is a swollen tip of an underground stem. It has several small depressions referred to as eyes. These eyes are nodes. Adventitious roots are generally missing, e.g., Potato.

5. Runner- These are narrow, green, above-ground, special horizontal or prostrate branches that form at the bases of erect shoots known as crowns. E.g., Centella, Oxalis, doob grass, etc.

6. Stolon- These are long, creeping horizontal runners that may jump over small obstacles. The apex of the stolon usually develops above ground level. E.g., Jasmine, peppermint, wild strawberry, etc.

7. Offset- They are one internode long, little runners that occur in rosette plants at ground level. E.g., Pistia, Eichhornia, etc.

8. Stem-tendrils- These are thread-like, sensitive organs that curl around support and assist the plant in climbing. E.g. grapevine.

9. Stem thorns- These are tough, rigid, and pointed structures that defend the plants. E.g., Citrus, Bougainvillea, Duranta, etc.

10. Phylloclade- They are flattened or cylindrical green stems of indefinite growth that have assumed the role of photosynthesis. The development of phylloclades enables the plants to thrive in arid environments. e.g. Opuntia, Casuarina etc.

11. Cladode- These are green, short-stemmed axes that have replaced the function of photosynthesis by the leaves. The leaves are reduced to spines or scales. E.g. Ruscus.

Question 19. Describe the various types of placentations found in flowering plants

Answer:

Placentation is the positioning of ovules in the ovary of a flower. Plants may have 5 different types of placentation. They are as follows:

1. Marginal placentation: The placenta develops as a ridge along the ventral suture of the ovary, and the ovules mature on two distinct rows in marginal placentation, e.g., peas.

2. Parietal placentation: If the ovules grow against the inner wall of the ovary, the ovary will be called to have parietal placentation.

3. Axile placentation: Here, the placenta will be axial and will have attached to it the ovules, e.g. China rose, lemon, and tomato.

4. Basal placentation: In basal placentation, the placenta grows from its base, and there is one ovule attached to the base. It occurs in marigolds and sunflowers.

5. Free central placentation: The septa are missing in free central placentation as the ovules are present on the central axis. Dianthus and primrose are the plants exhibiting free central placentation.

Question 20. What is a flower? Describe the parts of a typical angiosperm flower.

Answer:

Flower is the reproductive organ of angiospermic plants for sexual purposes of reproduction. A general flower consists of four whorls on the swollen tip of the stalk or pedicle known as the thalamus. They include Calyx, Corolla, Androecium, and Gynoecium.

1. Calyx- It is the outermost whorl of a flower. It is composed of units known as sepals. It is usually green in colour and protective in function.

2. Corolla- It is the whorl that occurs inner to the Corolla. It comprises petals. The petals are vividly coloured to entice the insects.

3. Androecium- It is the whorl occurring beside the corolla. The androecium contains primarily stamens, which are the male reproductive parts of a flower. A stamen has two components, i.e., an anther and a filament. The anther is a bilobed body having a stalk referred to as a filament. Within the anther, the pollen grains develop.

4. Gynoecium- The innermost whorl of the flower is known as the gynoecium. It comprises pistils. A pistil has three constituents: stigma, style, and ovary. Pistils are the female reproductive units of a flower.

Question 21. How do the various leaf modifications help plants?

Answer:

The leaf is a green, flat, and lateral outgrowth that is supported on the node of a stem or branches of a stem and is specialised to carry out photosynthesis. Besides photosynthesis, leaves usually get modified to carry out various other functions as well. Some of the leaf modifications in plants that benefit the plants are as follows:

1. Tendrils- Plant leaves can transform into tendrils that assist the plants in climbing

2. Spines- These are stiff and hard structures that function as organs of defence. e.g. cactus

3. Phyllode- Leaves of certain plants are ephemeral and are replaced soon by flattened, green organs known as phyllodes. These develop from the petiole of the leaves and are concerned with synthesising the food.

4. Pitcher- Pitcher plant leaves are modified in the form of pitcher-like organs. These possess digestive juices and assist in catching and digesting insects.

Question 22. Define the term inflorescence. Explain the basis for the different types of inflorescence in flowering plants.

Answer:

The arrangement of flowers on the floral axis is termed inflorescence. There can be two types of inflorescence, i.e. racemose and cymose, based on whether the floral axis continues to grow or ends in a flower. In racemose inflorescence, the floral axis continues to grow and bear flowers, whereas in cymose inflorescence, the floral axis stops growing and terminates in a flower.

Question 23. Write the floral formula of an actinomorphic, bisexual, hypogynous flower with five united sepals, five free petals, five free stamens, and two united carpels with a superior ovary and axile placentation.

Answer:

The floral formula of an actinomorphic, bisexual, hypogynous flower with five united sepals, five free petals, five free stamens, and two united carpels with the superior ovary and axile placentation is as follows:

Question 24. Describe the arrangement of floral members about their insertion on the thalamus.

Answer:

There may be three kinds of floral member arrangements around their insertion on the thalamus. These are:

1. Hypogynous – The Ovary is at the topmost position, and the remaining parts are at a lower level than the ovary. The ovary in such flowers is known as superior. E.g., Brinjal, mustard, and China rose. The flowers with such an arrangement are termed hypogynous flowers.

2. Perigynous -In this type, the gynoecium is placed in the centre, and other structures are on the edge at the same level. This type of ovary is referred to as half-inferior, and flowers as perigynous.

3. Epigynous- Here, the ovary lies below all the other structures. The ovary here is referred to as inferior, whereas the flower is referred to as an epigynous flower.

NCERT Solutions for Class 11: Subject-wise

• NCERT Solutions for Class 11 Maths
• NCERT Solutions for Class 11 Chemistry
• NCERT Solutions for Class 11 Physics

Approach to Solve Class 11 Biology Chapter 5 Question Answers

The Morphology of Flowering Plants includes many concept-based questions. Given below are some effective ways to answer the questions effectively.

• Students first need to understand the meaning of terms like root, stem, leaf, inflorescence, flower, fruit, and seed.

• After that, making quick notes with examples is important to revise easily. Students can take help from the Morphology of Flowering Plants Class 11 NCERT Solutions.

• Many questions in the exam are directly taken from the NCERT textbook. That's why it is important to read and understand each line thoroughly.

• Labelled diagrams are very important. Different types of roots, leaves, and floral structures need to be practised. All these are included in the NCERT Solutions for Class 11 Biology Chapter 5 PDF.

• Try to solve previous-year questions and in-text exercises to get familiar with the pattern. To gain confidence in the upcoming exams, refer to the NCERT Solutions for Class 11.

Also, check the NCERT Books and the NCERT Syllabus here :

• NCERT Books Class 11 Biology

• NCERT Syllabus Class 11 Biology

• NCERT Books Class 11

• NCERT Syllabus Class 11

Important Question from Class 11 Biology Chapter 5 Solutions

Here is an important question from this chapter, along with the solution. Solving different questions allows students to improve their problem-solving skills. For more such questions, they can refer to the Morphology of Flowering Plants Class 11 NCERT Solutions.

Question 1: Endosperm, a product of double fertilisation in angiosperms, is absent in the seeds of

A. Coconut

B. Maize

C. Orchids

D. Castor

Answer:

The endosperm may be completely consumed by the developing embryo (e.g., pea, groundnut, beans) before seed maturation. Such seeds are called non-endospermic or exalbuminous. It may persist in the mature seed (e.g. castor and coconut) and be used up during seed germination. Such seeds are called endospermic or albuminous.

The embryo in the orchid plant absorbs the endosperm during growth.

Hence, the answer is option (C) Orchids

What extra should students study beyond the NCERT for NEET?

For the NEET exam, NCERT is very helpful, but learning a few extra things can give students extra help. Focus on important terms and diagrams to improve the understanding. Students can also refer to the Morphology of Flowering Plants Class 11 NCERT Solutions to revise concepts quickly.

Chapter-Wise NCERT Solutions for Class 11 Biology

Below are the Chapter-wise solutions: