NCERT Exemplar Class 11 Biology Solutions Chapter 5 Morphology of Flowering Plants

Multiple Choice Questions:

Question:1

Rearrange the following zones as seen in the root in vertical section and
choose the correct option.
A. Root hair zone
B. Zone of meristems
C. Rootcap zone
D. Zone of maturation
E. Zone of elongation
Options:
(a) C, B, E, A, D
(b) A, B, C, D, E
(c) D, E, A, C, B
(d) E, D, C, B, A

Answer:

Question:2

In an inflorescence where flowers are borne laterally in an acropetal succession, the position of the youngest floral bud shall be
(a) Proximal
(b) Intercalary
(c) Distal
(d) Any where

Answer:

Question:3

The mature seeds of plants such as gram and peas, possess no endosperm,because
(a) Endosperm gets used up by the developing embryo during seed development
(b) There is no double fertilization in them
(c) Endosperm is not formed in them
(d)These plants are not angiosperms

Answer:

Question:4

Roots developed from parts of the plant other than radicle are called
(a) Taproots
(b) Adventitious roots
(c) Fibrous roots
(d) Nodular roots

Answer:

Question:5

Venation is a term used to describe the pattern of arrangement of
(a) Veins and veinlets in a lamina
(b) Flower in inflorescence
(c) Floral organs
(d) All of them

Answer:

Question:6

Endosperm, a product of double fertilization in angiosperms is absent in the seeds of
(a) Coconut
(b) Maize
(c) Orchids
(d) Castor

Answer:

Question:7

Many pulses of daily use belong to one of the families below (tick the correct answer)
(a) Solanaceae
(b) Poceae
(c) Liliaceae
(d) Fabaceae

Answer:

Question:8

The placenta is attached to the developing seed near the
(a) Hilum
(b) Testa
(c) Micropyle
(d) Chalaza

Answer:

Question:9

Which of the following plants is used to extract the blue dye?
(a) Trifolium
(b) Lupin
(c) Indigofera
(d) Cassia

Answer:

Question:10

Match the following and choose the correct option

Options:

a. A-i, B-ii, C-iii, D-iv

b. A-ii, B-i, C-iv, D-iii

c. A-iv, B-ii, C-i, D-iii

d. A-ii, B-iv, C-i, D-iii

Very Short Answer Type Questions:

Question:1

Roots obtain oxygen from air in the soil for respiration. In the absence or deficiency of O₂, root growth is restricted or completely stopped. How do the plants growing in marshlands or swamps obtain their O₂ required for root respiration?

Answer:

Question:2

Write floral formula for a flower which, is bisexual; actinomorphic; sepals five, twisted aestivation, petals five; valvate aestivation; stamens six; ovary tricarpellary, syncarpous, superior, trilocular with axile placentation.

Answer:

Question:3

In Opuntia the stem is modified into a flattened green structure to perform the function of leaves (i.e., photosynthesis). Cite some other examples of modifications of plant parts for the purpose of photosynthesis.

Answer:

Question:4

In swampy areas like the Sunderbans in West Bengal, plants bear a special kind of roots called _____.

Answer:

Question:5

In aquatic plants like Pistia and Eichhornia, leaves and roots are found near _____.

Answer:

Question:6

Reticulate and parallel venation are characteristic of _____ and _____ respectively.

Answer:

Question:7

Which parts in ginger and onion are edible?

Answer:

Question:8

In the epigynous flower, the ovary is situated below the _____.

Answer:

Question:9

Add the missing floral organs of the given floral formula of Fabaceae.

Answer:

Question:10

Name the body part modified for food storage in the following

(a) Carrot

(b) Colocasia

(c) Sweet potato

(d) Asparagus

(e) Radish

(f) Potato

(g) Dahlia

(h) Turmeric

(i) Gladiolus

(j) Ginger

(k) Portulaca

Answer:

Short Answers Type Questions:

Question:1

Give two examples of roots that develop from different parts of the angiospermic plant other than the radicle.Answer:

• Prop Roots in Banyan: The roots of a banyan tree is an example for prop roots. These prop roots deeply penetrate the soil and help the tree to maintain the balance and support itself.
• Stilt Roots in Maize: The roots in maize plants are an example for stilt roots.These roots enter the ground and are developed from the nodes just above the ground; they provide extra support to the maize plant.

Question:2

The essential functions of roots are anchorage and absorption of water and minerals in the terrestrial plant. What functions are associated with the roots of aquatic plants? How are the roots of aquatic plants and terrestrial plants different?

Answer:

Ans. As known by all, the basic function of roots is that of anchorage and absorption of water and minerals. Availability of water is not an issue for aquatic plants. That is why the roots are not properly grown in most of the aquatic plants. In these free-floating plants, the roots are very few in number and are in a structure of fine hairs. In the plants that are submerged, roots play the important role of anchorage.

Question:3

Draw diagrams of a typical monocot and dicot leave to show their venation pattern.

Answer:

Question:4

A typical angiosperm flower consists of four floral parts. Give the names of the floral parts and their arrangements sequentially.

Answer:

Ans. The arrangement of four floral parts is as follows; starting from the periphery of the flower: Calyx, Corolla, Androecium And Gynoecium.
Calyx is the part of the flower which is made up of green leaf-like sepals. Corolla is the part of the flower which is composed of colourful petals. Androecium is the part of the flower which consists of stamens (filament and anther). Gynoecium is the part of the flower which is composed of carpel (stima, style and ovary).

Question:5

Given below are a few floral formulae of some well-known plants. Draw floral diagrams from these formulae.

Answer:

Question:6

Reticulate venation is found in dicot leaves while in monocot leaves venation is of parallel type. Biology being a ‘Science of exceptions’, find out any exception to this generalization.

Answer:

Ans. These are some examples of exception to this generalisation:

• Parallel venation in dicot: Calophyllum, Corymbium
• Reticulate venation in monocot: Alocasia, Smilax

Question:7

You have heard about several insectivorous plants that feed on insects. Nepenthes or the pitcher plant is one such example, which usually grows in shallow water or in marshlands. What part of the plant is modified into a 'pitcher'? How does this modification help the plant for food even though it can photosynthesize like any other green plant?

Answer:

Ans. The leaves of the pitcher plant are modified into a pitcher. The pitcher is facilitated with a lid which is developed from the tip of the lamina. The anterior part of the petiole, which is coiled like a little tendril. It helps to keep the pitcher in a vertical position.

Question:8

Mango and coconut are ‘drupe’ type of fruits. In mango fleshy mesocarp is edible. What is the edible part of coconut? What does milk of tender coconut represent?

Answer:

Question:9

How can you differentiate between free central and axile placentation?

Answer:

Placentation: It is regarded as free central when the septa is absent, and the ovules are born on the central axis.

Placentation: It is regarded as axile when the placenta is axial, and the ovules are attached to the placenta in a multilocular ovary.

Question:10

Tendrils are found in the following plants. Identify whether they are stem tendrils or leaf tendrils.

a. Cucumber

b. Peas

c. Pumpkins

d. Grapevine

e. Watermelons

Answer:

a. Cucumber – Stem tendrils

b. Peas – Leaf tendrils

c. Pumpkins – stem tendrils

d. Grapevines – stem tendrils

e. Watermelons – stem tendrils

Question:11

Why is maize grain usually called as a fruit and not a seed?

Answer:

Question:12

Tendrils of grapevines are homologous to the tendril of pumpkins but are analogous to that of a pea. Justify the above statement.

Answer:

Tendrils of pumpkins are homologous to the tendrils of grapevines because both originate from the same part of the plan i.e., the stem despite having different functions. But the tendrils of grapevines and tendrils of pumpkins are analogous to that of a pea because the function of tendrils on pumpkin is to creep while in grapevines it is to climb.

Question:13

The rhizome of ginger is like the roots of other plants that grow underground. Despite this fact, ginger is a stem and not a root. Justify.

Answer:

The rhizome of ginger is like the roots of other plants that grow underground. Despite this fact, ginger is a stem and not a root. Because ginger is not a root but steam as it has internodes and nodes that roots do not possess.

Question:14

Differentiate between

a. Bract and Bracteole

b. Pulvinus and petiole

c. Pedicel and peduncle

d. Spike and spadix

e. Stamen and staminoid

f. Pollen and pollenium

Answer:

a. The bracteolate is found between the bract and flower while a bract is found towards the base of the pedicle.

b. Petiole is a subcylindrical stalk that connects the lamina with the leaf base while Pulvinus is a swollen leaf base which is found in leguminous plants.

c. The Peduncle is a stalk of the whole inflorescence while a pedicle is the stalk of a flower.

d. Spadix is covered by several large bracts known as spates while in spike sessile flowers are attached on an elongated peduncle.

e. Every stamen represents a male reproductive organ and androecium is composed of stamens. The staminode is a sterile stamen.

f. Polonium is defined as the group of pollen grains while a pollen is a male gametophyte of angiosperms.

Long Answer Type Questions:

Question:1

Distinguish between families Fabaceae, Solanaceae, Liliaceae on the basis of gynoecium characteristics (with figures), Also write economic importance of any one of the above family

Answer:

Gynoecium Characteristics	Solanaceae	Liliaceae	Fabaceae
Ovules	Many in each locular	Trilocular	Margin in two alternate rows
Placentation	Axile	2-many ovules in each locules	Marginal
Ovary	Superior bilocular(2-4locular in tomato)	Superior	Superior unilocular
Carpels	BicarpellarySyncarpous	Tricarpellarysyncarpous	Monocarpellary free, single
Style	Simple	Simple but may be united or separate	Bent, single

• Source of pulses
• Medicine
• Edible oil
• Dye
• Fibres
• Fodder
• Ornamental

Question:2

Describe various stem modifications associated with food storage,climbingand protection.

Answer:

• For storage of food, underground stems of ginger, turmeric, potato, and colocasia are modified. These stems also perform the function of organs of perennation that helps get over unfavourable growth conditions.
• Developed from axillary buds, stem tendrils are dare spirally coiled and are slender which helps the plants to climb. Some examples include grapevines, pumpkins, cucumber, and watermelon etc.

Question:3

Stolon, offset and rhizome are different forms of stem modifications. How can these modified forms of stem be distinguished from each other?

Answer:

Question:4

The mode of arrangement of sepals or petals in a floral bud is known as aestivation. Draw the various types of aestivation possible for a typical pentamerous flower.

Answer:

Question:5

The arrangements of ovules within the ovary is known as placentation. What does the term placenta refer to? Name and draw various types of placentations in the flower as seen in T.S. or V.S

Answer:

Question:6

Sunflower is not a flower. Explain.

Answer:

Ans. Sunflower is actually not a flower, but a bunch of flowers, altogether. Inflorescence is the term used for a bunch of exceedingly small flowers, for what it appears to be a single flower. These flowers are put on a receptacle in a special arrangement. This type of inflorescence of flowers is called capitulum.

These are some characteristics of capitulum: -

• There are many tiny, sessile florets present on the receptacle.
• The youngest florets are present at the center, while the oldest florets are at the periphery.
• The receptacle is flattened.
• There are two kinds of florets in a sunflower, viz. ray florets and disc florets.
• Ray florets are present on the rim of the receptacle. These are of yellow colour.
• Disc florets are present in the center. They are bisexual in nature and are actinomorphic.

Question:7

How do you distinguish between hypogeal germination and epigeal germination? What is the role of cotyledon (s) and the endosperm in the germination of seeds?

Answer:

Question:8

Seeds of some plants germinate immediately after shedding from the plants while in other plants they require a period of rest before germination. The latter phenomenon is called dormancy. Give the reasons for seed dormancy and some methods to break it.

Answer:

Reasons for seed dormancy:

The seed coat is hard, and the impermeable layers of the seeds prevent uptake of water, this inhibits growth and delays the process of germination. In some cases, the seeds have undeveloped embryos which is the reason for the delay in germination.

Methods to break seed dormancy:
Seed dormancy can be broken by changes in temperature of the environment and other conditions. Physical dormancy can be also broken when the seed goes through the gut of an animal who has consumed it. Mechanical dormancy is broken with the help of some external factors. Example: An animal might break the hard coat of the seed.