NCERT Class 11 Biology Morphology of Flowering Plants Important Notes

ROOT

There are three types of root system, viz. tap root system, fibrous root system and adventitious root system.

Tap Root System:

This type of root system is mainly present in dicotyledonous plants. Direct elongation of the radicle results in formation of primary root. The primary root bears secondary, tertiary, etc. roots. The primary root; along with its branches; makes the tap root system, e.g. mustard, banyan, etc.

Fibrous Root System:

This type of root system is mainly present in monocotyledonous plants. The primary root is short lived after germination. This is replaced by a large number of roots and all of them emerge from the base of the stem. Such roots constitute the fibrous root system, e.g. wheat, paddy, grass, etc.

Adventitious Roots:

Sometimes, roots arise from some other plant parts (other than radicle). Such roots are called adventitious roots. Adventitious roots are used for various purposes; like vegetative propagation, mechanical support, etc.

Functions of Roots:

• Absorption of water and minerals

• Providing anchorage to the plant

• Food storage

• Hormone synthesis

Regions of the Root:

Root Cap: The root is covered at the tip by a thimble like structure. This structure is called root cap. The root cap protects the tender root apex when it makes its way through the soil.

Region of Elongation: This region lies a few millimeters above the root cap. This is the region of meristematic activity. The cells in this region are very small, have thin wall and dense protoplasm. Since this the meristematic region, so the cells divide rapidly. The cells near this region undergo rapid elongation and enlargement. These cells are responsible for the growth of root in length.

Region of Maturation: This region is just above the region of elongation. The cells from the region of elongation differentiate and mature, and then form the region of maturation. The root hairs come out in this region. Root hairs are part of the root epidermis.

Modifications of Root

Root modification for food storage: Tap roots of turnip and carrot and adventitious roots of sweet potato are examples of modification of root for food storage.

Modification for support:

In banyan trees, hanging roots come out from branches. The hanging roots then go into the soil to provide additional support to the huge banyan tree. Such roots are called prop roots. In case of a maize plant, roots emerge out from the lower node of the stem and go into the ground. Such roots are called stilt roots and provide additional support.

Modification for respiration:

In plants which grow in swamps, many roots come out vertically above the ground. These are hollow roots and are called pneumatophores. They facilitate exchange of gases in the roots.

STEM

The ascending part of the plant axis is called stem. The stem bears branches, leaves, flowers and fruits. The stem develops from the plumule of the embryo. Nodes and internodes are present on the stem. Leaves and branches come out from the nodes. The portion between two consecutive nodes is called internode. The buds on stem can be terminal or axillary. Young stem is usually green in colour and subsequently becomes woody and brown.

Functions of Stem:

• Bearing branches, leaves, flowers and fruits.

• Conduction of water and minerals.

• Green stems also carry out photosynthesis.

• Food storage, support, protection and vegetative propagation.

Modifications of Stem

Modification for food storage: The underground stems of potato, ginger, turmeric, zamikand, Colocasia, etc. are modified for food storage. Such modifications are the tools of perenation to tide over unfavourable conditions.

Modifications for climbing: In some plants, stem tendrils develop form axillary buds. These are slender and spirally coiled structures. A tendril helps the plant to climb to a support, e.g. cucumber, pumpkin, grapevine, etc.

Modification for defence: In some plants, the axillary buds are modified into woody, straight and pointed thorns. Such thorns protect the plant from browsing animals, e.g. Citrus, Bougainvillea.

Modification for photosynthesis: In some plants of arid regions, the stems are modified into flattened or fleshy cylindrical structures. The flattened structure can be seen in Opuntia and the cylindrical structure can be seen in Euphorbia. Such structures contain chlorophyll and photosynthesis happens in them.

Modification for vegetative propagation: Stems are modified for vegetative propagation in many plants.

• In some plants, the underground stems spread to new areas and give rise to new plants when the older plants die, e.g. grass and strawberry.

• In some plants, lateral branches come out from the main axis. These branches arch downward to touch the ground; after some growth. These branches then give rise to new plants, e.g. mint and jasmine.

• In some aquatic plants, a lateral branch bears a bunch of leaves and a tuft of roots at nodes. New plants emerge from such nodes, e.g. Pistia and Eichhornia.

• In some plants, the lateral branches emerge from the basal and underground portion of the main stem. Such branches grow horizontally beneath the soil and come out upward to give rise to leafy shoots, e.g. banana, pineapple and Chrysanthemum.

LEAF

A leaf is laterally borne out of the stem. It is usually a flattened structure. The leaf develops at the node. It bears a bud in its axil. The axillary bud subsequently develops into a branch. Leaves originate from shoot apical meristem. They are arranged in acropetal order.

Main parts of leaf are; leaf base, petiole and lamina.

The leaf is attached to the stem by the leaf base. It may bear two lateral small leaf-like structures called stipules. In monocot plants, the leaf base expands to form a sheath. The sheath partially or completely covers the stem.

In some leguminous plants, the leaf base may be swollen. The swollen portion is called the pulvinus. The petiole helps to hold the leaf blade to light. Petiole is flexible and thus allows the lamina to flutter in the wind. This helps in bringing fresh air to the leaf surface and has a cooling effect.

The lamina is expanded green portion of leaf. Veins and veinlets are present on the lamina. The arrangement of veins on a leaf is called venation. There are two types of venation, viz. reticulate and parallel.

a. Reticulate Venation: When the veins and veinlets form a network, this is called reticulate venation. Reticulate venation is usually seen in dicot plants.

b. Parallel Venation: When the veins are parallel to each other, this is called parallel venation. Parallel venation is usually seen in monocot plants.

Types of Leaves

Simple Leaves: When the lamina is entire or when incised; the incisions do not touch the midrib; then the leaf is called simple leaf, e.g. mango, guava, etc.

Compound Leaves: When the incisions on the lamina reach upto the midrib; breaking it into a number of leaflets, then the leaf is called compound leaf, e.g. neem.

A simple way to differentiate between compound and simple leaves is to look for the axillary bud. The bud is always present in case of a leaf but is absent in case of a leaflet.

There are two types of compound leaves, which are as follows:

a. Pinnately Compound Leaf: In this case, a number of leaflets are present on the rachis (common axis). The rachis represents the midrib, e.g. neem.

b. Palmately Compound Leaf: In this case, the leaflets are attached at a common point; at the tip of petiole, e.g. silk cotton.

Phyllotaxy: The arrangement of leaves on the stem or branch is called phyllotaxy. There are three types of phyllotaxy, which are as follows:

a. Alternate: In this type of leaf arrangement, a single leaf arises at each node in alternate manner, e.g. China rose, mustard, sunflower, etc.

b. Opposite: In this type of leaf arrangement, a pair of leaves arise at each node. The leaves lie opposite to each other in this case, e.g. Calotropis, guava, etc.

c. Whorled: In this type of leaf arrangement, more than two leaves arise at a node, e.g. Alstonia.

Modification of Leaves

Tendrils: In some plants, leaves are modified into tendrils to assist in climbing, e.g. pea.

Spines: In some plants, leaves are modified into spines for defence, e.g. cactus. The leaf spine in cacti and in some other xerophytes also helps in reducing water loss by preventing transpiration.

Bulb: In some plants, the leaves are modified into bulb for food storage, e.g. garlic and onion.

INFLORESCENCE

The arrangement of flowers on floral axis is called inflorescence. There are two major types of inflorescence, viz. racemose and cymose.

Racemose Inflorescence: In this type of inflorescence the main axis continues to grow. Flowers are borne laterally in acropetal succession. In case of acropetal succession, the older flowers are at base and the younger flowers are at top.

Cymose inflorescence: In this type of inflorescence, the main axis terminates in a flower. Hence, the growth is limited in cymose inflorescence. Flowers are borne in basipetal order; in this case, which means that the older flowers are at top and younger flowers are at the base.

FLOWER

The flower is a reproductive part of an agiospermic plant. The flower serves the purpose of sexual reproduction. In a typical flower, there are four kinds of whorls. These whorls are successively arranged on the swollen end of the stalk or pedicel. The swollen end of the stalk is called thalamus or receptacle.

Whorls of Flower:

Calyx: The outermost whorl of a flower is called calyx. It is composed of sepals. Sepals are usually green and leaf-like structures. The sepals protect the flower during the bud stage. Calyx is called gamosepalous when sepals are united and is called polysepalous when sepals are free.

Corolla: The second whorl of a flower is called corolla. It is composed of petals. Petals are usually brightly coloured. The bright colours attract the insects and birds for pollination. Corolla is called gamopetalous when petals are united and is called polypetalous when petals are free. Corolla can be tubular, bell-shaped, funnel-shaped or wheel-shaped.

Androecium: The third whorl of a flower is called androecium. It is composed of stamens. A stamen is composed of a stalk and an anther. An anther is usually a bilobed structure. There are two chambers (pollen sacs) in each lobe of an anther. Pollen sacs produce pollen grains. A sterile stamen is called staminode.

Gynoecium: The central whorl of a flower is called gynoecium. It is composed of one or more carpels. A carpel is composed of three parts. The basal swollen portion is called ovary. The long tubular part over ovary is called style and the flat top at the style is called stigma. The style is the receptive surface for pollen grains. Each ovary bears one or more ovules which are attached to a flattened, cushion-like placenta.

Both androecium and gynoecium are present in a bisexual flower, but either of them is present in a unisexual flower.

Symmetry of flowers

1. Actinomorphic: When a flower shows radial symmetry, it is called an actinomorphic flower, e.g. mustard, datura, chilli, etc.

2. Zygomorhphic: When a flower shows bilateral symmetry, it is called a zygomorphic flower, e.g. pea, gulmohar, bean, Cassia, etc.

3. Asymmetric: When a flower cannot be divided into two equal halves from any plane, it is called asymmetric flower, e.g. canna.

Floral parts may be present in multiples of 3, 4 or 5 in a flower. Depending on this, a flower can be trimerous, tetramerous or pentamerous.

Bracteate Flower: The reduced leaf at the base of a flower is called a bract. A flower with bract is called bracteate flower.

Ebracteate Flower: A flower without a bract is called an ebracteate flower.

Types of Flower Based on Position of Ovary

Hypogynous Flower: When the ovary occupies the highest position and other floral parts are below it, the flower is called hypogynous. In this case, the ovary is said to be superior, e.g. mustard, China rose, brinjal, etc.

Perigynous Flower: When the ovary and other parts of the flower are situated at the same level, the flower is called perigynous. In this case, the ovary is said to be half-inferior, e.g. plum, rose, peach, etc.

Epigynous Flower: When the ovary occupies the lowest position and other floral parts are situated above it, the flower is called epigynous flower. In this case, the thalamus grows upwards and completely covers the ovary. In this case, the ovary is said to be inferior, e.g. guava, cucumber, etc.

Aestivation

The mode of arrangement of sepals or petals; with respect to the other members of the same whorl is called aestivation. Following are the main types of aestivation:

a. Valvate: When sepals or petals just touch one another at the margin and don’t overlap, this arrangement is called valvate, e.g. Calotropis.

b. Twisted: When the margin of one sepal or petal overlaps the margin of the next and so on, this arrangement is called twisted, e.g. China rose, okra, cotton, etc.

c. Imbricate: When the margins of sepal or petal overlap one another but the overlapping does not follow a set pattern, this arrangement is called imbricate, e.g. Cassia and gulmohar.

d. Vexillary: When the largest petal overlaps the two lateral petals; which in turn overlap the two smallest anterior petals, this arrangement is called vexillary. The largest petal is called the standard, the lateral petals are called wings and the smallest petals are called keel. Examples: pea and bean.

Type of Attachment of Androecium

a. Epipetalous: When stamens are attached to the petals, this arrangement is called epipetalous, e.g. brinjal.

b. Epiphyllous:When stamens are attached to the perianth, this arrangement is called epiphyllous, e.g. lily.

Arrangement of Stamens

a. Monoadelphous:When stamens are united into one bunch, they are called monoadelphous, e.g. China rose.

b. Diadelphous: When stamens are arranged in two bundles, they are called diadelphous, e.g. pea.

c. Polyadelhpous: When stamens are in more than two bundles, they are called polyadelphous, e.g. citrus.

Arrangement of Gynoecium:

a. Aporcarpous: When carpels are free, they are called apocarpous, e.g. lotus and rose.

b. Syncarpous: When carpels are fused, they are called syncarpous, e.g. mustard and tomato.

Placentation

The arrangement of ovules in the ovary is called placentation. There are different types of placentation which are as follows:

a. Marginal: When the placenta forms a ridge along the ventral suture of the ovary and ovules are borne on this ridge; in two rows, this arrangement is called marginal, e.g. pea.

b. Axile: When the placenta is axial and the ovules are attached to it in a multiclocular ovary, this arrangement is called axile, e.g. China rose, tomato and lemon.

c. Parietal: When ovules develop on the inner wall of the ovary or on peripheral part, this arrangement is called parietal, e.g. mustard and argemone.

d. Central: When ovules develop on the central axis and septa are absent, this arrangement is called free-central, e.g. dianthus and primrose.

e. Basal: When the placenta develops at the base of the ovary and a single ovule is attached to it, this arrangement is called basal, e.g. sunflower, marigold.

FRUIT

Fruit is a mature, ripened ovary which develops after fertilization. If a fruit develops without fertilization, it is called parthenocarpic fruit.

A fruit usually consists of a wall and seeds. The wall of the fruit is called pericarp. The pericarp can be dry or fleshy. A fleshy pericarp is differentiated into three layers, viz. epicarp, mesocarp and endocarp.

SEED

Ovules develop into seeds after fertilization. A seed is composed of a seed coat and an embryo. The embryo is composed of a radicle, an embryonal axis and one or two cotyledons.

Structure of a Dicotyledonous Seed

1. The outermost covering of the seed is called seed coat. The seed coat is composed of two layers. The outer layer is called testa and the inner layer is called tegmen.

2. There is a scar on the seed coat through which the developing seed was attached to the fruit. This scar is called hilum. There is a small pore above the hilum; called micropyle.

3. The embryo lies within the seed coat. It is composed of an embryonal axis and two cotyledons. Cotyledons are usually fleshy and contain reserve food materials.

4. Radicle and plumule are present at the two ends of the embryonal axis.

Endosperm is present in some seeds. Such seeds are called endospermous. When endosperm is not present in mature seeds, the seeds are called non-endospermous.

Structure of Monocotyledonous Seed

Monocoltyedonous seeds are usually endospermic, but some are non-endospermic, e.g. orchids.

In the seeds of cereals, the seed coat is membranous and is usually fused with the fruit wall.

The endosperm is bulky and stores food. The outer covering of endosperm separates the embryo by a proteinous layer. This layer is called aleurone layer.

The embryo of monocot seed is small. It is situated at one end of the endosperm. It consists of one large and shield-shaped cotyledon which is known as acutellum. There is a short embryonal axis; with radicle and plumule.

The plumule and radicle are enclosed in sheaths which are respectively called coleoptiles and coleorrhiza.

SEMI-TECHNICAL DESCRIPTION OF A TYPICAL FLOWERING PLANT

The semi-technical description of a typical flowering plant should be brief. It should be written in simple and scientific language. It should be in proper sequence. The description begins with habit, vegetative characters and then floral characters, inflorescence and floral parts.

Fusion of floral part is indicated by enclosing the figure within bracket. Adhesion of floral parts is indicated by drawing a line above the symbols of the floral parts. A floral diagram gives the information about the number of different parts of a flower, their arrangement and their relation with one another. The position of the mother axis is shown by a dot on top of the floral diagram. Different whorls of the flower are drawn in correct sequence.

DESCRIPTION OF SOME IMPORTANT FAMILIES

Fabaceae

This family was earlier called Papilonoideae, a subfamily of family Leguminosae. It is distributed all over the world.

Vegetative Characters :- Trees, shrubs, herbs; root with root nodules

Stem :- erect or climber

Leaves :- alternate, pinnately compound or simple; leaf base, pulvinate; stipulate; venation reticulate.

Floral characters

Inflorescence :- racemose

Flower :- bisexual, zygomorphic

Calyx :- sepals five, gamosepalous; imbricate aestivation

Corolla :- petals five, polypetalous, papilionaceous, consisting of a posterior standard, two lateral wings, two anterior ones forming a keel (enclosing stamens and pistil), vexillary aestivation

Androecium :- ten, diadelphous, anther dithecous

Gynoecium :- ovary superior, mono carpellary, unilocular with many ovules, style single

Fruit :- legume; seed: one to many, non-endospermicEconomic importance: Many plants belonging to the family are sources of pulses (gram, arhar, sem, moong, soyabean; edible oil (soyabean, groundnut); dye (indigofera); fibres (sunhemp); fodder (Sesbania, Trifolium), ornamentals (lupin, sweet pea); medicine (muliathi).

Solanaceae

It is a large family, commonly called as the ‘potato family’. It is widely distributed in tropics, subtropics and even temperate zones.

Vegetative Characters :- Plants mostly, herbs, shrubs and small trees

Stem :- herbaceous rarely woody, aerial; erect, cylindrical, branched, solid or hollow, hairy or glabrous, underground stem in potato (Solanum tuberosum)

Leaves :- alternate, simple, rarely pinnately compound, exstipulate; venation reticulate

Floral Characters

Inflorescence :- Solitary, axillary or cymose as in Solanum

Flower :- bisexual, actinomorphic

Calyx :- sepals five, united, persistent, valvate aestivation

Corolla :- petals five, united; valvate aestivation

Androecium :- stamens five, epipetalous

Gynoecium :- bicarpellary, syncarpous; ovary superior, bilocular, placenta swollen with many ovules

Fruits :- berry or capsule

Seeds :- many, endospermous

Floral Formula

Economic Importance :- Many plants belonging to this family are source of food (tomato, brinjal, potato), spice (chilli); medicine (belladonna, ashwagandha); fumigatory (tobacco); ornamentals (petunia).

Liliaceae

Commonly called the ‘Lily family’ is a characteristic representative of monocotyledonous plants. It is distributed world wide.

Vegetative characters :- Perennial herbs with underground bulbs/corms/ rhizomes

Leaves :- mostly basal, alternate, linear, exstipulate with parallel venation

Floral characters

Inflorescence :- solitary / cymose; often umbellate clusters

Flower :- bisexual; actinomorphic

Perianth :- petal six (3+3), often united into tube; valvate aestivation

Androcium :- stamen six, (3+3)

Gynoecium :- tricarpellary, syncarpous, ovary superior, trilocular with many ovules; axile placentation

Fruit :- capsule, rarely berry

Seed :- endospermous

Economic Importance :- Many plants belonging to this family are good ornamentals (tulip, Gloriosa), source of medicine (Aloe), vegetables (Asparagus), and colchicine (Colchicum autumnale).

NCERT Solution for Class 11 Biology Morphology of Flowering Plants Important Notes

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

(a) Banyan tree (b) Turnip (c) Mangrove trees

Answer: Sometimes, roots are modified to serve some functions other than its main function of providing anchorage and absorption of water and minerals.

a. Banyan Tree: In banyan trees, hanging roots come out from branches. The hanging roots then go into the soil to provide additional support to the huge banyan tree. Such roots are called prop roots.

b. Turnip: The tap root in turnip is modified for food storage.

c. Mangrove trees: Mangrove trees are found in marshy area. In such plants, many roots come out vertically above the ground. These are hollow roots and are called pneumatophores. They facilitate exchange of gases in the roots.

Question 2. Justify the following statements on the basis of external features:

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

Answer: In some plants, stems are also underground for some additional purpose; like food storage and vegetative propagation. Presence of scaly leaves on potato and ginger shows that they are not roots rather stems.

(ii) Flower is a modified shoot.

Answer: Flower comes out of stem hence it is a shoot. It serves the special purpose of sexual reproduction. Hence, flower is called a modified shoot.

Question 3. How is a pinnately compound leaf different from a palmately compound leaf?

Answer: Leaflets are present on a common axis (rachis); in case of pinnately compound leaves. In palmately compound leaves, the leaflets originate from the apex of the midrib.

Question 4. Explain with suitable examples the different types of phyllotaxy.

Answer: Phyllotaxy: The arrangement of leaves on the stem or branch is called phyllotaxy. There are three types of phyllotaxy, which are as follows:

a. Alternate: In this type of leaf arrangement, a single leaf arises at each node in alternate manner, e.g. China rose, mustard, sunflower, etc.

b. Opposite: In this type of leaf arrangement, a pair of leaves arise at each node. The leaves lie opposite to each other in this case, e.g. Calotropis, guava, etc.

c. Whorled: In this type of leaf arrangement, more than two leaves arise at a node, e.g. Alstonia.

Question: 5. Define the following terms:

(a) aestivation (b) placentation (c) actinomorphic (d) zygomorphic (e) superior ovary (f) perigynous flower (g) epipetalous stamen

Answer:

a. Aestivation: The mode of arrangement of sepals or petals; with respect to the other members of the same whorl is called aestivation.

b. Placentation: The arrangement of ovules in the ovary is called placentation.

c. Actinomorphic: When a flower shows radial symmetry, it is called an actinomorphic flower, e.g. mustard, datura, chilli, etc.

d. Zygomorphic: When a flower shows bilateral symmetry, it is called a zygomorphic flower, e.g. pea, gulmohar, bean, Cassia, etc.

e. Superior Ovary or Hypogynous Flower: When the ovary occupies the highest position and other floral parts are below it, the flower is called hypogynous. In this case, the ovary is said to be superior, e.g. mustard, China rose, brinjal, etc.

f. Perigynous Flower: When the ovary and other parts of the flower are situated at the same level, the flower is called perigynous. In this case, the ovary is said to be half-inferior, e.g. plum, rose, peach, etc.

g. Epipetalous Stamens: When stamens are attached to the petals, this arrangement is called epipetalous, e.g. brinjal.

Question 6. Differentiate between

(a) Racemose and cymose inflorescence

Answer:

(b) Fibrous root and adventitious root

Answer: 

c) Apocarpous and syncarpous ovary

Answer: Carpels are free in apocarpous ovary, while they are fused in syncarpous ovary.

Question 7. Describe modifications of stem with suitable examples.

Answer: Modifications of Stem

Modification for food storage: The underground stems of potato, ginger, turmeric, zamikand, Colocasia, etc. are modified for food storage. Such modifications are the tools of perenation to tide over unfavourable conditions.

Modifications for climbing: In some plants, stem tendrils develop form axillary buds. These are slender and spirally coiled structures. A tendril helps the plant to climb to a support, e.g. cucumber, pumpkin, grapevine, etc.

Modification for defence: In some plants, the axillary buds are modified into woody, straight and pointed thorns. Such thorns protect the plant from browsing animals, e.g. Citrus, Bougainvillea.

Modification for photosynthesis: In some plants of arid regions, the stems are modified into flattened or fleshy cylindrical structures. The flattened structure can be seen in Opuntia and the cylindrical structure can be seen in Euphorbia. Such structures contain chlorophyll and photosynthesis happens in them.

Modification for vegetative propagation: Stems are modified for vegetative propagation in many plants, e.g. grass, berry, dahlia, etc.

Question 8. What is a flower? Describe the parts of a typical angiosperm flower.

Answer: The flower is a reproductive part of an agiospermic plant. The flower serves the purpose of sexual reproduction. In a typical flower, there are four kinds of whorls. These whorls are successively arranged on the swollen end of the stalk or pedicel. The swollen end of the stalk is called thalamus or receptacle.

Whorls of Flower:

Calyx: The outermost whorl of a flower is called calyx. It is composed of sepals. Sepals are usually green and leaf-like structures. The sepals protect the flower during the bud stage. Calyx is called gamosepalous when sepals are united and is called polysepalous when sepals are free.

Corolla: The second whorl of a flower is called corolla. It is composed of petals. Petals are usually brightly coloured. The bright colours attract the insects and birds for pollination. Corolla is called gamopetalous when petals are united and is called polypetalous when petals are free. Corolla can be tubular, bell-shaped, funnel-shaped or wheel-shaped.

Androecium: The third whorl of a flower is called androecium. It is composed of stamens. A stamen is composed of a stalk and an anther. An anther is usually a bilobed structure. There are two chambers (pollen sacs) in each lobe of an anther. Pollen sacs produce pollen grains. A sterile stamen is called staminode.

Gynoecium: The central whorl of a flower is called gynoecium. It is composed of one or more carpels. A carpel is composed of three parts. The basal swollen portion is called ovary. The long tubular part over ovary is called style and the flat top at the style is called stigma. The style is the receptive surface for pollen grains. Each ovary bears one or more ovules which are attached to a flattened, cushion-like placenta.

Question 9. How do the various leaf modifications help plants?

Answer: Modification of Leaves

Tendrils: In some plants, leaves are modified into tendrils to assist in climbing, e.g. pea.

Spines: In some plants, leaves are modified into spines for defence, e.g. cactus. The leaf spine in cacti and in some other xerophytes also helps in reducing water loss by preventing transpiration.

Bulb: In some plants, the leaves are modified into bulb for food storage, e.g. garlic and onion.

Important Questions for NCERT Class 11 Biology Morphology of Flowering Plants

Ques. The term ‘polyadelphous’ is related to
(a) gynoecium     (b) androecium
(c) corolla           (d) calyx. 

Answer: B

Ques. How many plants among Indigofera, Sesbania, Salvia, Allium, Aloe, mustard, groundnut, radish, gram and turnip have stamens with different lengths in their flowers?
(a) Three         (b) Four
(c) Five            (d) Six 

Answer: B

Ques. Radial symmetry is found in the flowers of
(a) Brassica             (b) Trifolium
(c) Pisum                (d) Cassia.

Answer: A

Ques. Free central placentation is found in
(a) Dianthus      (b) Argemone
(c) Brassica       (d) Citrus.

Answer: A

Ques. The standard petal of a papilionaceous corolla is also called
(a) vexillum     (b) corona
(c) carina        (d) pappus. 

Answer: A

Ques. Among China rose, mustard, brinjal, potato, guava, cucumber, onion and tulip, how many plants have superior ovary?
(a) Three          (b) Four
(c) Five            (d) Six

Answer: D

Ques. Axile placentation is present in
(a) pea            (b) Argemone
(c) Dianthus     (d) lemon. 

Answer: D

Ques. Keel is the characteristic feature of flower of
(a) Aloe          (b) tomato
(c) tulip          (d) Indigofera.

Answer: D

Ques. When the margins of sepals or petals overlap one another without any particular direction, the condition is termed as
(a) vexillary         (b) imbricate
(c) twisted           (d) valvate. 

Answer: B

Ques. Among bitter gourd, mustard, brinjal, pumpkin, china rose, lupin, cucumber, sunhemp, gram, guava, bean, chilli, plum, Petunia, tomato, rose, Withania, potato, onion, Aloe and tulip how many plants have hypogynous flower?
(a) Fifteen         (b) Eighteen
(c) Six              (d) Ten 

Answer: A

Ques. In China rose, the flowers are
(a) zygomorphic, hypogynous with imbricate aestivation
(b) zygomorphic, epigynous with twisted aestivation
(c) actinomorphic, hypogynous with twisted aestivation
(d) actinomorphic, epigynous with valvate aestivation. 

Answer: C

Ques. Among flowers of Calotropis, tulip, Sesbania, Asparagus, Colchicum, sweet pea, Petunia, Indigofera, mustard, soybean, tobacco and groundnut, how many plants have corolla with valvate aestivation?
(a) Six          (b) Seven
(c) Eight       (d) Five

Answer: B

Ques. Placentation in tomato and lemon is
(a) parietal          (b) free central
(c) marginal        (d) axile. 

Answer: D

Ques. The gynoecium consists of many free pistils in flowers of
(a) Aloe               (b) tomato
(c) Papaver          (d) Michelia. 

Answer: D

Ques. How many plants in the list given below have marginal placentation?
Mustard, Gram, Tulip, Asparagus, Arhar, Sun- hemp,
Chilli, Colchicum, Onion, Moong, Pea, Tobacco,Lupin
(a) Four       (b) Five
(c) Six         (d) Three 

Answer: C

Ques. Flowers are zygomorphic in
(a) mustard        (b) gulmohor
(c) tomato          (d) Datura. 

Answer: B

Ques. The ovary is half inferior in flowers of
(a) peach        (b) cucumber
(c) cotton        (d) guava.

Answer: A

Ques. In unilocular ovary with a single ovule, the placentation is
(a) marginal           (b) basal
(c) free central        (d) axile.

Answer: B

Ques. Keel is characteristic of the flowers of
(a) gulmohur          (b) Cassia
(c) Calotropis          (d) bean. 

Answer: D

Ques. Ovary is half inferior in the flowers of
(a) guava     (b) plum
(c) brinjal     (d) cucumber. 

Answer: B

Ques. The technical term used for the androecium in a flower of China rose (Hibiscus rosa sinensis) is
(a) monadelphous      (b) diadelphous
(c) polyandrous          (d) polyadelphous.

Answer: A

Ques. An example of axile placentation is
(a) Dianthus       (b) lemon
(c) marigold       (d) Argemone. 

Answer: B

Ques. Replum is present in the ovary of flower of
(a) sunflower    (b) pea
(c) lemon         (d) mustard. 

Answer: D

Ques. Angiosperm, to which the largest flowers belong, is
(a) total root parasite     (b) partial root parasite
(c) total stem parasite    (d) partial stem parasite.

Answer: A

Ques. Coconut fruit is a
(a) berry         (b) nut
(c) capsule      (d) drupe. 

Answer: D

Ques. The morphological nature of the edible part of coconut is
(a) cotyledon     (b) endosperm
(c) pericarp       (d) perisperm.

Answer: B