NEET BIOLOGY Unit 20 MORPHOLOGY IN FLOWERING PLANTS

NEET BIOLOGY Unit 20 

MORPHOLOGY IN FLOWERING PLANTS

INTRODUCTION : 

 

Morphology – (Morphe = form + logos = study). It deals with the study of forms and features of different plant organs like roots, stems, leaves, flowers, seeds, fruits etc.
The body of a typical angiospermic plant is differentiated into :
(1) An underground root system
(2) An aerial shoot system.
The shoot system consists of stem (including branches), leaves, flowers and fruits.
The roots, stems and leaves are vegetative parts, while flowers constitute the reproductive part.
CLASSIFICATION OF PLANTS :
Depending upon their life span, plants are classified as –
a. Annuals – Plants that complete their life cycle in one year or single growing season or few weeks to a few months. They pass the unfavourable period in the form of seeds eg. Mustard, Pea.
b. Biennials – Plants that complete their life cycle in two years-growing, vegetative and storing food in the first year, flowering and fruiting in the second year. They die off after producing flowers and fruits. Radish, turnip, carrot are biennial in colder areas. They become annual in warmer places.
c. Perennials – Plants that survives for several years. These plants usually bears flowers and fruits every year and do not die after producing flowers. eg. Mango, Banana, Guava.

ROOT
Radicle comes out/arise from the seed coat in the form of soft structure and move toward the soil. It develops and forms primary root.
General Characters :
1. Roots are non green, underground, (+) geotropic, (–) phototropic and (+) hydrotropic.
2. Buds present for vegetative propagation in sweet potato (Ipomea) and Indian red wood (Dalbergia)
3. Roots do not bear buds, nodes and internodes
4. Roots have unicellular root hairs.
TYPES OF ROOTS :
Roots are of two types :
1. Tap root
MORPHOLOGY IN FLOWERING PLANTS
2. Adventitious root
Tap root : It develops from radicle and made up of one main branch and other sub branches.
Adventitious roots : When root is originated from any other part of plant than radicle. It is known as Adventitious root.
Root System :
Root systems are of two type :
(i) Tap Root System,
(ii) Fibrous Root System
(i) Tap root system - Primary root and its branches constitute tap root system. e.g., Dicot
(ii) Fibrous root system – In some plant mainly in monocots, after sometime growth of tap root stop and than roots develop from other part of plant which are highly branched and fibrous and form fibrous root system.
REGIONS OF ROOTS :
Morphologically four distinct regions are present in roots.
Root cap : It is terminal structure. It protects tender apex of root.
Meristematic zone : Cells of this regions are very small and thin walled. They divide repeatedly and increase cell number
Elongation region : The cells proximal to meristematic zone undergo rapid elongation and enlargement and are responsible for rapid growth of roots.
Maturation region : Cells proximal to region of elongation gradually differentiate and mature. Root hairs are present in maturation zone.
MODIFICATION OF ROOTS :
1. Modified tap root for storage :
Conical roots : These roots are thicker at their upper side and tapering at basal end. eg. Carrot.
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BIOLOGY FOR NEET & AIIMS
FAMILIES OF ANGIOSPERMS :
The symbols used in Floral Formula -

Adhesion

CRUCIFERAE (BRASSICACEAE) (Mustard family)
Distinguishing Features of Cruciferae -
The plant organs usually have pungent odour. This odour is due to presence of sulphur containing glucosides compound. Myrosin enzyme (present in secondary cells) hydrolyse then into glucose & different isothiocyanates (Various oils).
Inflorescence – Typical raceme.
BIOLOGY FOR NEET & AIIMS
1. Direct elongation of the radicle leads to the formation of primary root and lateral roots are called secondary and
tertiary roots, (are collectively called tap root system). eg most of the dicot plants (Mustard).
2. In monocots primary root is replaced by the large numbers of roots which is originated from the base of stem called
fibrous roots. eg - wheat
3. Roots arise from parts of the plant other than radicle are called adventitious roots. eg. Grass, Monstera, Banyan.

4. STEM
It develops from the plumule. The main function of the stem is spreading out branches bearing leaves, flowers and
fruits.
MODIFICATIONS OF STEM
 For food strage-underground stem (Potato, ginger, turmeric, zaminkand, Colocasia)
 Stem tendrils - Help plants to climb
e.g.- Gourds (Cucumber, Pumpkins, Watermelon) and grapevines
 Thoms - Protect plants from browsing animals
e.g - Citrus, Bougainvillea.
 Phylloclade - Perform photosynthesis
e.g. - Opuntia (Flat), Euphorbia (Cylindrical)
 Offset - Pistia, Eichhornia
 Sucker - Banana, Pineapple, Chrysanthemum
5. LEAF
Leaves originate from shoot apical meristem and are arranged in an acropetal manner.
The leaf is attached to the stem by leaf base and may bear two lateral small leaf like structures called stipules.
Swollen leaf bases are called pulvinus. e.g. Some leguminous plants.

Reticulate
Veinlets form network
(Dicots)
Parallel
Vein run parallel to each other
(Monocots)
BIOLOGY FOR NEET & AIIMS
Ex.1 If a primary root continues to grow, the type of root
system will be known as
(A) Secondary (B) Fibrous
(C) Tap (D) Stilt
Sol. (C)
Ex.2 Roots developing from plant parts other than radical
are
(A) Epiphyllous (B) Epicaulous
(C) Adventitious (D) Fibrous
Sol. (C) : In monocotyledonous plants the radicle dies
immediately after germination of seeds and later
these roots arise from any germination of seeds
and later these roots arise from any other portion
(stem, leaves etc.) of the plant.
Ex.3 In which the pneumatophores are found
(A) Tinospora (B) Pinus
(C) Rhizophora (D) None of these
Sol. (C) : Pneumatophores develop from horizontal
roots. They bear a number of lenticels or
pneumathodes. Exchange of gases occurs through
these pores. e.g., Rhizophora.
Ex.4 Stilt roots which grow obliquely from basal nodes
of culm stem and acting as brace are found in
(A) Sorghum (B) Maize
(C) Sugarcane (D) All of these
Sol. (D)
Ex.5 Find out correct order of vegetative propagules of
plants like potato, ginger Agave, Bryophyllum and
water hyacinth
(A) Offset, bulbil, leaf bud, rhizome and eyes
(B) Leaf bud, bulbil, offset, rhizome and eyes
(C) Rhizome, bulbil, leaf bud, eyes and offset
(D) Offset, bulbil, leaf bud, rhizome and eyes
Sol. (C)
Ex.6 Thorn is a stem structure beacuse it
(A) Develops from thrunk
(B) Develops from axillary bud
(C) Grows from external surface
(D) Is pointed
Sol. (B) : Thorns are actually modified axillary buds or
terminal buds, and they possess vascular supply.
Ex.7 An example of edible underground stem is
(A) Sweet potato (B) Potato
(C) Carrot (D) Groundnut
Sol. (B) : Sweet potato, Carrot – Edible root.
Potato – Edible underground stem.
Ex.8 Which one of the following is correctly matched
(A) Onion - Bulb
(B) Ginger - Sucker
(C) Chlamydomonas - Conidia
(D) Yeast - Zoospores
Sol. (A) : Onion – Bulb – underground stem, Ginger –
Rhizome - Chlamydomonas – Zoospore.
Ex.9 Succulent stem is found in
(A) Pisum (B) Casuarina
(C) Oxalis (D) Euphorbia
Sol. (D)
Ex.10 Presence of sheathing leaf base and ligule are
characteristic of
(A) Cycas leaf (B) Fern leaf
(C) Banana leaf (D) Grass leaf
Sol. (D) : In grassses and many monocots, the leaf base
is broad and surrounds the stem as an envelope,
such a leaf base is called sheathing leaf base. An
additional outgrowth is present between leaf base
and lamina. It is called ligule, e.g., Grasses.
Ex.11 Identify the correct types of phyllotaxy which
shown in the following figures
(A) A - Whorled, B - Alternate, C - Opposite
(B) A - Alternate, B - Whorled, C - Opposite
(C) A - Whorled, B - Opposite, C - Alternate
(D) A - Alternate, B - Opposite, C - Whorled
Sol. (D)
Ex.12 Study the following statements and select the
correct option
(A) Buds are present in the axil of leaflets of the
compound leaf
(B) Pulvinus leaf-base is present in some
leguminous plants
(C) In Alstonia, the petioles expand, become green
and synthesize food
(D) Opposite phyllotaxy is seen in guava
(A) (B) and (D) are correct but (A) and (C) are worng
(B) (A) and (C) are correct but (B) and (D) are worng
(C) (B), (C) and (D) are correct but (A) are worng
(D) (A) and (B) are correct but (C) and (D) are worng
Sol. (A)
SOLVED EXAMPLE
1. Roots developing from plant parts other than radicle
are -
(A) Tap root (B) Adventitious root
(C) Both (A) & (B) (D) None of the above
2. A plant with parallel venation is -
(A) Castor (B) Grass
(C) Colocasia (D) Mustard
3. An edible inflorescence is -
(A) Brassica rapa (B) Mustard
(C) Raphanus sativus (D) Brassica oleracea
4. Main function of leaf is -
(A) Manufacture of food (B) Exchange of gases
(C) Both (A) and (B) (D) None of the above
5. Cruciform corolla is found in -
(A) Pea (B) China rose
(C) Radish (D) Sunflower
6. Siliqua is the fruit of -
(A) Cruciferae (B) Malvaceae
(C) Liliaceae (D) Solanaceae
7. Chlorophyll containing fleshy cylindrical structures
found in Euphorbia are modified
(A) Roots (B) Fruit
(C) Leaves (D) Stem
8. In Pistia and and Eichhornia, stems are modified to
form
(A) Offsets (B) Tendrils
(C) Stolons (D) Suckers
9. Leaves originate from _______ and modified to form
(A) Root apical meristem, acropetal
(B) Floral meristem, basipetal
(C) Shoot apical meristem, acropetal
(D) Internodes, basipetal
10. Leaf base may bear two lateral small leaf like
structures called
(A) Lamina (B) Pulvinus
(C) Stipules (D) Sepals
11. Mark the incorrect statement
(A) Flower is a modified shoot
(B) In cymose inflorescence, the main axis terminates
in a flower
(C) Flower are borne on successive internodes on
the stems and roots
(D)When a shoot tip transforms into a flower, the
flower is always solitary
12. The four whorls of a flower are arranged on the
(A) Thalamus (B) Petiole
(C) Corolla (D) Stamens
13. Radial symmetry is found in flowers of
(A) Cassia (B) Chilli
(C) Gulmohur (D) Canna
14. The flower of which of the following plants is
zygomorphic ?
(A) Bean (B) Datura
(C) Mustard (D) Canna
15. Which of the following plant has epigynous flower
?
(A) Cucumber (B) Brinjal
(C) Mustard (D) Peach
16. Parallel venation is a characteristic of monocots.
Which of the following is an exception to this
generalization?
(A) Smilax (B) Colocasia
(C) Alocasia (D) All of these
17. Carpels are fused in the flowers of
(A) Lotus (B) Tomato
(C) Rose (D) Both (A) & (C)
18. The stony hard part of the mango represents
(A)Mesocarp (B) Epicarp
(C) Endocarp (D) Marginal
Exercise # 1 SINGLE OBJECTIVE NEET LEVEL
BIOLOGY FOR NEET & AIIMS
1. Occurence of different types of leaves on the same
plant is -
(A) Heterophylly (B) Heteotrophy
(C) Heteronasty (D) All
2. Which one of the following is of related type -
(A) Catkin and Hypanthodium
(B) Raceme and Cyathium
(C) Corymb and Umbel
(D) Verticillaster and spike
3. Didynamous condition is related to -
(A) Androecium (B) Inflorescence
(C) Gynoecium (D) All
4. The floral organs arise from -
(A) Mother axis (B) Thalamus
(C) Root (D) Pedicel
5. A typical flower with superior ovary and other floral
parts inferior is -
(A) Polygamous (B) Hypogynous
(C) Perigynous (D) Epigynous
6. A characteristic of angiosperm is -
(A) Flowers (B) Roots
(C) Seed (D) All
7. A berry fruit is -
(A) Fleshy and single seeded
(B) Fleshy and multiseeded
(C) Dry and multiseeded
(D) Dehiscent & single seeded
8. Water melon is -
(A) Pome (B) Sorosis
(C) Pepo (D) Drupe
9. Fruit of Halianthus annuas is -
(A) Legume (B) Follicle
(C) Cypsella (D) Capsule
10. Monadelphous stamens are formed by the fusion
of –
(A) Anther lobes of all stamens
(B) Anther lobes of two stamens
(C) Filaments of all stamens
(D) None of these
11. In a ‘phylloclade’ the function of photosynthesis is
taken up by -
(A) Leaves (B) Stipules
(C) Stem (D) Buds
12. Plants disperse their seeds and fruits because –
(A) The produce them
(B) They are good and edible
(C)They want to eliminate struggle for existence
(D) None of the above
13. Rolling mechanism of dispersal is found in –
(A) Amaranthus (B) Acer
(C) Shorea (D) Moringa
14. Clove is –
(A) Bud (B) Fruit
(C) Seed (D) Mature flower
15. A perennial plant which flower once in its life time is
known as
(A) Annual (B) Perennial
(C) Monocarpic (D) Polycarpic
16. Imparipinnate leaf is characterized by –
(A) Large leaflet
(B) Rachis terminating in by unpaired odd leaflet
(C) Strong Rachis
(D) Leaflets are in pair
17. Presence of monocarpellary, unilocular ovary with
marginal placentation are characteristic of–
(A) Solanaceae (B) Cruciferae
(C) Leguminosae (D) Compositae
18. Thorns and spines are -
(A) Defensive organs
(B) Respiratory organs
(C) Both (A) & (B)
(D) Storage organs
Exercise # 2 SINGLE OBJECTIVE AIIMS LEVEL
MORPHOLOGY IN FLOWERING PLANTS
1. Match the items in Column - I with column - II and choose the correct alternative
Column - I Column - II
A. Tubercular storage roots i. Tinospora
B. Pneumatophores ii. Heritiera
C. Haustoria iii. Asparagus
D. Prop-roots iv. Viscum
E. Assimilatory roots v. Screwpine
(A) A - ii, B - iii, C - iv, D - v, E - i (B) A - iii, B - iv, C - v, D - i, E - ii
(C) A -iii, B - i, C - ii, D - v, E - iv (D) A - v, B - iv, C - v, D - ii, E - i
(E) A - iii, B - ii, C - iv, D - v, E - i
2. Match the following and select the correct combination from the options given below
Column - I Column - II
(Stem Modifications) ( Found in)
A. Underground stem i. Euphorbia
B. Stem tendril ii. Opuntia
C. Stem thorns iii. Potato
D. Flattened stem iv. Citrus
E. Fleshy cylindrical stem v. Cucumber
(A) A - ii, B - iii, C - iv, D - v, E - i (B) A - iii, B - iv, C - v, D - i, E - ii
(C) A - iii, B - i, C - ii, D - v, E - iv (D) A - v, B - iv, C - v, D - ii, E - i
(E) A - iii, B - ii, C - iv, D - v, E - i
3. Study the following lists
Column- I Column- II
A. Entire leaf modified into a spine i. Clematis
B. Leaf except stipules modified into a tendril ii. Citrus
C. Stipules modified into a tendril iii. Euphorbia
D. First leaf of axillary bud modified into a spine iv. Lathyrus
v. Smilax
The correct match is
A B C D
(A) iii iv i ii
(B) iii i iv ii
(C) ii iii i v
(D) v ii i iii
4. Match list I with list II and select the correct option
Column- I Column- II
A. Gemmules i. Agave
B. Leaf-buds ii. Penicillium
C. Bulbil iii.Water hyacinth
D. Offset iv. Sponges
E. Conidia v. Bryophyllum
(A) A - 4, B - 5, C - 1, D - 3, E - 2 (B) A - 4, B - 3, C - 2, D - 1, E - 5
(C) A - 3, B - 5, C - 4, D - 2, E - 1 (D) A - 4, B - 1, C - 5, D - 3, E - 2
(E) A - 3, B - 5, C - 4, D - 1, E - 2
Exercise # 3 PART - 1 MATRIX MATCH COLUMN
BIOLOGY FOR NEET & AIIMS
1. Edible part in lichi is [CBSE AIPMT-1999, 05, 06]
(A) mesocarp (B) fleshy aril
(C) endosperm (D) pericarp
2. Match the following and indicate which is correct ?
[CBSE AIPMT-2000]
(A) Cucurbitaceae - Orange
(B) Malvaceae - Cotton
(C) Brassicaceae - Wheat
(D) Leguminosae - Sunflower
3. Edible part of banana is [CBSE AIPMT-2001]
(A) epicarp
(B) mesocarp and less developed endocarp
(C) endocarp and less developed mesocarp
(D) epicarp and mesocarp
4. Which is correct pair for edible part ?
[CBSE AIPMT-2001]
(A) Tomato - Thalamus
(B) Maize - Cotyledons
(C) Guava - Mesocarp
(D) Date plam - Pericarp
5. Roots of which plant contains an oxidising agent ?
[CBSE AIPMT-2001]
(A) Carrot (B) Soyabean
(C) Mustard (D) Radish
6. Bicarpellary gynoecium and oblique ovary occurs
in [CBSE AIPMT-2001]
(A) mustard (B) banana
(C) Pisum (D) brinjal
7. Geocarpic fruit is [CBSE AIPMT-2002]
(A) potato (B) groundnut
(C) onion (D) garlic
8. Edible part in mango is [CBSE AIPMT-2002,04]
(A) mesocarp (B) epicarp
(C) endocarp (D) epidermis
9. Which of the following is a correct pair ?
[CBSE AIPMT-2002]
(A) Cuscuta - Parasite
(B) Dischidia - Insectivorous
(C) Opuntia - Predator
(D) Capsella - Hydrophyte
10. Juicy hair-like structures observed in the femon fruit
develop from [CBSE AIPMT-2003]
(A) mesocarp and endocarp
(B) exocarp
(C) mesocarp
(D) endocarp
11. Long filamentous threads protruding at the end of
the young cob of maize are[CBSE AIPMT-2006]
(A) styles (B) ovaries
(C) hairs (D) anthers
12. In a cereal grain the single cotyledon of embryo is
represented by [CBSE AIPMT-2006]
(A) scutellum (B) prophyll
(C) coleoptile (D) coleorhiza
13. Pineapple (ananas) fruit develops from
[CBSE AIPMT-2006]
(A) a multipistillate syncarpous flower
(B) a cluster of compactly borne flowers on a common
axis
(C) a multilocular monocarpellary flower
(D) a unilocular polycarpellary flower
14. What type of placentation is seen sweet pea ?
[CBSE AIPMT-2006]
(A) Axile (B) Free central
(C) Marginal (D) Basal
15. Dry indehiscent single- seeded fruit formed from
bicarpellary syncarpous inferior ovary is
[CBSE AIPMT-2008]
(A) caryopsis (B) cypsela
(C) berry (D) cremocarp
Exercise # 4 PART - 1 PREVIOUS YEAR (NEET/AIPMT)
IIT-JEE | PRE-MEDICAL | CBSE | FOUNDATION
MORPHOLOGY IN FLOWERING PLANTS
1. Assertion : Presence of pneumatophores is a special adaptation of hydrophytes.
Reason : Pneumatophores are positively geotropic shoots that have lenticels and help in gaseous exchange.
(A) If both assertion and reason are true and reason is the correct explanation of assertion.
(B) If both assertion and reason are true but reason is not the correct explanation of assertion.
(C) If assertion is true but reason is false.
(D) If both assertion and reason are false.
2. The modified supporting roots called prop roots and stilt roots are seen respectively in
(i) banyan and maize (ii) banyan and sugarcane
(iii) maize and banyan (iv) sugarcane and maize.
(A) (i) only (B) (ii) only
(C) (iii) only (D) (i) and (ii) only
(E) (i) and (iv) only
3. Which of the following is correctly matched.
(A) Monstera – Fibrous root (B) Dahlia – Fasciculated root
(C) Azadirachta – Adventitious root (D) Basil – Prop roots
4. Select the correct statements.
(A) From the region of elongation, some of the epidermal cells form root hairs.
(B) Pneumatophores are seen in Rhizophora.
(C) Adventitious rroots are seen in the banyan tree.
(D)Maize and sugarcane have prop roots.
(A) (A) and (D) (B) (A), (C) and (D)
(C) (C) and (D) (D) (B) and (C)
(E) (A), (B) and (D)
5. Which of the following is not a stem modification?
(A) Tendrils of cucumber (B) Flattened structures of Opuntia
(C) Pitcher of Nepenthes (D) Thorns of citrus
6. Match the vegetative propagules listed under column I with the plants given under column II choose the appropriate
option from the given choices.
Column I Column II
A. Rhizome i. Agave
B. Offset ii. Bryophyllum
C. Sucker iii. Ginger
D. Leaf buds iv. Chrysanthemum
v. Eichhornia
(A) A-iii, B-v, C-iv, D-ii (B) A - iii, B - iv, C -i, D - ii
(C) A - ii, B - i, C - v, D - iv (D) A - iv, B - v, C - ii, D -iii