CYCAS - Madan Academy

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CYCAS

SYSTEMATIC POSITION ::

Kingdom → Plantae

Sub kingdom → Embryophyta

Division → Tracheophyta

Class → Gymnospermae

Subclass → Cycadophyta

Order → Cycadales

Family → Cycadaceae

Genus → Cycas

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Common name : Sago palm or palm fern.

Cycas is the most widely distributed genus of the order Cycadales. There are about 20 species which

occur in wild state in China, Japan, Australia, Africa, Nepal, Bangladesh, Burma and India. Four species

of Cycas – C. circinalis, C. pectinata, C. rumphii and C. beddomei – occur in natural state in India,

chiefly in Assam, Orissa, Meghalaya, Andaman and Nicobar Islands, Karnataka and Tamil Nadu. C.

revoluta and C. siamensis are widely grown in gardens.

C. rumphii – This species occurs in Andaman and Nicobar Islands.

ECONOMIC IMPORTANCE ::

A tincture prepared from the seeds of C. revoluta is used to relieve headache, giddiness and sore throat.

Leaves of C. revoluta are rich in nitrogen and they are used as green manure for rice, sweet potato and

sugarcane.

The starch of stem cortex & pith (usually) of C. revoluta is utilized for the production of sago

SPOROPHYTE ::

[I] External morphology :

Cycas is an evergreen slow-growing palm-like small tree with an average height of 1.5-3m. It is

commonly found in xerophytic habitats. It also grows well under cultivation in gardens. The

sporophytic plant body is differentiated into roots, stem and leaves.

1. Root : There are two types of roots in Cycas :

(i) Normal tap roots (ii) Coralloid roots.


(a) Normal tap roots : These roots are positively geotropic and their main function is anchorage and

absorption of water and mineral nutrients.

(b) Coralloid roots : These are speciallised apogeotropic roots which grow on the surface of the soil.

They are repeatedly dichotomously branched and appear as coralline masses. They are more

frequent on young plants. The coralloid roots possess lenticels, which help in respiration.

2. Stem : In mature plants, the stem becomes thick, columnar and woody. It is covered with persistent

and woody leaf bases.


The stem is usually unbranched.

3. Leaves : Cycas has dimorphic leaves : (i) Foliage or Assimilatory leaves and (ii) Scale leaves.

(i) Foliage or Assimilatory leaves : Large, pinnately compound foliage leaves form a crown at the

top of stem. The leaflet has a single mid vein, lateral veins are absent. Young leaves covered with

ramenta.

• Circinate vernation is found in young leaf let.

(ii) Scale leaves : The scale are small, rough, dry and triangular. They are thickly covered with

ramenta. They are incapable of carbon assimilation and their main function is to protect apical

meristem and other aerial parts.

• The foliage and scale are arranged in close alternate whorls at the stem. Usually a single crown

of leaves is formed in a year.

[II] Internal Anatomy :


(a) Internal Structure of Normal Tap Root :

Vascular tissue forms a central diarch stele. The xylem is exarch and tracheids of the protoxylem have

spiral thickenings and metaxylem tracheids have sclariform thickenings.

The mature normal root shows secondary growth.

(b) Internal structure of Coralloid root : Coralloid roots'cortex is differentiated in to three distinct

regions.

Middle cortex ⎯→ It has algal zone. The algal zone consists of a single layer of lossely connected thin

walled and radially elongated cells. In the algal zone blue-green algae, such as Anabaena cycadae,

Nostoc punctiforme and Oscillatoria spp. occur which live symbiotically. These help in nitrogen fixation.

Pericycle is present inside inner cortex.

Vascular Bundle : coralloid roots are triarch and exarch. Root

hair and root cap absent in coralloid roots

(c) Internal structure of Stem : Its internal structure is similar to

that of a dicotyledonous stem.

Epidermis is usually discontinous due to the presence of

persistent leaf bases.


Cortex composed of parenchymatous cells, rich in starch grains.

The cortex is also traversed by several mucilagenous canals and

many leaf traces.

Endodermis and pericycle both are indistinct.

There are several vascular bundles arranged in a ring forming an ectophloic siphonostele.

The vascular bundles are conjoint, collateral, endarch

and open.

In a transverse section of stem, numerous leaf traces can

be seen in the cortical region. They are vascular strands

which supply the leaves.

Each leaf receives four leaf traces. (Two direct & Two

girdle traces)


There is a parenchymatous pith in the centre of stem. The pith cells are rich in starch and several pith

cells also contain tannin and mucilagenous substances.

The stem of Cycas shows normal secondary growth in early stages, similar to that of dicotyledonous

stem.

Note : Young stem of Cycas which is monoxylic earlier becomes polyxylic later on.

(d) Internal structure of leaf : -

(i) Rachis : - In a transverse section rachis is circular in outline. It has two rows of leaflets inserted on

the adaxial side.

• Ground tissue containing mucus canals present below hypodermis.

• There are several vascular bundles in the

ground tissue and they are arranged in a

typical inverted omega-like arc.

• The vascular bundles are conjoint, collateral

and open, and each is surrounded by a single

layered bundle sheath.

• Xylem is diploxylic in V.B. i.e. centrifugal &

centripetal xylem present. Centrifugal xylem

is more at basal part of rachis while centripetal

xlyem is more towards tip.

(ii) Leaflet :.

• Upper and lower epidermis is present. stomata are present only at lower epidermis .

• Leaf mesophyll is modified in pallisade and spongy tissue.

• There are groups of tracheid-like cells on the lateral sides of the vascular xylem in the mid-rib

region. These cells have reticulate thickenings and bordered pits on their walls. They represent

transfusion tissue.

• In the wing region long colourless and transversely elongated parenchyma cells are present in

between palisade and spongy parenchyma. They represent secondary or accessory transfusion

tissue.

• Accessory transfusion tissue helps in lateral conduction of water and nutrients because lateral

veins are lacking in cycas.

• A single vascular bundle is present in the midrib region. The vascular bundle is conjoint

collateral, open and xlyem is diploxylic.

• It has a large and triangular centripetal xylem (Adaxial in position) and two small groups of

centrifugal xylem (Abaxial in position).

• A thin layer of cambium is present between the xylem and phloem.

REPRODUCTION ::

Cycas reproduces by vegetative and sexual means.

I. Vegetative reproduction :

• Vegetative propagation takes place by resting adventitious buds or bulbils. They develop in

the basal part of the stem from parenchymatous cells of the cortex, in the crevices between

persistent leaf bases.

• It is a common method of propagation in C.revoluta.. Bulbils formed on male plants give rise to

male plant and those developed on female plants form female plants.

• In C.circinalis, vegetative propagation takes place by suckers which develop from the roots.

They grow horizontally at the ground for some distance and then form new plants.

II. Sexual reproduction : -


• Species of Cycas are strictly dioecious.

1. Male strobilus : The strobilus (cone) develops at the apex

of the stem in between the crown of foliage leaves. In its development apical meristem of the

stem is utilised and as a result the future stem becomes sympodial.

• The male cone is shortly stalked, compact, oval or conical woody structure.It is 40-80 cm in

length, the largest among the plant kingdom.

• The microsporophyll is a woody, more or less

horizontally flattened and nearly triangular

structure. It is differentiated into a proximal

wedge-shaped fertile part which expands distally

from a narrow point of attachement and a distal

sterile part, tapering into an upcurved apophysis.

The upper (adaxial) surface of the fertile part of


MicropyleOuter fleshy layer

Middle stony layer

Inner fleshy layer

Pollen chamber

ArchegoniaNucellus

Female gametophyte or prothallus or endosperm

Vascular strands

L.S. of Cycas ovule

the microsporophyll is sterile, while on the lower (abaxial) surface there are 700-1000

microsporangia, arranged in definite groups, known as sori. (Singular - Sorus). Each

microsporangium is globular and sac like structure. The wall of microsporangium is trilayered.

Exothecium

Endothecium

Tapetum

• Tapetum is inner most and it covered sporogenous tissue

Types of development of microsporangium → Eusporangiate type.

Microsporogenesis : Microsporogenus cell ⎯⎯⎯ →⎯mitosis microsporemother cell ⎯⎯⎯ →⎯

meiosismicrospore

FEMALE REPRODUCTIVE STRUCTURE :: The megasporophylls of Cycas are not organised into cones and instead

they occur in close spirals in acropetal succession around the stem apex

of the female plant. New megasporophylls are produced every year like

the foliage leaves. The growth of the apical meristem of the female plants

is monopodial, the axis countinues to grow as it produced foliage leaves

and megasporophylls.

The megasporophylls are considered to be modified leaves. They are flat

and dorsiventral structures, measuring 15-30 cm in length. A

megasporophyll is differentiated into a basal stalk and an upper pinnate

lamina. Ovules are formed on the lateral sides of the stalk.

Largest ovule in plant kingdom is present in Cycas thaursai.

STRUCTURE OF OVULE :

The ovule of Cycas is orthotropous and unitegmic. It is sessile or shortly, stalked and largest in the

plant kingdom, about 6 cm in length and 4 cm in diameter. The ovule consists of a large nucellus

surrounded by a single integument. The integument remains fused with the body of the ovule except at

the apex of the nucellus, where it forms a nucellar beak and micropyle.

The integument is very thick and is differentiated into

three distinct layers – the outer and inner layers are

fleshy, whereas the middle layer is hard and stony. The

inner fleshy layer remains fused with the nucellus and it

is short-lived. Mucilage canals and tannin cells are

frequently present in the integument. Some cells of the

nucellar beak dissolve to form a pollen chamber that

lies in the central region of the beak. The young ovule is

green and is covered by minute multicellular hairs. At

maturity it becomes red or orange in colour and hairs

disappear.

The ovule is supplied by three vascular strands from

megasporophyll.

GAMETOPHYTE ::

Cycas is heterosporous, it produces two types of spores – microspores and megaspores. The

microspore develops into male gemetophyte and the megaspore in female gametophyte.

A. Male gametophyte :

The male gametophyte develops partially inside the micro sporangium before pollination and partially

within the pollen chamber of the ovule after pollination.

1. Development of male gametophyte before polination : - The development of the male

gametophyte before pollination takes place inside the microsporangium. The microspore divides

by a transverse wall in to two unequal cells, a small prothallial cell and a large antherdial cell. The

prothallial cell does not divide further. The antheridial cell divides to form a small generative cell

(adjacent to the prothallial cell) and a large tube cell. Thus the microspore becomes 3-celled. The

dispersal of microspores takes place at the 3-celled stage. Further development occurs in the

pollen chamber of the ovule after pollination.

2. Pollination : The 3-celled microspores are shed in the air after the dehiscence of the sporangium.

They are very light in weight and are carried by air currents.

• In synchronization with the time of dispersal of the microspores, some cells of the nucellar beak

disorganise to form a viscous fluid. This fluid oozes out from the micropyle in the form of a pollen

drop. Some of the microspores, carrieds by air current, are entangled in the pollen drop. As the

pollen drop dries up, the microspores are sucked into the pollen chamber through the micropylar

canal. As the result of drying of the viscous fluid, the micropylar canal of the pollinated ovules is

plugged.

2. Development of male gametophyte after pollination : Further development of the 3-celled male

gametophyte takes place within a week of pollination in the pollen chamber of the ovule. The

generative cell divides to form a stalk cell and a body cell, about the same time, the exine ruptures

and the intine protrudes out in the form of a pollen tube. The pollen tube penetrates the nucellar

tissue and grows towards the female gametophyte. In Cycas, the pollen tube is haustorial in

nature.


• The stalk cell does not divide, whereas the body cell divides to form two male gametes

(antherozoids) just before fertilization. (Mature male gametophyte of Cycas is 5-celled) The

antherozoids swim freely in the cytoplasm of the pollen tube. There is an interval of about four

months between the pollination and fertilization.

• The male gametes are naked, top-shaped structures, measuring 180-210 µm and multi ciliated/

multiflagellated.

Microspore

Prothellial cell

Antheridial cell

Generative cell

Tube cell

Body cell

Stalk cell

Male gamete

Male gamete


B. Development of Female Gametophyte :

Four megaspore are formed by meiotic division in megaspore mother cell. Megaspore mother cell is

originated from nucellus. Out of these four megaspore, three megaspore towards micropyle end

degenerate and only one remain functional. Free nuclear division occur in functional megaspore. Cell

wall formation occur and multicellular female gametophyte or endosperm is formed.

Archegonia are formed from archegonial initial cell which is present toward micropyle.

The mature archegonia consists of 2(generally)-4 neck cells and an egg. The venter is surrounded by a

nutritive jacket of cells formed by the gametophyte cells. This jacket is called archegonial jacket. Neck

canal cells are absent.

Note : - The number of archegonia in an ovule varies in different species of cycas, for example, 3-6 in

C. rumphii, 3-8in C.circinalis and 2-8 in C.revoluta.

Different stages of development of female gametophyte

[III] Fertilization – Zoodiosiphogamous type

Embryo development : Meroblastic and endoscopic

The Cycas proembryo differentiated into three regions : (i) the uppermost haustorial region at the

micropylar end, (ii) the middle suspensor region, and (ii) the basal embryonal region.

The cells of the haustorial region absorb nutrients from the micropylar end and provide them to the

developing embryo.

The cells of the suspensor region are elongated and much coiled. They push the embryo deep into the

female gametophyte (endosperm).

The embryonal region forms the main part of the embryo. The embryo takes about one year for its

complete development.

Two cotyledon are present in embryo of cycas.

A-G Cycas : Stages in the development of embryo

SEED :

The ovule is transformed into seed after fertilization. The inner fleshy layer of the ovule wall and the

major part of the nucellus are consumed in providing nourishment to the developing embryo. Thus both

these parts persist in the seed in the form of a thin layer.

The mature seed is red, orange or dark brown in colour. It is surrounded by a fleshy seed coat formed by

the three layers of the integument of the ovule. The outer fleshy layer of the integument forms

sacrotesta and the middle stony layer sclerotesta, while the inner layer remains thin and papery. The

seed coat has a sweet taste and pleasant odour. These provide attraction to birds and animals which help

in dispersal of seeds. There is a straight embryo with two unequal cotyledons inside the seed coat.

The seed of Cycas represents three generation. The seed coat, formed by the integument of the ovule,

represents the first sporophytic stage, the endosperm is the gametophyte stage and the embryo is the

next (new) sporophytic stage.

Germination of seed :

The seed germinates without undergoing any rest period. It remains viable only for few months. The

germination is hypogeal.

Species of Cycas No. of ovules in a megasporophyll

Cycas circinalis 12

Cycas revoluta 2 – 4

Cycas pectinata 4 – 6

Cycas rumphii 6 – 10

Cycas siamensis two

• Age of Cycads ⎯→ Triassic period of mesozoic era

• Height of Cycas media ⎯→ 20 meters

• In Cycas, the radicle is enclosed in a pod-like hard covering known as Coleorrhiza.

• Multiseriate bordered pits are present in Cycas tracheids.

• Two embryo are present in seed of cycas circinalis which are formed through two fertilized

archegonia.

Alternation of generation :

CYCAS EXERCISE

Q.1 Female cone is absent in which

gymnosperm :

(1) Cycas (2) Pinus

(3) Ephedra (4) None of these

Q.2 Ciliated male gametes are found in :

(1) Cycas (2) Ginkgo

(3) Pinus (4) Both (1) and (2)

Q.3 'Sago palm' is :

(1) Cycas revoluta (2) C. circinalis

(3) C. rumphii (4) Pinus


Q.4 How many species of Cycas are found in

India :

(1) 20 (2) 4 (3) 2 (4) 1

Q.5 How many kinds of leaves are found in

Cycas :

(1) 3 (2) 2 (3) 1 (4) 0

Q.6 Cycas trunk is covered with :

(1) Leaves (2) Leaf bases

(3) Scale leaves (4) Both (1) and (2)

Q.7 Inverted 'Omega' () shaped arrangement

of vascular bundles are found in :

(1) Cycas leaf (2) Cycas rachis

(3) Cycas stem (4) Cycas root

Q.8 Transfusion tissue is found in :

(1) Cycas leaf (2) Cycas leaflet

(3) Cycas petiole (4) Cycas root

Q.9 Cycas is :

(1) Monoecious (2) Dioecious

(3) Sterile (4) None of these

Q.10 Pollen grains are shed at ......... celled stage

in Cycas :

(1) 4 (2) 3 (3) 2 (4) 1

Q.11 The number of prothallial cells in male

gametophyte of Cycas is :

(1) 1 (2) 2 (3) 3 (4) 0

Q.12 Cycas ovule is :

(1) Orthotropous and unitegmic

(2) Orthotropous and bitegmic

(3) Anatropous and unitegmic

(4) None of the above

Q.13 How many archegonia develop on one

gametophyte of Cycas :

(1) 1 (2) 2

(3) 1 - 5 (4) 3 - 6

Q.14 Male gametes are largest and visible to

naked eyes in :

(1) Cycas (2) Pinus

(3) Gnetum (4) Ginkgo

Q.15 Germination of Cycas seed is :


(1) Epigeal (2) Hypogeal

(3) Both (1) and (2) (4) None of these

Q.16 The number of neck canal cells in the

archegonium of Cycas is/are :

(1) 2 (2) 4 (3) 6 (4) 0

Q.17 The number of cotyledons in seed of Cycas

is/are :

(1) 1 (2) 2

(3) Many (4) All of these

Q.18 Cycas plant is like ............ in appearance :

(1) Mango (2) Wheat

(3) Palm (4) Ficus

Q.19 Leaves in Cycas show :

(1) Hydrophytic characters

(2) Xerophytic characters

(3) Mesophytic characters

(4) Lithophytic characters

Q.20 The coralloid roots of Cycas have an algal

zone and the alga present in this zone is



(1) Ulothrix (2) Anabaena

(3) Nostoc (4) 2 and 3 both

Q.21 The neck canal cells are absent in the

archegonia of :

(1) Cycas (2) Bryophytes

(3) Funaria (4) Pteridophytes

Q.22 Stem of Cycas contains :

(1) Pycnoxylic wood (2) Manoxylic wood

(3) Heart wood (4) Porous wood

Q.23 Cycas has an embryo with two cotyledons

yet it is not classified as dicotyledonous

plant because :

(1) It has compound leaves

(2) It bears megasporophylls

(3) It looks like a palm tree

(4) Its ovules are naked

Q.24 Number of ovules present on

megasporophyll of Cycas is :

(1) Only one (2) One pair

(3) 1-6 pairs (4) Absent

Q.25 Multiciliate male gametes (spermatozoids)

are found in :

(1) Angiosperms (2) Cycas

(3) Ulothrix (4) Funaria

Q.26 Cycas is a gymnosperm because

(1) It form seeds

(2) It bear pollen grains

(3) It lacks ovary but has exposed ovules

(4) Its xylem consists of tracheids

Q.27 Which of the following is not the

characteristic feature of Cycas :

(1) Naked ovules

(2) Circinate vernation

(3) Vessels in xylem

(4) Girdling leaf trac

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Q.28 In the plants of Cycas, the male cone lacks :

(1) Microspore (2) Microsporophyll

(3) Microsporangium (4) Nucellus

Q.29 The girdle leaf traces in Cycas go to leaves :

(1) After making a semi-circle

(2) After making a complete circle

(3) After making two circle


Q.30 Polyembryony seen in Cycas is :

(1) Potential true polyembryony

(2) Potential true polyembryony and cleavage

polyembryony

(3) Adventive polyembryony

(4) All of the above

Q.31 Each leaf of Cycas is supplied by :

(1) Two direct traces and two girdle traces

(2) A number of direct traces and two girdle

traces

(3) A number of direct traces and a number

of girdle traces

(4) Two direct traces and a number of

girdle traces

Q.32 The secondary growth in stem of Cycas is

brought about by :

(1) Persistent cambium

(2) Short lived cambium

(3) Number of cambia produced in succession

(4) Isolated strips of cambium

Q.33 In which of the following, sexual

reproduction is possible without water :

(1) Ulothrix (2) Funaria

(3) Dryopteris (4) Cycas

Q.34 The tracheids of Cycas have :

(1) Uniseriate bordered pits

(2) Biseriate bordered pits

(3) Multiseriate bordered pits

(4) No bordered pits

Q.35 The neck cells in the archegonium of Cycas

are :

(1) One (2) Two

(3) Eight (4) Six

Q.36 The leaves of Cycas are :

(1) Unipinnately compound with parallel

venation


(2) Unipinnately compounds with unicostate

reticulate venation

(3) Unipinnately compounds with multicostate

reticulate venation

(4) Unipinnately compounds with no

venation

Q.37 Which is absent in coralloid roots of Cycas :

(1) Root hair and casparian band in

endodermis

(2) Root cap and casparian band in

endodermis

(3) Both root hair and root cap


Q.38 Which species of Cycas is having largest

male cones :

(1) Cycas revoluta (2) C. rumphii

(3) C. circinalis (4) C. beddomei

Q.39 Male and female Cycas plants show which

type of growth :

(1) Monopodial in both

(2) Sympodial in both

(3) Monopodial in male and sympodial in

female plant

(4) Sympodial in male and monopodial in

female plant

Q.40 A single microsporophyll in Cycas revoluta

is having about ........ sporangia :

(1) 1000 (2) 2000

(3) 100-300 (4) 400-500

Q.41 Seeds of Cycas are dispersed by :

(1) Wind (2) Birds

(3) Water (4) Insects

Q.42 Radicle (embryonic root) is covered by a

hard podlike covering 'coleorrhiza' in :

(1) Cycas (2) Pinus

(3) Both (1) and (2) (4) None of these

Q.43 In Andaman and Nicobar islands, common

species of Cycas is :

(1) C. circinalis (2) C. revoluta

(3) C. beddomei (4) C. rumphii

Q.44 During pollination, pollen grains in Cycas

are trapped by :

(1) Malic acid drop

(2) Pseudostigma

(3) Stigma

(4) Viscous Fluid in pollen chamber


Q.45 From the pith of stem of Cycas revoluta

"sago" is obtained which is used as food

article for a patient with stomach disorders

because :

(1) It is much tastier

(2) Its nutritive value is very high

(3) It is having less amount of starch and

easily digestable

(4) It is a cheap food article

Q.46 The main character of gymnospermic plant

is :

(1) Presence of xylem

(2) Presence of circinate vernation

(3) Presence of traces of leaves

(4) Presence of naked exposed ovules

Q.47 Largest ovule is found in :

(1) Cycas (2) Pinus

(3) Taxus (4) Watermelon

Q.48 Largest sperms in the plant world are found

in :

(1) Thuja (2) Pinus

(3) Banyan (4) Cycas

Q.49 Which of the following statements about

Cycas is incorrect ?

(1) Its coralloid roots contain some blue-

green algae

(2) It does not have a well organized female

flower

(3) It has circinate vernation

(4) Its Xylem is mainly composed of xylem

vessels

Q.50 Male cone of Cycas consists of :

(1) Megasporophylls (2) Microsporophylls


(3) Archegonia (4) None of these

Q.51 In which portion of Cycas, diploxylic

vascular bundle are found :

(1) Root (2) Stem

(3) Leaflet (4) Rachis and leaflet

Q.52 Which of the following is correct regarding

Cycas :

(1) The same sporophyll bears microsporangia

and ovules

(2) A single cone consists of both mega and

microsporophylls

(3) Male strobilus and megasporophylls

occur on the same plant

(4) Male strobilus and megasporophylls on

separate plants


Q.53 In Cycas, male gamets are produced in the

pollen tube by the division of which of the

following cells :

(1) Body cell (2) Stalk cell

(3) Tube cell (4) Prothallial cell

Q.54 Male gametes of cycas are :

(1) Rounded and nonciliate

(2) Sickle – shaped biflagellate

(3) Boat – shaped nonciliate

(4) Large, top-like, spirally twisted with cilia

Q.55 Vascular bundles of Cycas stem are :

(1) Conjoint, collateral and closed

(2) Conjoint, collateral and open

(3) Conjoint, bicollateral and open

(4) Conjoint, bicollateral and closed

Q.56 Naked seeds occur in :

(1) Pteris/Pteridophytes

(2) Cycas/Gymnosperms

(3) Funaria/Bryophytes

(4) Maize/Angiosperms

Q.57 Cycas resembles angiosperms in having :

(1) Circinate venation in leaves

(2) Vessels

(3) Motile sperms

(4) Ovules

Q.58 Vegetative reproduction in Cycas occurs by :

(1) Scale leaves (2) Bulbils

(3) Sporophylls (4) Fragmentation

Q.59 Cycas occurs commonly in :

(1) South America (2) North America

(3) South East Asia (4) Europe

Q.60 Algal zone is characteristic of :

(1) Coralloid root of Cycas

(2) Normal root of Cycas

(3) Normal root of Pinus

(4) Mycorrhizal root of Pinus

Q.61 Microsporangia of Cycas occur over

microsporophyll :

(1) Adaxially (2) Abaxially

(3) Laterally (4) Marginally

Q.62 Sago is obtained from :

(1) Cycas (2) Cedrus

(3) Pinus (4) Taxus

Q.63 Megasporophyll of Cycas is homologous to :

(1) Carpel (2) Stamen

(3) Coralloid root (4) Sepal


Q.64 What is the true about leaves of cycas-

(1) Palmate and Pinnate foliage leaves

(2) Brown scales and Pinnate green foliage

leaves

(3) Oblong and long leaves

(4) Green and scaly leaves


Q.65 Which one is living fossil :

(1) Pinus (2) Cycas

(3) Selaginella (4) Sphagnum

Q.66 If haploid number of chromosomes in a

gymnosperm is 12, the number of

chromosomes in its endosperm will be

(1) 12 (2) 24

(3) 36 (4) 64

Q.67 The number of neck canal cells in Cycas

(1) 2 (2) 4

(3) Nil (4) One with two nuclei

Q.68 Cycas is

(1) Monoecious and seed bearing

(2) Dioecious and seed bearing

(3) Monoecious and seedless

(4) Dioecious and seedless

Q.69 A prokaryotic autotrophic nitrogen fixing

symbiont is found in

(1) Pisum (2) Alnus

(3) Cycas (4) Cicer










Ques. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Ans. 1 4 1 2 2 2 2 2 2 2 1 1 4 1 2

Ques. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Ans. 4 2 3 2 4 1 2 4 3 2 3 3 4 1 1

Ques. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

Ans. 1 3 4 3 2 4 3 3 4 1 2 1 4 4 3

Ques. 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Ans. 4 1 4 4 2 4 4 1 4 2 2 4 2 3 1

Ques. 61 62 63 64 65 66 67 68 69

Ans. 2 1 1 2 2 1 3 2 3

CYCAS EXERCISE

Answer Key











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CYCAS - Madan Academy