Aim: -To dissect given flower to study and display different whorls.
XII BIOLOGY PRACTICAL -5
Que
2 (Minor Experiment)…03 Marks
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Dissect
the given flower to display the floral whorls. Take a T. S. or V. S. of ovary to show number of chambers
(locules). Sketch and label the diagram.
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OR
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Make
a temporary preparation to show pollen germination. Draw neat and labelled
diagram of the same.
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OR
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Calculate
population density/ frequency of any one plant species by quadrat method.
Q2.
Dissect the given flower to display the floral whorls. Sketch a neat labelled
diagram of T.S. of Ovary (5 chambers).
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Display
of Floral whorls ……………1 Mark
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T.S.
of ovary Slide preparation ....1 Mark
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Diagram
of T.S. of ovary ……………1 Mark
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Total -……………………………………….3 Marks
Aim:
-To dissect given flower to study and display different whorls. Dissect ovary
to show number of chambers.
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Requirements: -Flower of Hibiscus, forceps,
razor blade, slides, cover slips, two needles, dissecting microscope, paper,
etc.
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Procedure:
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(1)
Take an open flower of Hibiscus or Brassica and observe the different floral
whorls, namely calyx,corolla, androecium and gynoecium
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(2)
Separate out each floral whorl carefully with the help of needles and forceps.
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(3)
Arrange the members of each whorl separately on a white paper or a glass slide.
(4) Count the members of each whorl. Note down their attachment with other members of the same whorl i.e., cohesion or their union with the other whorls i.e., adhesion.
- (5)
Observe the separated members under a dissecting microscrope.
- (6) Draw diagrams of the members of each whorl.
- ( 7) Take a transverse section of anther and ovary with the help of a blade. Mount the sections in a drop of glycerine.
- (8)
Observe the number of chambers in anther and ovary. Observe T.S. of anther
under a compound microscope and the T.S. of ovary under a dissecting
microscope.
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Observation of Hibiscus flower
- (1) Epicalyx :
- 5 to 8 free
bracteoles, green in colour
- (2) Calyx:
- Sepals-5,
gamosepalous, green in colour
- (3) Corolla:
- Petals-5,
polypetalous, large, showy, red in colour.
- (4) Androecium:
- Stamens
many, monadelphous. Exerted filaments of stamens are fused to form a tubular
structure called' staminal tube. The staminal tube bears a number of reniform,
dorsifixed anthers.
- (5) Gynoecium:
- Pentacarpellary,
placentation-axile, style long capitate. syncarpous, ovary superior and
pentalocular, and passes through the staminal tube. Stigma five,
- Family : Brassicaceae
- Flower : Complete,
pedicellate, ebractate, hermaphrodite,actinomorphic,
tetramerous, hypogynous, cyclic.
- Calyx : Sepals-4, polysepalous, petaloid, green.
- Corolla :
Petals-4, polypetalous, cruciform, valvate aestivation. Androecium : Stamens-6
in two whorls (2 + 4), polyandrous, tetradynamous,2
outer short and 4 inner long, dithecous.
- Gynoecium : Bicarpellary, syncarpous, style short, stigma bilobed.
- (1)Define flower:
- Ans: A
flower is a highly modified, condensed, reproductive shoot in Angiosperms.
- (2) What is the function of flower?
- Ans:
A flower is the reproductive organ in plants. It possesses male and female sex
organ for sexual reproduction.
- (3) Which are the essential floral whorls?And why?
- Ans: Essential
floral whorls include Androecium and Gynoecium. They produce the male and
female gametophytes for sexual reproduction.
- (4) What is the difference between polypetalous and gamopetalous corolla?
- Ans: A
corolla is said to be polypetalous when the petals are free. It is gamopetalous
when the petals are united/fused.
- (5) Which are the different parts of stamen and carpel?
- Ans: A
stamen consists of two parts - filament and anther. A carpel consists of three
parts - ovary, style and stigma.
- MULTIPLE CHOICE QUESTIONS
- (1) The type of placentation seen in Hibiscus ovary is ____________ .
- (a) parietal
- (b) marginal
- (c) free central
- (d) axile
- (2) The anthers in Hibiscus are ____________.
- (a) monothecous
- (b) monothecous basifixed
- (c) bithecous basifixed
- (d) bithecous dorsifixed
- (3) Hibiscus shows protandrous condition. It will favour ____________ .
- (a) self pollination
- (b) cross pollination
- (c) vegetative reproduction
- (d) autogamy
- (4) In Hibiscus, aestivation of calyx is ________ and of corolla is _________ .
- (a (a) contorted and valvate
- (b) twisted and valvate
- (c) valvate and twisted
- (d) vexillary and valvate
- (3) Hibiscus shows protandrous condition. It will favour ____________ .
- (a) self pollination (b) cross pollination
- (c) vegetative reproduction (d) autogamy
- (4) In Hibiscus, aestivation of calyx is ________ and of corolla is _________ .
- (a) contorted and valvate (b) twisted and valvate
- (c) valvate and twisted (d) vexillary and valvate
- (5) Hibiscus is a hypogynous flower because its ovary is ____________ .
- (a) inferior (b) semi-superior
- (c) superior (d) semi-inferior
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Ans: (1) - (d), (2)
- (b), (3) - (b), (4) - (c), (5) - (c).