Chapter-2 Sexual Reproduction in Flowering Plants

Embryo sacs of some apomictic species appear normal but contain
diploid cells. Suggest a suitable explanation for the condition.

Draw the diagram of a microsporangium and label its wall layers. Write
briefly on the role of the endothecium.

With a neat, labelled diagram, describe the parts of a mature angiosperm
embryo sac. Mention the role of synergids.

What are the possible types of pollinations in chasmogamous flowers.
Give reasons.

Starting with the zygote, draw the diagrams of the different stages of
embryo development in a dicot.

The generative cell of a two-celled pollen divides in the pollen tube but
not in a three-celled pollen. Give reasons.

Why does the zygote begin to divide only after the division of Primary
endosperm cell (PEC)?

Are parthenocarpy and apomixis different phenomena? Discuss their
benefits.
Hint: Yes, they are different. Parthenocarpy leads to development of seedless
fruits. Apomixis leads to embryo development.

What is polyembryony and how can it be commercially exploited?

Does self incompatibility impose any restrictions on autogamy? Give
reasons and suggest the method of pollination in such plants.

Vivipary automatically limits the number of offsprings in a litter. How?

Given below are the events that are observed in an artificial hybridization
programme. Arrange them in the correct sequential order in which they
are followed in the hybridisation programme.
(a) Re-bagging (b) Selection of parents (c) Bagging (d) Dusting the pollen
on stigma (e) Emasculation (f) Collection of pollen from male parent.

List three strategies that a bisexual chasmogamous flower can evolve to
prevent self pollination (autogamy).

What is the function of the two male gametes produced by each pollen
grain in angiosperms.

How is pollination carried out in water plants?

Are pollination and fertilisation necessary in apomixis? Give reasons.

Which is the triploid tissue in a fertilised ovule? How is the triploid
condition achieved?

Draw the diagram of a mature embryo sac and show its 8-nucleate,
7-celled nature. Show the following parts: antipodals, synergids, egg,
central cell, polar nuclei.

Name the type of pollination in self-incompatible plants.

What is self-incompatibility?

Which are the three cells found in a pollen grain when it is shed at the
three celled stage?

Can an unfertilised, apomictic embryo sac give rise to a diploid embryo?
If yes, then how?

In case of polyembryony, if an embryo develops from the synergid and
another from the nucellus which is haploid and which is diploid?

Name the parts of pistil which develop into fruit and seeds.

Name the common function that cotyledons and nucellus perform.

Name the part of gynoecium that determines the compatible nature of
pollen grain.

Name the component cells of the ‘egg apparatus’ in an embryo sac.

Draw the embryo sac of a flowering plants and label :
(a) (i) Central Cell (ii) Chalazal end (iii) Synergids
(b) Name the cell that develops into embryo sac and explain how this cell
leads to formation of embryo sac.
(c) Mention the role played by various cells of embryo sac.
(d) Give the role of filiform apparatus.

Draw the embryo sac of a flowering plants and label :
(a) (i) Central Cell (ii) Chalazal end (iii) Synergids
(b) Name the cell that develops into embryo sac and explain how this cell
leads to formation of embryo sac.
(c) Mention the role played by various cells of embryo sac.
(d) Give the role of filiform apparatus.

Differentiate between microsporogenesis and megasporogenesis. What
type of cell division occurs during these events. Name the structure formed
at the end of these two events.

What will be the fate of following structures in the angiospermic plant?
Ovary wall, Ovule, zygote, outer integument Inner integument and primary
endosperm nucleus.

Continued self pollination lead to inbreeding depression. List three devices,
which flowering plant have developed to discourage self pollination?

Even though each pollen grain has two male gametes. Why are at least 10
pollen grains and not 5 pollen grains required to fertilise 10 ovules present
in a particular carpel?

Name the blank spaces a, b, c and d is the table given below :
Item What it represents in the plant
(i) Pericarp a
(ii) b Cotyledon in seeds of grass family
(iii) Embryonal axis c
(iv) d Remains of nucellus in a seed.

Name the parts A, B, C and D of the anatropous ovule (Figure 2) given
above.

Differentiate between geitonogamy and xenogamy.

Among the animal, insects particularly bees are the dominant pollinating
agents. List any four characteristic features of the insect pollinated flower.

Fruits generally develops from ovary, but in few species thalamus
contributes to fruit formation.
(a) Name the two categories of fruits.
(b) Give one example of each.

Fruits generally develops from ovary, but in few species thalamus
contributes to fruit formation.
(a) Name the two categories of fruits.
(b) Give one example of each.

Outer envelop of pollen grain made of a highly resistant substance. What
is that substance? At which particular point the substance is not present?

In angiospermic plant before formation of microspore sporogenous tissue
undergo cell division
(a) Name the type of cell division.
(b) What would be the ploidy of the cells of tetrad?

If the diploid number of chromosomes in an angiospermic plant is 16.
Mention number of chromosomes in the endosperm and antipodal cell

Arrange the following in correct developmental sequence :
Male gamete, Potential pollen mother cell, sporogenous tissue, Pollen
grains, Microspore tetrad.

In same species of Asteraceae and grasses, seed are formed without
fusion of gametes. Mention the scientific term for such form of reproduction.

Why are pollen grains produced in enormous quantity in Maize?

Pollen grains of water pollinated species have a special characteristics for
protection from water. What is that?

Give the scientific name of a plant which came to India as a contaminant
with imported wheat and causes pollen allergy.

In a young anther, a group of compactly arranged homogenous cells were
observed in the centre of each microsporangium. What is the name given
to these cells?

Explain the development of embryo in a dicotyledonous plant with neatly labeled
diagrams.

Explain the development of embryo in a dicotyledonous plant with neatly labeled
diagrams.

Give any three advantages of sexual incompatibility.

Enlist the advantages offered by seeds to angiosperms.

Describe the structure of a pollen grain.

What relationship exists between a species of moth and Yucca plant?

Which type of pollination ensures the arrival of genetically different pollen
grains to stigma?

Differentiate between chasmogamous and cleistogamous flowers

State the characteristics of insect pollinated flowers.

What is polyembryony?

Why do most zygotes develop after certain amount of embryo is formed?

Name one plant each where pollination occurs with the help of (1)
a) Water.
b) Bats

What is sporopollenin?

What do you understand by double fertilization?

Explain the formation of an embryo sac with diagrams.

Explain the structure of an anatropous ovule with a neat labeled diagram?

What is triple fusion? Where does it occur?

Explain the stages involved in the maturation of a microspore into a pollen grain.

Differentiate between microsporogenesis and megasporogenesis.

Differentiate between microsporogenesis and megasporogenesis.

State any one advantage and disadvantage of pollen grains to humans.

Why are cleistogamous flowers invariably autogamous?

How are the cells arranged in an embryo sac?

Why pollen grains can remain well preserved as fossils?

Describe the structure of a microsporangium with a neatly labeled diagram.

Why is emasculation done in the process of hybridization?

What is microsporogenesis?

Define parthenocarpy.

What is funiculus?

What kind of structures is formed at the end of microsporogenesis and
megasporogenesis?

i) Why is zygotes dominant for sometime in fertilized ovule.
ii) What is polyembryony? Give an example.
iii) In fruits, what is formed from following parts :-
a) Ovary wall b) Outer integument c) Inner integument d)
zygote
e) primary endosperm f) Ovary g) Nucellus

How dose pollination takes place in salivia. List any four adaptations
required for such type of pollination.

“Incompatibility is the natural barrier in fusion of gamete”. Justify this
statement.

List the advantages of pollination to angiospermic plants?

Draw a well labeled diagram of longitudinal section of pistil showing pollen
germination?

What is apomixis? What is its importance?

Name the part of plant producing seed & fruit after fertilization.

Why apple is called a false fruit. Which part of plant forms the fruit?

Name the part of an angiosperm flower in which development of male &
female gametophyte takes place.

Trace the events that would take place in flower from the time of Pollen grain
of species fall on stigma up To completion of fertilization.

Trace the development of megasporocyte into mature ovule.

Trace the development of megasporocyte into mature ovule.

i) Explain the structure of a maize grain with the help of a diagram
ii) Why cannot we use the term maize seeds for maize grains?

Mention two strategies evolved lay flowers to prevent self-pollination

Draw a labeled diagram of mature embryo sac & label the following
i) Egg cell ii) Antipodal cells iii) Synergids iv) Polar nuclei

What are cleistogamous flowers? Can cross – pollination occurs in
cleistogamous flowers. Give reason?

Why are pollen grains produced in enormous quantity in maize?

Why are pollen grains produced in enormous quantity in maize?

Give an example of Bat – Pollinated flower.

Which are the nuclei that fuse to form endosperm?

Describe the post-fertilization changes taking place in a flowering plant?

Describe the post-fertilization changes taking place in a flowering plant?

Trace the development of microsporocyte into mature pollen grains.

List any three differences between wind pollinated flower & insect –
pollinated flower.

Why is process of fertilization in flowering plants referred to as double
fertilization?

Draw a diagram of L.S. of an anatropous ovule of an Angiosperm & label the
following parts :-
(i) Nucellus (ii) Integument
(iii) Antipodal cells (iv) Secondary Nucleus.

Differentiate between Geitonogamy & Allogamy.

Mention the scientific term for the type of pollination which ensures Genetic
Recombination.

How many haploid nuclei and haploid cells are present in female
gametophyte of angiosperm?

Name the type of cross pollination in Vallisneria & Bougainvillea.

What is apomixis and what is its importance?

Explain the role of tapetum in the formation pollen-grain wall.

If one can induce parthenocarpy through the application of growth substances, which fruits would you select to induce parthenocarpy and why?

What is meant by emasculation? When and why does a plant breeder employ this technique?

Why is apple called a false fruit? Which part(s) of the flower forms the fruit?

Differentiate between:

(a) Hypocotyl and epicotyl;

(b) Coleoptile and coleorrhiza;

(c) Integument and testa;

(d) Perisperm and pericarp.

Why do you think the zygote is dormant for sometime in a fertilized ovule?

Why do you think the zygote is dormant for sometime in a fertilized ovule?

What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.

What is bagging technique? How is it useful in a plant breeding programme?

What is self-incompatibility? Why does self-pollination not lead to seed formation in self-incompatible species?

Mention two strategies evolved to prevent self-pollination in flowers.

What are chasmogamous flowers? Can cross-pollination occur in cleistogamous flowers? Give reasons for your answer.

With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.

What is meant by monosporic development of female gametophyte?

With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.

Arrange the following terms in the correct developmental sequence:

Pollen grain, sporogenous tissue, microspore tetrad, pollen mother cell, male gametes

Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events? Name the structures formed at the end of these two events.

Name the parts of an angiosperm flower in which development of male and female gametophyte take place.