NCERT Exemplar solutions for Biology [English] Class 12 chapter 2 - Sexual Reproduction in Flowering Plants [Latest edition]

Among the terms listed below, those that of are not technically correct names for a floral whorl are:

1. Androecium
2. Carpel
3. Corolla
4. Sepal

Embryo sac is to ovule as ______ is to an anther.

In a typical complete, bisexual, and hypogynous flower the arrangement of floral whorls on the thalamus from the outermost to the innermost is ______.

A dicotyledonous plant bears flowers but never produces fruits and seeds. The most probable cause for the above situation is ______.

The outermost and innermost wall layers of microsporangium in an anther are respectively ______.

During microsporogenesis, meiosis occurs in ______.

From among the sets of terms given below, identify those that are associated with the gynoecium.

Starting from the innermost part, the correct sequence of parts in an ovule are ______.

From the statements given below choose the option that are true for a typical female gametophyte of a flowering plant.

1. It is 8-nucleate and 7-celled at maturity
2. It is free-nuclear during the development
3. It is situated inside the integument but outside the nucellus
4. It has an egg apparatus situated at the chalazal end

Autogamy can occur in a chasmogamous flower if ______.

Choose the correct statement from the following:

A particular species of plant produces light, non-sticky pollen in large numbers and its stigmas are long and feathery. These modifications facilitate pollination by ______.

From among the situations given below, choose the one that prevents both autogamy and geitonogamy.

In a fertilised embryo sac, the haploid, diploid, and triploid structures are ______.

In an embryo sac, the cells that degenerate after fertilisation are ______.

While planning for an artificial hybridization programme involving dioecious plants, which of the following steps would not be relevant ______.

In the embryos of a typical dicot and a grass, true homologous structures are ______.

The phenomenon observed in some plants wherein parts of the sexual apparatus are used for forming embryos without fertilization is called ______

In a flower, if the megaspore mother cell forms megaspores without undergoing meiosis and if one of the megaspores develops into an embryo sac, its nuclei would be ______.

The phenomenon wherein, the ovary develops into a fruit without fertilisation is called ______.

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

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

Name the common function that cotyledons and nucellus perform.

Complete the following flow chart

Indicate the stages where meiosis and mitosis occur (1, 2 or 3) in the flow chart.

In the diagram given below, show the path of a pollen tube from the pollen on the stigma into the embryo sac. Name the components of egg apparatus.

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

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

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

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

What is self-incompatibility?

Name the type of pollination in self-incompatible plants.

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.

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

Are pollination and fertilisation necessary in apomixis? Give reasons.

Identify the type of carpel with the help of diagrams given below:

How is pollination carried out in water plants?

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

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

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.

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

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

In the given diagram, write the names of parts shown with lines.

What is polyembryony and how can it be commercially exploited?

Are parthenocarpy and apomixis different phenomena? Discuss their benefits.

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

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

In the figure given below label the following parts: male gametes, egg cell, polar nuclei, synergid and pollen tube

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

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

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

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

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