Sexual Reproduction in Flowering Plants

Previous Years' CBSE Board Questions

1.2 Pre-fertilisation: Structures and Events

Stamen, Microsporangium and Pollen grain

MCQ

(AI 2019) U

group of compactly arranged homogenous mass of cells occupying the centre of a typical microsporangium in an anther is

1. sporogenous tissue (b) pollen sacs
2. microspore tetrads (d) spores.

(Term-I, 2021-22) R

The figures of the developmental stage of a microspore into a mature pollen grain are given below. Choose the option showing the correct labellings for (i), (ii), (iii) and (iv).

1. (iv)

1. (iii)

(2019)

1. (iii) (iii) (iv)
2. Generative Vegetative Male Vacuoles cell cell gametes
3. Vegetative Generative Vacuoles Male cell cell gametes
4. Generative Vegetative Nucleus Vacuoles cell cell
5. Vegetative Generative Vacuoles: Nucleus cell cell

(Term-I, 2021-22) R

V5A (1 mark)

1. Give an example of a plant which came into India as a contaminant and is a cause of pollen allergy.

(Al 2014)

SAI (2 marks)

1. (a) Explain the process of the development of a male gametophyte in an angiosperm.
2. Why is it called a male gametophyte? (2023)
3. In the T.S. of a mature anther given below, identify "a" and "b" and mention their functions.

A pollen grain in angiosperm at the time of

dehiscence from an anther could be 2-celled or

3-celled. Explain. How are the cells placed within the

pollen grain when shed at a 2-celled stage? (Al 2017)

1. Name the organic materials exine and intine of an angiosperm pollen grain are made up of. Explain the role of exine. (Delhi 2014)
2. Draw a diagram of a matured microspore of an angiosperm. Label its cellular components only.

(Foreign 2014) Ap

SA II (3 marks)

1. Draw a schematic transverse section of a mature anther of an angiosperm. Label its epidermis, middle layers, tapetum, endothecium, sporogenous tissue and the connective. (2020) Cr
2. Where are the following structures present in a male gametophyte of an angiosperm? Mention the function of each one of them.
3. Germ pore
4. Sporopollenin
5. Generative cell
6. (a) Name the organic material exine of the pollen grain is made up of. How is this material advantageous to pollen grain?
7. Still it is observed that it does not form a continuous layer around the pollen grain. Give reason.
8. How are 'pollen banks' useful? (Al 2016)
9. Why are angiosperm anthers called dithecous? Describe the structure of its microsporangium.

(Al 2014)

LA (5 marks)

1. (a) Where does microsporogenesis occur in an angiosperm? Describe the process of microsporogenesis.
2. Draw a labelled diagram of the two celled male gametophyte of an angiosperm. How is a three celled male gametophyte different from it?

(2020) Ap

Trace the development of a 2-celled pollen grain of an angiosperm within an anther. Draw a labelled diagram to substantiate your answer.

(2020)

1. (a) Name the specific part in the anther and the process responsible for the development of a male gametophyte in an angiosperm.

1. Draw a labelled diagram of a mature male gametophyte (3-celled) of an angiosperm. Write the functions of each labelled part.

(2020C)

1. (a) Draw a labelled diagram of the sectional view of microsporangium of an angiosperm.
2. Explain the development of male gametophyte in the microsporangium. (Delhi 2015C) R
3. (a) Describe the sequence of the process of microsporogenesis in angiosperms.
4. Draw a labelled diagram of a two celled final structure formed. (Delhi 2015C)

Pistil, Megasporangium and Embryo sac

MCO.

1. Figure (i) and figure (ii) given below are showing two stages of megasporogenesis in a typical angiosperm plant.
2. (X)

(Z) Fig. (ii)

Fig. (i)

Choose the option showing the correct ploidy of X, Y and Z in the table given below.

(ii)

1. (i) Synergids

X Y Z 2n n 2n 2n n n 2n 3n n 3n 2n n (d)

1. (b)
2. LA (5 marks)

(Term-I, 2021-22) An

1. Which one of the following is not found in a female gametophyte of an angiosperm?
2. Germ pore
3. Synergids
4. Filiform apparatus
5. Central cell

VSA (1 mark)

20.

These pictures show the gynoecium of (A) Papaver

and (B) Michelia flowers. Write the difference in the

structure of their ovaries.

(NCERT Exemplar, Delhi 2015C) (An)

21. State the function of filiform apparatus found in

mature embryo sac of an angiosperm.

(Foreign 2014)

SAI (2 marks)

A mature embryo sac in flowering plant may possess

7-cells, but 8-nuclei. Explain with the help of diagram

only. (NCERT Exemplar, Delhi 2017)

Gynoecium of a flower may be apocarpous or

syncarpous. Explain with the help of an example

each. (Al 2016) An

SA II (3 marks)

1. (a) Draw a L.S. of pistil showing pollen tube entering into the embryo sac. Label the following:
2. Nucellus
3. Antipodals
4. Synergids
5. Micropyle
6. Draw a labelled diagram of a typical anatropous ovule. (NCERT, Delhi 2014)
7. (i) Explain the monosporic development of embryo sac in the ovule of an angiosperm.
8. Draw a diagram of the mature embryo sac of an angiospermic ovule and label any four parts in it. (2023) R
9. Study the figures given below of the development of megaspore in an angiosperm and answer the questions that follow: