Note 1|standard 12|Sexual reproduction in flowering plants|Introduction|short notes| NCERT| Biology

Sexual reproduction in flowering plants (New syllabus chapter 1 / old syllabus Chapter 2)

Introduction|Sexual reproduction in flowering plants|short notes| NCERT| standard 12| Biology

Note 1

Introduction

Plant kingdom classification

A. Algae

B. Bryophytes

C. Pteridophytes

D. Gymnosperms

E. Angiosperms

Only angiosperms have flowers, hence this chapter is totally for angiosperms.

Reproduction: Biological process by which organisms produce offspring

2 types:

1. Sexual reproduction: by fusion of gametes, mostly Biparental, also called as Amphimixis(because two types of gametes fuse)

2. Asexual reproduction: gametes may be produced or not, No fusion of gametes, always uniparental

Aids to sexual reproduction of flowering plants

a. Myriad (large collection) of flowers

b. Scents and perfume

c. Rich and bright colors

Human relationship with flowers

a. Aesthetic – looks good

b. Ornamental – for decoration

c. Social – for giving to someone

d. Religious – to offer to God

e. Cultural – garlands in wedding

f. Symbols of conveying feelings – love, affection, happiness, grief, mourning etc.

But flowers not only for human use and satisfaction.

Flower –

a. unit of sexual reproduction

b. site of sexual reproduction

c. Leads to end product of sexual reproduction i.e. fruits and seeds

Diagram of longitudinal section of flower

Flower – modified shoot (Stem + leaves)

Pedicel – floral stalk : which holds the flower to the plant

Recepticle – thalamus : flattened end of pedicel

                      Modified stem- contains 4 nodes

1. Sepal (modified leaf) – Calyx (protection of flower)

2. Petal – Corolla (attraction)

3. Stamen – Androecium (Anther + filament)(male reproductive part)

4. Pistil(carpel) – Gynoecium (ovary + style + stigma) (female reproductive part)

Calyx and Corolla – Accessory whorls of flowers – don’t take part in sexual reproduction directly, but support it

Androecium and Gynoecium – Essential whorls of flowers – produce male and female gametes

Q- Can you name the two parts in a flower in which the two most important units of sexual reproduction develop?

a. Androecium – anther – develop male gamete

b. Gynoecium – ovary – develop female gametes 

Q- Floriculture: branch of ornamental horticulture that deals with growing & marketing of flowers and ornamental plants as well as with flower arrangements.

Horticulture: deals with cultivation of garden crops, fruits and vegetables

Q- List at least five flowers of ornamental value that are commonly cultivated at homes and in gardens. 

1) Marigold

2) Jasmine

3) Rose

4) Tulips

5) Hibiscus 

Q- Find out the names of five more flowers that are used in social and cultural celebrations in families.

1) Marigold

2) Rose

3) Jasmine

4) Orchids

5) Lotus

Thank you for reading!

Happy learning! Stay motivated!

Manish Mevada

Urvi Bhanushali