Sexual Reproduction In Plants

STEPS … A T CY Pr ogr am _______________________________________________________________________________________ LECTURE NOTES – BIOLOGY

SEXUAL REPRODUCTION IN PLANTS Reproductive part of higher plants = FLOWER The flower contains sexual reproductive organs of a plant

Female sex organs

Male sex organs

Stamen

Carpel / Pistil

Pollen grains

Ovules

Produce

Produce

Male gametes

Female gametes

Fertilization

Seeds

new plants

Stamen Carpel (Pistil) Petal

Receptacle

Petal

flower stem

PARTS OF A FLOWER 1 STEPS____________________________________________________________ Get free chapterwise tests for Class Xth on www.tcyonline.com

STEPS … A T C Y P r og r am _______________________________________________________________________________________ LECTURE NOTES – BIOLOGY

POLLEN GRAINS

ANTHER

STAMEN

FILAMENT

Stamen- Male Reproductive Organ of a plant STIGMA

STYLE

OVARY OVULES Carpel /Pistil – Female Reproductive Organ of a plants. FORMATION OF SEEDS The seed of plant is formed when the male gamete present in problem grain unites with the femeale gamete present in the the ovule. It occurs in 2 steps. (1)

Pollination Self pollination cross pollination

(2)

Fertilization

Pollination: The transfer of pollen grains from the another of a stamen to the stigma of a carpel is called pollination. It is done by insects, birds, wind, water. Self Pollination:- When the poslen grains form the anther of a flower are transferred to the stigma of the same flower or another flower of same plant is called self pollination. Cross-Pollination:- When the pollen grains form the another of a flower on one plant are transferred to the stigma of a flower on another plant is called cross- pollination. In plants pollination is followed by Fertilization. 2 STEPS____________________________________________________________ Get free chapterwise tests for Class Xth on www.tcyonline.com

STEPS … A T CY Pr ogr am _______________________________________________________________________________________ LECTURE NOTES – BIOLOGY

Fertilization

(1) + (2) 2nd male gametes + 2 polar nucler

Pollen grain

Stigma of carpel

Endosperm nuclei TRIPLE FUSION = (3)

growth of pollin tube down words in style

Endosperm (food storage tissue of seed)

it reaches ovary embryo sac of ovule receives 2 male gametes thru micropyle.

Embryo sac contains 8 nucles 7 + nucleus

Embryo + Endospem = Seed

Ovule turns into seed

Ovary into fruit

1 female gamete

egg +

1st male gamete

Syngamy + Triple fusion = Double Fertilization

Syngamy

Pollen grain Stigma

Zygote

Style Pollen tube

Embryo

2 male gametes Micropyle Embryo sac 4 nuclei Ovule

Egg

Ovary

FERTILIZATION Parthenogenesis : The process of reproduction in which a new Organism takes birth of the female without fertilization is called parthenogenesis. It occurs in lizards, Honeybees.

STEPS____________________________________________________________ 3 Get free chapterwise tests for Class Xth on www.tcyonline.com