Androecium(male reproductive part)

biology ppt class 11 on androecium unit 1

1. INTRODUCTION WHAT IS A FLOWER The seed-bearing part of a plant, consisting of reproductive organs (stamens and carpels) that are typically surrounded by a brightly coloured corolla (petals) and a green calyx (sepals ). REPRODUCTIVE PARTS OF FLOWER Androecium gynoecium

2. ANDROECIUM(MALE REPRODUCTIVE PART) It is composed of stamens. Stamen consists of anther , filament and stalk. A nther U sually bilobed and each lobe has two chambers ,the pollen sacs where pollen grains are produced . Stamens Epipetalous:- attached to petals. Epiphyllous:-attached to perianth .eg:lily. Monoadelphous:-stamens united to one bunch or bundle.eg:china rose Diadelphous:-stamens united to two or more bundles. Eg:pea. Polyadelphous:-stamens united to two or more bundles .eg:citrus .

3. GYNOECIUM(FEMALE REPRODUCTIVE PART) It is composed of one or more carpels . It consists of three parts stigma ,style ,ovary. Ovary is enlarged basal part to which lies the elongated tube style. Ovary bears one or more ovules attached to the placenta . Apocarpous :- carpels are free.eg:-lotus and rose Syncarpous :-carpels are fused.eg:-mustard and tomato Stigma is usually at tip of the style it is receptive surface of pollen grain. Style connects ovary to stigma.

4. PLACENTATION Placentation: arrangement of ovules in ovary. Placentation are of 6 types:- Marginal :-placenta forms a ridge along the ventral suture of ovary and ovules are borne on this ridge forming two rows eg:pea Axile:-ovules attached to placenta in multilocular ovary eg: rose Parietal:-ovule develops on inner wall of ovary. Free central:-ovules borne on central axis, septa absent eg D ianthus Basal:-placenta develops at base of ovary, single ovule attached to it.eg sunflower .

5. FRUIT A characteristics feature of flowering plants Fruit formed without fertilization of ovary is parthenocarpic. Structure of fruit It consists of wall or pericarp which maybe dry or fleshy It is differentiated into outer epicarp , middle mesocarp and the inner mesocarp .

6. SEED What is seed?? The unit of reproduction of a flowering plant, capable of developing into another such plant. Structure of seed Outer most covering is a seed coat Seed coat has two layers the outer testa , inner tegmen. A scar on seed coat through which developing seeds are attached to fruit is hilum . S mall pore above hilium is micropyle. Radicle: the part of a plant embryo that develops into the primary root . Plumule:- the immature shoot or stem of an embryo plant

7. STRUCTURE OF DICOTYLEDONOUS SEED S eed coat consists of two cotyledons which contain food material and are fleshy and embryonal axis . Radicle and plumule are present at the end of embryonal axis . On basis of food storing tissue seeds are of two types:- Endosperm seed : -developing seed in which endosperm is present and develops as a result of double fertilization. Non-endospermous seed :-mature seeds in which endosperm is absent.eg bean , gram and pea

8. STRUCTURE OF MONOCOTYLEDENOUS SEED They are endospermic except orchids which are non-endospermic. Endosperm is bulky and stores food. Seed coat is membranous and fused with fruit wall

9. STRUCTURE Outer covering of endosperm separates the embryo by a proteinous layer call aleurone layer . The embryo is small and it is situated in depression at one end of endosperm. Embryo consists of large & shield shaped cotyledon known as scutellum. Embryo consists of short axis with plumule and radicle Plumule and radicle are enclosed in shealth called coleoptile and coleorhiza

10. Summing up Flower:- seed bearing part of plant. Androecium :-female reproductive w horl of a flower consists filaments,stalk,anther Gyonecium :- male reproductive part consists of anther style stigma Placentation :-arrangements of ovules in ovary. It is classified into parietal,marginal,axile ,free central, basal. Seed :-unit of reproduction Monocotyledonous seed :-consists of one cotyledon Dicotyledonous :- consists of 2 cotyledons