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SEXUAL REPRODUCTION involves formation of male and female gamates, either by the same individual or different individuals of opposite sex.These gametes
Algae
-Algae are chlorophyll-bearing, simple, autotrophic and largely aquatic organisms.
-They occur in a variety of habitats like moist damp places .Some of them also occur in a-ssociation with fungi (lichen) and animals.
- They occur as unice
Reproduction: Reproduction is the biological process in which an individual gives rise to an offspring similar to itself.
Purpose of Reproduction:
Asexual Reproduction- Where offspring is produced by single parent with or without formation and fusion of gametes. e.g. Amoeba, Plan aria etc.
Her
DIFFERENT PHASES IN SEXUAL REPRODUCTION:
1. JUVENILE PHASE
It is a period of growth and
STAMEN
The stamens are modified leaves or microsporophylls concerned with the production of microspores or pollen grains. There are two part of stamen - the long an
Pre-fertilization Events:
These events of sexual reproduction are prior to the fusion (fertilization) of male and female gametes.
a) &nbs
Post Fertilization Events:
Events in sexual reproduction after the fertilization (formation of zygote) are called post fertilization events. These events may be d
3. Fragmentation:
It is that type of asexual reproduction in which the parental body breaks into two or more fragments either by wave action (e.g. sponges) or by
The flowering plants (angiosperms), also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies (derived characteristics). Etymolog
Heredity and Variation in Asexual Reproduction
If all offspring were exactly like their parents, there would be no science of genetics. Variations a
Pollen Grain
Pollen grains are male gametophyte - spherical in shape.
Microspore or pollen grain is haploid, uninucleate, minute spores
Embryo formation: Embryo develops at the micropylar end of the embryo sac where
the zygote is situated. Most of the zygotes divide only after certain am
Structure of Ovule:
Ovule is an integumented megasporangium found in sper- matophytes which develops into seed after fertilisation. An angiosperm o
Significance of cell cycles:
Mitosis and meiosis both involve cells division to make new cells. This makes them both vital processes for the existe
Kingdom Fungi:
i) They are heterotrophic.
ii) They are cosmopolitan and prefer to grow in warm and humid places.
Structure of Embryo Sac (Female Gametophyte):
In angiosperms, the female ga- metophyte is called embryo sac. Embryo sac is an oval multicellular haploid structure
Attemps to Classify
In this chapter, we will describe Plantae kingdom under Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms. At pres
Apomixis & Polyembryony
Apomixis is a special mechanism, to produce seeds without fertilization. It is a form of asexual repr
1. AUTOGAMY: Transfer of pollen grains from anther to stigma of the same flower.
REQUIREMENT:-
Fruit formation
The tissue of the ovary wall is stimulated to grow with development of seed. It produces a fruit wall or pericarp. In some cases th
Agents of Pollination:
1) Abiotic agents:
a) &
BRYOPHYTES
Bryophytes are divided into three classes: Hepaticae (Liverworts), Anthocerotae (Hor
Structure of Microsporangium
In transverse section a typical microsporangium appears near circular in outline. It is generally surrounded by four wall layers - the
Pistil:
Gynoecium represents the female component of a flower. It may consist of only one carpel (monocarpellary), two carpels (bicarpellary), or many carpels
POLLINATION: Transfer of pollen grains from anther to the stigma of a pistil is termed as pollination.
Double Fertilisation
The pollen tube releases the two male gametes into the cytoplasm of the synergid .One male gametes
fuses with egg cell
Endosperm formation
Seed
The fertilized ovule forms seed. The study of seed is called spermology.
The seeds are of two types:
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