Types of asexual reproduction Binary fission – Amoeba, paramecium, Euglena

5. Asexual reproduction is also called agamogenesis or agamogeny. The production of offspring by a single parent without formation and fusion of gametes is called asexual reproduction. The individuals produced by asexual reproduction are identical and exact copies of their parents. Clone – A group of genetically and morphologically identical offspring's produced from a single parent is called Clone

6. Types of asexual reproduction Binary fission – Amoeba, paramecium, Euglena Multiple fission – Plasmodium, Amoeba, Monocysts[ protozoans] Budding – daughter organisms is formed from small projections , the bud arising from the parent body. Exogenous budding- bud grows externally on the surface of the parent body Eg: Hydra, Yeast Endogenous budding – buds are formed with in the parent body. They are called Gemmules . They consist of small group of cells called archeocytes enclosed by a protective coat. During favorable conditions archeocytes comes out and grow into new individual Eg: Sponges 4. Zoospores – special motile cells- Kingom Fungi and algae [ Chlamydomonas] 5. Conidia – non – motile exogenously produced structures produced on special hyphae called conidiophores eg: Penecillium, Aspergillus No organism is immortal except unicellular organisms which multiply by binary fission. Amoeba , bacteria In the process of binary fission original cells become daughter cells. Therefore natural death is absent

7. Vegetative Propagation- Regeneration of new plants from vegetative parts Runner – oxalis Rhizome – ginger, Banana Tuber – Potato Sucker – Mint Stolon – Strawberry Bulb – onion, garlic Offset – Water Hyacinth[ terror of Bengal-standing water- drains oxygen- death of fishes- Eichhornia] Leaf buds – Bryophyllum Bulbil –fleshy buds which develop into new plants after falling on the ground- Agave [ Century Plant] Vegetative propagules – parts of plants that serve as means of vegetative propagation are called vegetative propagules.

8. Importance of Vegetative Propagation Only known methods of reproduction in plants like Banana, seedless grapes and oranges, rose and jasmine that have lost their ability to produce seeds by sexual reproduction Plants which produce small quantity of seeds like Bermuda grass or doob grass- propagated vegetatively. More rapid, easier and less expensive method of multiplying plants with either poor seed viability or prolonged seed dormancy Help to introduce plants in new areas where seed germination fails to produce plants Good qualities of a race or variety can be preserved indefinitely.

10. Characteristics of sexual reproduction [Sexual reproduction is also called amphimixis or amphigony] Usually biparental Gametes are always formed. Fertilization takes place It involves both mitosis and meiosis Daughter organisms genetically differ from the parents Multiplication is not so rapid as in asexual reproduction.

13. Similarities in Pattern of Sexual reproduction All organisms even though differ in external morphology, internal structure and physiology, they show similar pattern of sexual reproduction Juvenile / Vegetative phase It is the period of growth between birth of an individual upto reproductive maturity [ vegetative phase in plants] Reproductive phase Plants – onset of flowering In some plants flowering occurs more than once during their life span. In such plants, the inter – flowering period is called reproductively mature phase. In animals the juvenile phase is followed by morphological and physiological changes prior to active reproductive behavior such as development of secondary sexual characters and reproductive organs. This is called puberty in humans

14. There are two types of Flowering Plants Monocarpic Plants Flower only once in their life. After flowering they produce fruits and die All annuals, biennials and few perinnials Polycarpic plants flower repeatedly at different intervals every year eg: Perennials

19. Oestrus cycle In non – primate animals [ animals having small brain] the cyclic changes during reproductive phase is called oestrus cycle. It consist of A short period of heat or oestrus during which the female receives the male for copulation. A period of rest or anoestrus during which the females becomes passive and does not receive the male Eg: cows, sheep, rats, deers, dogs, tiger etc The seasonal breeding animals spend most of the year in anoestrus period. Menstrual cycle In primate animals the cyclic changes during reproductive phase is called menstrual cycle. Menustration is the bleeding from the uterus of adult females at intervals of one lunar month.[ 28 days on an average in female humans]

20. Differences Oestrus cycle Menstrual cycle It occurs in primate animals. It consist of menstrual phase, follicular phase and luteal phase Blood flows in the menstrual cycle. Sex urge does not increase during menstruation • It occurs in non – primate animals. • It consist of a short period oestrus or heat followed by a anoestrus or passive period. • Blood does not flow in oestrus cycle • Sex urge increased during oestrus period

21. Senescence It is the period between reproductive maturity and death of the organism It is characterized by gradual ceasation of functional activities and cellular breakdown leading to death of the organism. Difference between aging and senescence

22. Types of sexual reproduction- Syngamy and conjugation • Syngamy • It involves the complete and permanent fusion of male and female gametes • Based on morphology and physiology of fusing gamentes- • Isogamy - fusion of morphologically similar gametes which may differ in their physiology. Eg: chlamydomonas , Monocystis[ protozoan] • Anisogamy [ heterogamy]- fusion of gametes which differ in morphology or physiology- small gamete – microgamete-male gamete • large gametes – macrogametes – female gametes – Eg: higher • invertebrates and all vertebrates including human • c. Oogamy – fusion of large non motile female gamete and a small motile male gamete – Eg” volvox, Fucus [algae ] and other plants • d. Hologamy – fusion of two individual organisms- organisms act as gametes – Eg: yeast

23. Conjugation It involves union of two parents for short time so as to exchange their male pronuclei to form synkaryon and then separate to form daughter individuals eg: paramecium spirogyra endogamy – involves the fusion of male and female gametes of the same parents- Eg: tapeworm exogamy – the fusion of gametes produced by two different parents – Eg: earthworm, leeches, cockroach, frog