1) Reproduction is the Reproduction :-process by which livingorganismsproduce new individuals ofthe same species. Reproduction isnecessary for the survivaland increasein the population of aspecies. If organisms do
importance of DNA copying during variation :-reproduction is importantfor maintaining the bodydesigns of differentorganisms to survive in theexisting environment. Butthe environment isconstantly changing due to
4) Types of reproduction There are two main :-of reproduction in living typesorganisms. They are asexualreproduction and sexualreproduction. Asexual reproduction :- isreproduction in which newindividuals are producedfrom a single parent.
i) Fission :- Fission is an asexualreproduction by which aunicellular organismdivides and forms two ormore new individuals.Fission is of two types.They are binary fission andmultiple fission.
ii) Budding :- In this method a budlike projection is formedon the body of the budorganism. The bud thendevelops into a new budindividual. It thenseparates from the parentand forms an independent
iii) Regeneration :- of In this method a partthe body if the organism ifcut or broken can developinto a new individual. Eg :-Hydra, Planaria, Star fishetc.
iv)Fragmentation :- In this method thebody of a simplemulticellular organismbreaks up into smallerpieces on maturation andeach fragment developsinto new individuals. Eg :- Spirogyra.
v) Spore In this method :- formationstructures called sporangiaproduce tiny cells calledspores. When the sporescome in contact with amoist surface, it developsinto new individuals.Eg :- Rhizopus , Mucor,
vi) Vegetative propagation :plants In this method new -are produced from thevegetative parts of the plantlike root, stem or leaf. Eg:-from roots – dhalia, sweetpotato,from stem – potato, ginger,from leaf – bryophyllum,begonia.
reproduction in aa) Reproductive parts of flowering plants :-flower :- The stamen and pistilare the reproductive partsof the flower. Stamen isthe male reproductive part.It produces pollen grains in the anther which
b) Pollination :- The transfer of pollengrains from the anther tothe stigma of a flower iscalled pollination. It takesplace by wind, water orinsects. If the pollen grainsare transferred from theanther to the stigma of the Cross pollination Self
c) Fertilisation :- After thepollen grain istransferred tothe stigma itproduces apollen tubewhich passesthrough the
in reproductivea) Male human beings :-system :- The male reproductivesystem consists of a pair oftestes which produces themale reproductive cellscalled sperms and thehormone testosteron. It iscontained in sac like
reproductive The female reproductive system :-system consists of a pair ofovaries which produces thefemale reproductive cellscalled ova or eggs and thehormone oestrogen. Abovethe ovaries are tubes calledoviducts or fallopian tubes.(egg) Human ovumThe two oviducts unite into a
in human During sexual intercourse beings :-the sperms from the maleenters into the vagina of thefemale. The sperms reachesthe oviduct. One sperm fuseswith an egg and forms azygote. The zygote then getsimplanted in the uterus. Thezygote then starts dividing to
d) Menstruation :- The ovary produces oneegg every month and theuterus prepares to receivethe fertilised egg. Its wallbecomes thick and spongywith blood vessels fornourishing the embryo. Iffertilisation does not take
7) Reproductive health :-a) Sexually transmitteddiseases :- are diseasestransmitted through sexualcontact. They may bebacterialinfections like gonorrhoeaand syphillis etc. or viralinfections like warts andHIV-AIDS.