We have already learnt about the Reproduction in our previous classes but at now we go throughly and deeply to understand it better then ever.
*The Life Span is the period from birth to natural death of an organisms
.* And Life Span is not related to the size of an organisms.E.g. The size of parrot of and crow is similar but the Life Span period is different (Parrot life span is approx.140years and crow's approx.15years).
*No one organisms is immortal except single celled organisms.
WHAT IS REPRODUCTION?
Reproduction is defined as the biological process in which an organisms gives rise to a young ones (offspring) similar to itself.
TYPES OF REPRODUCTION:
1)ASEXUAL REPRODUCTION:-When an offspringis produced by single parent with or without involvement of Gametes.
*This reproduction occured in single individual.
*Offsprings are the exact copies of their parents and that's why they called as the ''CLONE''.E.g. In protists and moneras the parent cell divide itself to form into young ones.
TYPES OF ASEXUAL REPRODUCTION
A)BINARY FISSION:Cell divides into 2 halves and aech part grow and become a adult.
*Binary fission have three types
1)Transverse binary fission:In Bacteria and Paramecium.
2)Longitudinal binary fission:In Euglena.
3)Simple binary fission:In Amoeba.
Binary fission in Amoeba
B)BUDDING:Due to unequal division small buds are produced, which initially are attached to parent but later they separateto form new individual E.g.Yeast.
Budding in Hydra
3)SPORULATION:Some members of kingdom Fungi and simple plants reproduce through asexual structures like Zoospores or Gemmules or Conidie.
4)FRAGMENTATION:Fragments are formed in some algae (spirogyra,fungi etc.).
Fragmentation in algae
4)VEGETATIVE PROPAGATION:In plants some parts are capable to giving a rise to new ones.Those structure are called as Vegetative Propagules and the process is known as the Vegetative Propagation.
E.g.:Runner,Rhizome,Offset,Bulb,Sucker,Tuber etc.
SEXUAL REPODUCTION:
............Continued in part 2
No comments:
Post a Comment