16 ^|

A Handbook of Biology

RËPRØDÜÇTÏØÑ ÏÑ BÅÇTËRÏÅ

Bacteria reproduce mainly by fission.

Under unfavourable conditions, they produce spores.

They also reproduce by a sort of sexual reproduction (DNA

transfer) from one bacterium to other.

MÝÇØPLÅSMÅS (PPLØ)



These are organisms without a cell wall. They are the smallest living cells.

They can survive without oxygen. Many are pathogenic in animals and

plants. (NEET 2017)

KÏÑGDØM PRØTÏSTÅ



It includes single celled eukaryotes



The cell contains a well-defined nucleus and other membrane-bound

organelles. Some have flagella or cilia.



Protists are primarily aquatic.



It is a link with plants, animals and fungi.



They reproduce asexually and sexually (cell fusion and zygote

formation).



Protista includes Chrysophytes, Dinoflagellates, Euglenoids, Slime

moulds and Protozoans. (NEET-2016)



Protists may be autotrophs (photosynthetic), symbionts or heterotrophs.



It is a heterogenous group because the boundaries of this kingdom are

not well-defined.