Thermococcus, Methanococcus and Methanobacterium exemplify
(1) archaebacteria that contain protein homologous to eukarytic core histones
(2) archaebacteria that lack any histones resembling those found in eukaryotes but whose DNA is negatively supercoiled
(3) bacteria whose DNA is relaxed or positively supercoiled but which have a cytoskeleton as well as mitochondria
(4) bacteria that contain a cytoskeleton and ribosomes
Which of the following is a flowering plant with nodules containing filamentous nitrogen-fixing microorganism?
(1) Casuarina equisetifolia
(2) Crotolaria juncea
(3) Cycas revoluta
(4) Cicer arietinum
Which of the following is a slime mould?
Ergot of rye is caused by a species of:
A genetically engineered micro-organism used successfully in bioremediation of oil spills is a species of:
Two plants can be conclusively said to belong to the same species if they:
(1) can reproduce freely with each other and form viable seeds
(2) have more than 90 percent similar genes
(3) look similar and possess identical secondary metabolites
(4) have same number of chromosomes
True nucleus is absent in
Cell wall is absent in
Which of the following shows coiled RNA starand and capsomeres?
(1) Polio virus
(2) Tobacco mosaic virus
(3) Measles virus