The viruses that infect bacteria,multiply within them,and cause their lysis are called .........

What was the contribution of the scientist $M. W. Beijerinck$ in $1898$ regarding the study of viruses?

Match Column-$I$ with Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$(A)$ Tobacco Mosaic Virus	$(p)$ Human
$(B)$ Potato Spindle Tuber Disease	$(q)$ Bacterial Virus
$(C)$ Alzheimer's Disease	$(r)$ Plant Virus
$(D)$ Bacteriophage	$(s)$ Tobacco
$(E)$ Polio Virus	$(t)$ Potato
	$(u)$ Animal Virus

Which of the following contains a helical $RNA$ strand and capsomeres?

Read the following statements carefully and identify correct statements $w.r.t.$ Lichens:
$a.$ The association cannot tolerate air pollution,especially due to sulphur dioxide.
$b.$ Lichens are annuals and their growth is slow.
$c.$ The fungal partner mostly belongs to Ascomycetes.
$d.$ Soredia are most efficient means of asexual reproduction.
$e.$ Orchids seldom occur without this association.
$f.$ Foliose lichens are pioneers of succession in a water body.

Which statement is wrong about lichens?