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 strand and capsomeres?
(1) Polio virus
(2) Tobacco mosaic virus
(3) Measles virus
(1) DNA enclosed in a protein coat
(2) prokaryotic nucleus
(3) single chromosome
(4) Both DNA and RNA
Cellulose is the major component of cell walls of
The imperfect fungi which are decomposers of litter and help in mineral cycling belong to
Select wrong statement.
(1) The viroids were discovered by D.J. lvanowsky.
(2) W.M. Stanley showed that viruses could be crystallized.
(3) The term 'contagium vivum fluidum' was coined by M.W. Beijerinek.
(4) Mosaic disease in tobacco and AIDS in human being are caused by viruses.
Choose the wrong statement.
1. Penicillium is multicellular and produces antibiotics.
2. Neurospora is used in the study of biochemical genetics.
3. Morels and truffles are poisonous mushrooms.
4. Yeast is unicellular and useful in fermentation.
The structures that help some bacteria to attach to rocks and/or host tissues are