Which of the following sets of diseases is exclusively caused by bacteria?
Cholera, typhoid, tetanus and citrus canker are bacterial diseases, whereas mumps, smallpox, herpes, influenza and AIDS are viral diseases.
Question 152 of 300
📘 CLASS XI
T.O. Diener discovered a new infectious agent that was found to be free RNA. Which disease is caused by this agent?
Viroids, discovered by T.O. Diener in 1971, consist only of free RNA and cause potato spindle tuber disease.
Question 153 of 300
📘 CLASS XI
The capsomeres, which are the small subunits that make up the protein coat of a virus, are arranged in which geometric forms?
Capsomeres are arranged in helical or polyhedral forms to constitute the viral capsid.
Question 154 of 300
📘 CLASS XI
Which statement regarding human viral diseases is correct?
Mumps, smallpox, herpes, influenza and AIDS are viral diseases.
Question 155 of 300
📘 CLASS XI
Regarding Mycoplasma, which statement is INCORRECT?
Many Mycoplasma are pathogenic in plants and animals despite lacking a cell wall.
Question 156 of 300
📘 CLASS XI
In the five-kingdom classification, Chlamydomonas and Chlorella have been grouped with Paramoecium and Amoeba in Kingdom Protista. What was their earlier placement?
Earlier systems placed Chlamydomonas and Chlorella among plants, whereas Amoeba and Paramoecium were placed among animals.
Question 157 of 300
📘 CLASS XI
Diatoms are considered the chief producers in oceans primarily because they:
Diatoms are abundant photosynthetic plankton and constitute the major primary producers in oceans.
Question 158 of 300
📘 CLASS XI
Which feature correctly describes the flagella of Euglenoids?
Euglenoids possess two flagella, one short and one long.
Question 159 of 300
📘 CLASS XI
Which statement best describes the spores of slime moulds?
Slime mould spores possess true walls, survive adverse conditions and are dispersed by air.
Question 160 of 300
📘 CLASS XI
Why is food commonly kept in a refrigerator?
Low temperature slows microbial growth, preventing bacterial and fungal spoilage.
