Viruses did not find a place in Whittaker's biological classification system because they are not considered truly living. What is the primary biological reason for this?
Viruses are omitted from Whittaker's classification because they are non-cellular organisms and exhibit an inert crystalline form outside the host.
Question 72 of 300
📘 CLASS XI
Which scientist discovered that the microbes causing tobacco mosaic disease were smaller than bacteria because they passed through bacteria-proof filters?
In 1892, Dmitri Ivanowsky demonstrated that the infectious agent causing tobacco mosaic disease could pass through bacteria-proof filters.
Question 73 of 300
📘 CLASS XI
What type of viral genetic material is typically found in viruses that infect animals?
Animal viruses may possess either single-stranded RNA, double-stranded RNA or double-stranded DNA.
Question 74 of 300
📘 CLASS XI
In plants, which of the following is a direct observable symptom indicating a viral infection?
Common symptoms of viral diseases in plants include mosaic formation, leaf rolling, curling, yellowing, vein clearing, dwarfing and stunted growth.
Question 75 of 300
📘 CLASS XI
The symbiotic association in lichens consists of a mutually beneficial relationship between an algal component known as the ______ and a fungal component known as the ______.
The algal partner is called the phycobiont, while the fungal partner is called the mycobiont.
Question 76 of 300
📘 CLASS XI
Which kingdom is characterised by organisms that follow a definite growth pattern and grow into adults with a definite shape and size?
Members of Kingdom Animalia exhibit a definite growth pattern and develop into adults with a definite shape and size.
Question 77 of 300
📘 CLASS XI
The life cycle of plants involves two distinct phases, the diploid sporophyte and the haploid gametophyte, that alternate with each other. This phenomenon is known as:
Plants exhibit alternation of generations involving alternating diploid sporophytic and haploid gametophytic phases.
Question 78 of 300
📘 CLASS XI
In members of Phycomycetes, asexual reproduction takes place by motile spores called ________ or by non-motile spores called ________.
Phycomycetes reproduce asexually by motile zoospores or non-motile aplanospores produced inside sporangia.
Question 79 of 300
📘 CLASS XI
Which of the following is an asexual spore produced by fungi?
Sporangiospores, conidia and zoospores are asexual spores, whereas oospores, ascospores and basidiospores are sexual spores.
Question 80 of 300
📘 CLASS XI
In fungi, a zygospore is formed by the fusion of two gametes. If these gametes are similar in morphology, they are specifically termed:
Fusion of morphologically similar gametes is called isogamy, whereas dissimilar gametes show anisogamy or oogamy.
