Multiple Choice QuestionsAdvantage of cleistogamy is
higher genetic variability
more vigorous offspring
no dependence on pollinators
vivipary
C.
no dependence on pollinators
In cleistogamous flowers, anthers and stigma lie close to each other. When anthers dehisce in the flower buds, pollen grains come in contact with the stigma to effect pollination. Thus, these flowers produce assured seed set even in the absence of pollinators.
The higher genetic variability and more vigorous offsprings are produced to variations obtained by sexual reproduction. Vivipary relates to the birth of young babies from mammals.
Monoecious plant of Chara shows occurrence of
antheridiophore and archegoniophore on the same plant
stamen and carpel on the same plant
upper antheridium and lower oogonium on the same plant
upper oogonium and lower antheridium on the same plant
Perisperm differs from endosperm in
being a haploid tissue
having no reserve food
being a diploid tissue
its formation by fusion of secondary nucleus with several sperms
Which of the, following statements is not true of two genes that show 50% recombination frequency?
the genes may be on different chromosomes
the genes are tightly linked
the genes show independent assortment
if the genes are present on the same chromosome, they undergo more than one cross overs in every meiosis
Variation in gene frequencies within populations can occur by chance rather than by natural selection. This is referred to as
genetic flow
genetic drift
random mating
genetic load
If two persons with 'AB' blood group marry and have sufficiently large number of children, these children could be classified as 'A' blood group : 'AB' blood group : 'B' blood group in 1 : 2 : 1 ratio. Modern technique of protein electrophoresis reveals presence of both 'A' and 'B' type proteins in 'AB' blood group individuals. This is an example of
codominance
incomplete dominance
partial dominance
complete dominance
The process by which organisms with different evolutionary history evolve similar phenotypic adaptations in response to a common environmental challenge, is called
natural selection
convergent evolution
non-random evolution
adaptive radiation
The tendency of population to remain in genetic equilibrium may be disturbed by
random mating
lack of migration
lack of mutations
lack of random mating
Which of the following Bt crops is being grown in India by the farmers?
Maize
Cotton
Brinjal
Soyabean
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