A free-living nitrogen-fixing cyanobacterium which can also form symbiotic association with the water fern Azolla is
tolypothrix
chlorella
nostoc
anabaena
What is true about Bt toxin?
The inactive protoxin gets converted into active form in the insect gut
Bt protein exists as active toxin in the bacillus
The activated toxin enters the ovaries of the pest to sterilize it and thus prevent its multiplication.
The concerned bacillus has antitoxins.
Farmers have reported over 50% higher yields of rice by using which of the following biofertilizer?
Mycorrhiza
Azolla pinnata
Cyanobacteria
Legume-Rhizobium symbiosis
Biological control component is central to advanced agricultural production. Which of the following is used as a third generation pesticide?
Pathogens
Pheromones
Insect repellents
Insect hormone analogues
Gobar gas contains mainly
CH4 + CO2
CH4 + O2
CO2 + H2
CO2 + SO2
Genetic drift operates only in
Island populations
Smaller populations
Larger populations
Mendelian populations
In India, human population is heavily weighed towards the younger age group as a result of
Short life span of many individuals and low birth rate
Long life span of many individuals and low birth rate
Short life span of many individuals and high birth rate
Long life span of many individuals and high birth rate
Amniocentesis is a process to
Determine any disease in heart
Determine any heredity disease in the embryo
Know about the disease of brain
All the above
Consider the statements given below regarding contraception and answer as directed thereafter
(A). Medical Termination of pregnancy (MTP) during first trimester is generally safe
(B). Generally chances of conception are nill until mother breast-feeds the infant upto two year
(C). Intrauterine devices like copper-T are effective contraceptives
(D). Contraception pills may be taken upto one week after coitus to prevent conception
Which two of the above statements are correct?
B,C
C,D
A, C
A,B
Geometric representation of age structure is a characteristic of
Biotic community
Population
Landscape
Ecosystem