List of top Biology Questions asked in CBSE Compartment Exam Class XII

Select the incorrect} match from the following:
In which of the following plants are both male and female flowers born on the same plant and the mode of pollination can be geitonogamy or xenogamy?
The mosquito-borne disease in humans causing chronic inflammation of the lymphatic vessels is:
Assertion (A): Biotechnology produces transgenic micro-organisms that act as microfactories for proteins.
Reason (R): To produce proteins for human use like insulin, transgenic microorganisms can be developed.
Assertion (A): Gross primary productivity is always less than net primary productivity.
Reason (R): Rate of synthesis of organic matter by consumers is known as secondary productivity.
Assertion (A): Streptococcus pneumoniae} and Haemophilus influenzae} are responsible for causing infectious diseases in human beings.
Reason (R): A healthy person acquires the infection by inhaling the droplets/aerosols released by an infected person.
Assertion (A): Periodic abstinence is a method in which couples avoid coitus from day 10 to 17 of menstrual cycle.
Reason (R): Periodic abstinence has limited effectiveness because menstrual cycles are not always regular.
The population interaction where one species is harmed and the other is unaffected is:
Crystals of Bt toxin produced by some bacteria do not kill the bacteria producing them because:
In plants, which one of the following helps in the absorption of phosphorus from soil?
The sequence that controls the copy number of linked DNA in the vector is termed:
The most primitive ancestor of humans is:
In humans, non-disjunction of the 21st pair of chromosomes leads to:
The mosquito-borne disease in humans causing chronic inflammation of the lymphatic vessels is:
Which one of the following codons has dual function?
Which one of the following options gives the correct temperature condition and the mixture of the gaseous components that were used by S.L. Miller in 1953 to prove abiogenesis of life?
Estrogen is secreted by:
Amniocentesis is a technique that is used to:
Long ribbon-like pollen grains are seen in some: