List of practice Questions

Lactobacillus} that sets milk into curd is categorised as:
You know that there are twenty different types of naturally occurring amino acids and four different types of bases in the DNA. A combination of 3 such bases code for a specific amino acid. If instead there are 96 different amino acids and 12 different bases in the DNA, then the minimum number of combination of bases required to form a codon is:
Which one of the following hormones is secreted by the human placenta that helps in the maintenance of pregnancy?
The periodic abstinence by a couple for family planning should be from:
Select the incorrect} match from the following:
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.
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.
Crystals of Bt toxin produced by some bacteria do not kill the bacteria producing them because:
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:
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.
In plants, which one of the following helps in the absorption of phosphorus from soil?
The most primitive ancestor of humans is:
The sequence that controls the copy number of linked DNA in the vector is termed:
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?
Which one of the following codons has dual function?
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:
Estrogen is secreted by:
Amniocentesis is a technique that is used to:
Long ribbon-like pollen grains are seen in some:

If  \(\begin{vmatrix} 2x & 3 \\ x & -8 \\ \end{vmatrix} = 0\), then the value of \(x\) is:

A window is in the form of a rectangle surmounted by an equilateral triangle on its length. Let the rectangular part have length and breadth x and y metres respectively.