List of top Biology Questions asked in AIIMS

$E$. coli about to replicate was placed in a medium containing radioactive thynidine for five minutes. Then it was made to replicate in a normal medium. Which of the following observation will be correct?
"Ordines Anomali" of Bentham and Hooker includes
What is common between chloroplasts, chromoplasts and leucoplasts ?
Avena curvature test is a bioassay for examining the activity of
In angiosperms the conduction of water is more efficient because their xylem has vessels. Conduction of water by vessel elements is an active process with energy supplied by xylem parenchyma rich in mitochondria.
Which one of the following pairs of the kind of cells and their secretion is correctly matched ?
All mammals without any exception are characterised by
Genes present in the cytoplasm of eukaryotic cells are found in
A person showing unpredictable moods, outbursts of emotions, quarrelsome behaviour and conflicts with others is suffering from-
In the sieve elements, which one of the following is the most likely function of P-proteins ?
In prokaryotes, chromatophores are
Grafting is successful in dicots but not in monocots because the dicots have
A cricket player is fast chasing a ball in the field. Which one of the following groups of bones are directly contributing in this movement ?
Senescence is the time when age associated defects are manifested. Certain genes may be undergoing sequential switching on and off during one?? life.
Somaclonal variation appears in
When synapsis is complete all along the chromosome, the cell is said to have entered a stage called
Primary source of allelic variation is
Double fertilisation involves
Based on cellular mechanisms there are two major types of regeneration found in the animals. Which one of the following is the correct example of the type mentioned?
In humans, the gamete contributed by the male determines whether the child produced will be male or female. Sex in humans is a polygenic trait depending upon a cumulative effect of some genes on $X$-chromosome and some on $Y$-chromosome.
Three of the following statements regarding cell organelles are correct while one is wrong. Which one is wrong?
The family containing mustard and its main characters are
Given below is a pedigree chart showing the inheritance of a certain sex-linked trait in humans. The trait traced in the above pedigree chart is
Which one of the following four secretions is correctly matched with its source, target and nature of action?
A young drug addict used to show symptoms of depressed brain activity, feeling of calmness, relaxation and drowsiness. Possibly he was taking