List of top Biology Questions

In the operon system, the repressor protein can bind only with the
Which of the following birth control measures can be considered as the safest ?
In the homeostatic control of blood sugar level, which organs function respectively as modulator and effector ?
Passive absorption of water by root system is the result of
Two pea plants were subjected cross pollination. Of the 183 plants produced in the next generation, 94 plants were found to be tall and 89 plants were found to be dwarf. The genotypes of the two parental plants are likely to be
The chemical nature of gibberellin is that they are
In the synthesis of which of the following, the DNA molecule is not directly involved ?
The following diagrams show the types of secondary thickenings in the xylem vessels. Identify the types labelled from A to F. Choose the correct option from those given.
What is common about Trypanosoma, Noctiluca, Monocystis and Giardia?
The following is a diagram of the just spawned frog's egg, with the parts labelled from A to E. Identify the parts and choose the correct option from those given below
The formula for exponential population growth is -
Which one of the following has an open circulatory system?
The chief function of sieve tube element is:
Jurassic period of mesozoic era is characterised by-
Which one of the following is not a living fossil-
Which one of the following amino acid was not found to be synthesized in Miller's experiment?
In which one of the following sets of animals do all the four give birth to young ones?
The world biodiversity day is celebrated annually on
Which of the following plant part respires even in the absence of oxygen
Which hormone causes dilation of blood vessels, increased oxygen consumption and glycogenolysis?
Withdrawal of which of the following hormones is the immediate cause of menstruation?
Which one of the following is not a second messenger in hormone action?
Which one of the following not act as a neurotransmitter?
A major breakthrough in the studies of cells came with the development of electron microscope. This is because:
People living at sea level have around 5 million RBC per cubic millimeter of their blood whereas those living at an altitude of 5400 metres have around 8 million. This is because at high altitude: