List of top Biology Questions

How does the process of Natural Selection affect Hardy-Weinberg equilibrium? Explain with the help of graphs.
Write the composition of intine and exine layers of a pollen grain.
List two reasons that make copper releasing IUDs as effective contraceptives.
Explain how the intake of oral contraceptive pills prevent pregnancy in humans.
State the advantage of using thermostable DNA polymerase.
State the conclusions derived by David Tilman’s long-term ecosystem experiments using outdoor plots.
A bilobed dithecous anther has 200 microspore mother cells per microsporangium. How many male gametophytes can be produced by this anther?
The symptoms of malaria do not appear immediately after the entry of sporozoites into the human body when bitten by female Anopheles mosquito. Explain why it happens.
Write the scientific name of the source organism of the thermostable DNA polymerase used in PCR.
Assertion (A): Restriction endonuclease recognises palindromic sequence in DNA and cuts them. Reason (R): Palindromic sequence has two unique recognition sites PstI and PvuI recognised by restriction endonuclease.
Mention any four strategies adopted by flowering plants to prevent self-pollination.
Describe any two situations where a medical doctor would recommend injection of pre-formed antibodies (antitoxins) into the body of a patient.

Study the given pedigree chart in which neither of the parents shows the trait but the trait is present in both male and female children.

pedigree chart

Write about the trait, also explain the inheritance of such a trait in the progeny on the basis of the given pedigree chart.

Study the given pedigree chart in which neither of the parents shows the trait but the trait is present in both male and female children.

pedigree chart

Give one example of such a trait in human beings.

(A) Comment upon the mode of pollination in Vallisneria and Zostera. (B)
Assertion (A): Streptococcus pneumoniae and \textit{Haemophilus influenzae} are responsible for causing infectious disease in human beings. Reason (R): A healthy person acquires the infection by inhaling the aerosols released by an infected person.
Assertion (A): The number of white winged moths decreased after industrialisation in England. Reason (R): Effects of industrialisation were more marked in rural areas of England.
Select the correct statement from the following biotechnological procedures:
For commercial and industrial production of citric acid, which one of the following microbes is used?
Assertion (A): Corpus luteum secretes the hormone, progesterone. Reason (R): Hormone Progesterone is essential for maintenance of the endometrium.
The decrease in the T-Lymphocytes count in human blood will finally result in

Given below is a heterogeneous RNA formed during Eukaryotic transcription:

heterogeneous RNA

How many introns and exons respectively are present in the hnRNA?

Which of the following features correctly show the mechanism of sex-determination in honey-bees?
If Meselson and Stahl’s experiment is continued for 80 minutes (till III generation), then what would be the ratio of DNA containing \( N^{15}/N^{15} : N^{15}/N^{14} : N^{14}/N^{14} \) in the medium?

Study the items of Column-I and those of Column-II:

Choose the option that correctly matches the items of Column-I with those of Column-II: