List of top Biology Questions

Samples of blood and urine of a sportsperson are collected before any sports event for drug tests.
(a) Why there is a need to conduct such tests?
(b) Name the drugs the authorities usually look for.
(c) Write the generic names of two plants from which these drugs are obtained.
How does the process of Natural Selection affect Hardy-Weinberg equilibrium? Explain with the help of graphs.
Using a Punnett square workout the distribution of an autosomal phenotypic feature in the first filial generation after a cross between a homozygous female and a heterozygous male for a single locus.
(a) List two reasons that make copper releasing IUDs as effective contraceptives.
(b) Explain how the intake of oral contraceptive pills prevent pregnancy in humans.
(a) A bilobed dithecous anther has 200 microspore mother cells per microsporangium. How many male gametophytes can be produced by this anther?
(b) Write the composition of intine and exine layers of a pollen grain.

Student to attempt either option (A) or (B).
(A) Identify the type of pyramid given below and write two identifying features of such a pyramid: 

OR 
(B) 
(i) Construct an ideal pyramid of energy when 10,00,000 Joules of sunlight is available. 
(ii) Mention the energy obtained by the fourth level of this pyramid.} 
 

Observe the given sequence of nitrogenous bases on a DNA fragment and answer the following questions:

(a) Name the restriction enzyme which can recognise the DNA sequence. 
(b) Write the sequence after restriction enzyme cut the palindrome. 
(c) Why are the ends generated after digestion called as ‘Sticky Ends’?

Student to attempt either option (A) or (B).
(A) Describe any two situations where a medical doctor would recommend injection of pre-formed antibodies (antitoxins) into the body of a patient. 
OR 
(B) 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.

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.

Answer the following questions: 
(a) Write the trait, also explain the inheritance of such trait in the progeny on the basis of given pedigree chart. 
(b) Give one example of such trait in human beings.

Student to attempt either option (A) or (B):
(A) 
(i) Write two crucial changes, the seed undergoes while reaching maturity that enable them to be in a viable state until the onset of favourable conditions. 
(ii) Name the oldest viable seed excavated from Arctic Tundra as per the records. 
OR (B) 
(i) Pea flower produced seed sets. Give reason. 
(ii) In case of Polyembryony, an embryo ‘P’ develops from a synergid and the embryo ‘Q’ develops from the nucellus. State the ploidy of embryo ‘P’ and ‘Q’.

Assertion (A): Restriction endonuclease recognises palindromic sequence in the DNA and cuts them.
Reason (R): Palindromic sequence has two unique recognition sites PstI and PvuI recognised by the restriction endonuclease.
Assertion (A): Streptococcus pneumoniae and 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.
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
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?
Study the items of Column-I and those of Column-II:
Column-I Column-II
(a) RNA polymerase I (i) 18s rRNA
(b) RNA polymerase II (ii) SnRNAs
(c) RNA polymerase III (iii) hnRNA
Choose the option that correctly matches the items of Column-I with those of Column-II:

Given below is a heterogeneous RNA formed during Eukaryotic transcription:
 
How many introns and exons respectively are present in the hnRNA?

The phosphoester linkage in the nucleotides is between
Which one of the following options shows the correct evolutionary order of the plants mentioned below?
(i) Ferns (ii) Ginkgo (iii) Zosterophyllum (iv) Gnetales
Choose the correct option.

In a pedigree chart represents :

A child with blood group A has the father with blood group B and the mother with blood group AB. Choose the option that gives the correct genotypes of father, mother and the child :
The number of autosomes present in a human secondary spermatocyte

Given below is a diagram of T.S. of a monocot seed with parts I, II & III labelled :

Choose the option where parts I, II and III are identified correctly.