A patient reports a high fever, chills and sweating. His blood shows the presence of a toxic substance.
(i) Identify the disease and the causative organism.
(ii) Explain why this disease shows recurring pattern of fever.
Taylor and colleagues performed an experiment on which of the following organisms to provide proof for semi-conservative replication of DNA in chromosomes ?
The method of contraception that is hormone-based and prevents ovulation is :
Which cells are responsible for producing antibodies in a human body ?
Which part of the ovule hardens to form seed coat of a seed ?
Consider the following statements and choose the correct option :
Statement I : Using vaccination and immunization programmes, we have been able to eradicate smallpox.
Statement II : Vaccines are available for diphtheria and polio.
Read the following passage and answer the questions that follow :
India is one of the megadiverse countries housing around 8.1 per cent of global species diversity, although its land area is only 2.4 per cent of the world's land area. Many of the species are highly threatened due to human activities like deforestation, mining and habitat fragmentation. Laws like Wildlife (Protection) Act, 1972 were enacted by the Government of India to preserve our biological wealth. Various conservation measures are being implemented to save the threatened species.
The following bar graph shows the number of species conserved under different biodiversity conservation methods.
[Bar graph: "Species Conserved under Different Biodiversity Conservation Methods"; x-axis Conservation Method, y-axis Number of Species Conserved (0 to 3000). National Parks 1100, Wildlife Sanctuaries 2500, Biosphere Reserves 1200, Zoological Parks 990, Botanical Gardens 1100.]
Study the graph and answer the questions.
(a) Which method conserves the highest number of species ? Is it ex situ or in situ conservation ?
Read the following passage and answer the question that follow :
The data below shows the concentration of nicotine smoked by a smoker taking 10 puffs/minute.
[Graph: "Smoking Cigarette", concentration of nicotine in blood (mg/cm3) against time (minutes), 1 to 15. The line rises steadily from about 0 at 1 minute to a peak of 45 at 10 minutes, falls sharply to 20 at 11 minutes, then declines slowly to about 10 at 15 minutes.]
(a) (i) With reference to the above graph, explain the concentration of nicotine in the blood at 10 minutes.
(b) How does cigarette smoking result in high blood pressure and increase in heart rate ?
(a) (ii) How will this affect the concentration of carbon monoxide and haem-bound oxygen at 10 minutes ?
(c) To which class of compounds does nicotine belong ? Name one other drug from the same class.
(i) Given below is the schematic representation of the process of electrophoresis. Identify the alphabets representing the :
(I) Anode end, and
(II) Lightest/Smallest DNA in matrix.
(ii) What is Agarose gel and why is it used in this process ?
Match Column I with Column II and select the correct option :
Sexually transmitted infections are a major threat to our society. So it is said that "Prevention is better than cure".
(i) Write the three simple principles to be followed to prevent such infections.
(ii) How can sex education programs in schools help in improving reproductive health ? (4 points)
In the given diagram, A is an embryonic stage that gets transformed into B, which in turn gets implanted in the endometrium of human female.
(i) (1) Identify A, B, C and D.
(2) State the fate of C immediately after implantation.
(3) Name the special cells found in C and their function.
(ii) What is the role of oxytocin during parturition ? Where is it released from ?
(a) Compare homologous and analogous organs by giving any one point of difference.
(b) Mention the type of evolution each represents and give one example of each from plants and animals.
Study the diagram given below :
(a) Name and explain the procedure shown in the diagram. Mention one of its advantage and one disadvantage.
(b) How is Saheli different from other oral pills in terms of its composition and advantage ?
Biodiversity exists at various levels within an ecosystem. Explain biodiversity at genetic and ecological level.
Explain the type of interaction between :
(i) Egret and Cattle
(ii) Cuckoo and Crow
Study the flow chart and answer the following questions :
(a) Identify A, B and C in the flow chart.
(b) Give one another example of bio-fertilizer B.
6. Current percentage of tropical rainforests covering the Earth's land surface is
Assertion (A) : Under a particular set of selection pressure, organisms evolve towards the most efficient reproductive strategy.
Reason (R) : Populations evolve to maximise their reproductive fitness in the habitat where they live.
If any organ fails to function satisfactorily, transplantation is the only remedy to enable the patient to live a normal life.
All of the following are true w.r.t. transplantation except -
Study the given pedigree and identify the disease represented.
A patent with Type I diabetes is unable to produce sufficient insulin.
(a) How has recombinant DNA technology helped in addressing this problem ?
(b) Mention its advantage over animal derived insulin.
