Q. A geneticist interested in studying variations and patterns of inheritance in living beings prefers to choose organisms for experiments with shorter life cycle. Provide a reason.

Q. During a monohybrid cross involving a tall pea plant with a dwarf pea plant, the offspring populations were tall and dwarf in equal ratio. Work out a cross to show how it is possible.

Q. Rearrange the following in the current sequences to accomplish an important biotechnological reaction.
(a) In vitro synthesis of copies of DNA of interest
(b) Chemically synthesized oligonucleotides
(c) Enzyme DNA-polymerase
(d) Complementary region of DNA
(e) Genomic DNA template
(f) Nucleotides provided
(g) Primers
(h) Thermostable DNA-polymerase (from Thermus aquaticus)
(i) Denaturation of ds-DNA

Q. In mosses, sexual reproduction cannot be completed without water. A moss plant is unable to complete its life-cycle in a dry environment. State two reasons.

Q. Explain the process of secondary treatment given to the primary effluent up to the point it shows a significant change in the level of biological oxygen demand (BOD) in it.

Q.

State the medicinal value and the bioactive molecules produced by Streptococcus and Trichoderma.

Q. (a) Plan an experiment and prepare a flow chart of the steps that you would follow to ensure that the seeds are formed only from the desired sets of pollen grains. Name the type of experiment that you carried out.
(b) Write the importance of such experiments.

Q. What is cistron?

Q. In two independent crosses between tall pea plants and dwarf pea plants, the following observations were noted down:

Q. Explain the different steps involved during primary treatment phase of sewage.

Q. How did an American Company, Eli Lilly use the knowledge of r-DNA technology to produce an insulin?

Q. Five Mark Questions.
(a) List the different attributes that a population has and not an individual organism.
(b) What is population density? Explain any three different ways the population density can be measured, with the help of an example each.

Q. Your school has been selected by the department of education to organize and host an interschool seminar on "Reproductive Health - Problems and Practices". However, many parents are reluctant to permit their wards to attend it. Their argument is that the topic is "too embarrassing". Put forth four arguments with appropriate reasons and explanation to justify the topic to be very essential and timely.

Q. With the help of a flow-chart exhibit the events of eutrophication.

Q. A heavily bleeding and bruised road accident victim was brought to a nursing home. The doctor immediately gave him an injection to protect him against a deadly disease.
(a) Write what did the doctor inject into the patient's body.
(b) How do you think this injection would protect the patient against the disease?
(c) Name the disease against which this injection was given and the kind of immunity it provides.

Q. State the cause of adenosine deaminase enzyme deficiency.

Q. Why do children cured by enzyme-replacement therapy for adenosine deaminase deficiency need periodic treatment?

Q. Retroviruses have no DNA. However, the DNA of the infected host cell does possess viral DNA. How is it possible?

Q. List two advantages of the use of unleaded petrol in automobiles as fuel.

Q. Enumerate any six essentials of good, effective dairy farm management practices.

Q. Two Mark Questions.
What is mutualism? Mention any two examples where the organisms involved are commercially exploited in agriculture.

Q. How do snails, seeds, bears, zooplanktons, fungi and bacteria adapt to conditions unfavourable for their survival?

Q. State what is apomixis. Comment on its significance. How can it be commercially used?

Q. With the help of a flow chart, show the phenomenon of biomagnification of DDT in an aquatic food chain.

Q. (a) Why are thalassemia and haemophilia categorized as Mendelian disorders? Write the symptoms of these diseases. Explain their pattern of inheritance in humans.
(b) Write the genotypes of the normal parents producing a haemophilic son.

Q. Why do moss plants produce very large number of male gametes? Give one reason. What are these gametes called?

Q. (a) Why are colour blindness and thalassemia categorised as Mendelian disorders? Write the symptoms of these diseases seen in people suffering from them.
(b) About 8% of human male population suffers from colour blindness whereas only about 0.4% of human female population suffers from this disease. Write an explanation to show how it is possible.

Q. Explain the significance of satellite DNA in DNA fingerprinting technique.

Q. Explain co-evolution with reference to parasites and their hosts. Mention any four special adaptive features evolved in parasites for their parasitic mode of life.

Q. What does the following equation represent? Explain $p^2+2pq+q^2=1$