Biology All India Set 2 2014-2015 Commerce (English Medium) Class 12 Question Paper Solution

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

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

State the cause of adenosine deaminase enzyme deficiency.

What is a cistron?

How many chromosomes do drones of honey bees possess?

What is mutualism?

Mention any two examples where the organisms involved are commercially exploited in agriculture.

List any four techniques where the principle of ex-situ conservation of biodiversity has been employed.

Why are the plants raised through micropropagation are termed as somaclones?

Mention two advantages of micropropagation technique.

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

(a) Select the analogous structures from the combination given below:

(i) Forelimbs of whales and bats

(ii) Eyes of octopus and mammals

(iii) Tuber of sweet potato and potato

(iv) Tuber of Bougainvillea and tendrils of Cucurbita

(b) State the kind of evolution they represent

A moss plant is unable to complete its life cycle in a dry environment. State two reasons.

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.

Explain the significance of satellite DNA in DNA fingerprinting technique.

What does the following equation represent? Explain.

p² + 2pq + q² = 1

Two independent monohybrid crosses were carried out involving a tall pea plant with a dwarf pea plant. In the first cross, the offspring population has equal number of tall and dwarf plants, whereas in the second cross it was different. Work out the crosses and explain giving reasons for the difference in the offspring population.

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

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

What are methanogens?

How do methanogens help to generate biogas?

Describe any three potential applications of genetically modified plants.

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

Explain co-evolution with reference to parasites and their hosts.

Mention any four special adaptive evolved in parasites for their parasite mode of life.

Rearrange the following in the correct sequence to accomplish an important biological 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

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

Enumerate any six essentials of good, effective Dairy Farm Management Practices.

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.

List the different attributes that a population has and not an individual organism.

“It is often said that the pyramid of energy is always upright. On the other hand, the pyramid of biomass can be both upright and inverted.” Explain with the help if examples and sketches.

(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

Describe the roles of pituitary and ovarian hormones during the menstrual cycle in a human female.

Why are color-blindness and thalassaemia categorised as Mendelian disorders? Write the symptoms of these diseases seen in people suffering from them.

About 8% of the human male population suffers from colour blindness, whereas only about 0.4% of the human female population suffers from this disease. Write an explanation to show how it is possible.

Explain the process of transcription in prokaryotes.

How is Prokaryotic Transcription process different in eukaryotes?