Q. Name one air borne and a water borne disease in humans. List one specific symptom of each one of them.

Q. Name the two techniques employed to meet the increasing demand of fish in the world.

Q. Name any two fresh water fishes.

Q. Write the palindromic nucleotide sequence EcoRI recognises.

Q. Describe the contributions of Alexander Fleming, Ernest Chain and Howard Florey in the field of microbiology.

Q. All cloning vectors do have a 'selectable marker'. Describe its role in recombinant DNA-technology.

Q. Mention how have plants developed mechanical and chemical defence against herbivores to protect themselves with the help of one example of each.

Q. How is humus formed ? Mention any three characteristics of humus.

Q. Large-hole in 'Swiss-Cheese' are due to

1. Propionibacterium shermanii
2. Saccharomyces cerevisae
3. Penicillium chrysogenum
4. Acetobacter aceti

Q. Name the enzyme that helps in forming recombinant DNA.

Q. State what are Mendelian disorders. Both thalassemia and colour blindness are categorised as Mendelian disorders. Justify.

Q. State two advantages of an apomictic seed to a farmer.

Q. Differentiate between "Pioneer-species"; 'Climax-community" and "Seres".

Q. Increased concentration of DDT in fish-eating birds is due to

1. Eutrophication
2. Bio-magification
3. Cultural Eutrophication
4. Accelerated Eutrophication

Q. Species-Area relationship is represented on a log scale as

1. Hyperbola
2. Rectangular hyperbola
3. Linear
4. Inverted

Q. When does the population in a metro city tend to increase ?

Q. When does the population in metro city tend to decline?

Q. Explain any three ways other than zoological parks, botanical gardens and wildlife safaries, by which threatened species of plants and animals are being conserved 'ex situ'.

Q. If '$N$' is the population density at the time 't', write the population density at the time '$t+1$'.

Q. Explain 'Integrated organic' farming as successfully practiced by Ramesh C. Dagar, a farmer in Sonepat (Haryana).

Q. Study the diagram showing the entry of HIV into the human body and the processes that are followed.
Name the human cell 'A' HIV enters into

Q. Study the diagram showing the entry of HIV into the human body and the processes that are followed.
Mention the genetic material 'B' HIV releases into the cell.

Q. Explain the mode of action of $C{u}^{++}$ releasing IUDs. How are hormone releasing IUDs different from them?

Q. Study the diagram showing the entry of HIV into the human body and the processes that are followed.
Identify enzyme 'C'.

Q. Name the insect that attacks cotton crops and causes lot of damage to the crop. How has Bt cotton plants overcome this problem and saved the crop? Explain

Q. Why is 'Saheli' a preferred contraceptive by women? State any two reasons.

Q. Write the role of gene Cry $IAb$.

Q. Following a road accident four injured persons were brought to a nearby clinic. The doctor immediately injected them with tetanus antitoxin.
What is tetanus antitoxin ?

Q. Following a road accident, four injured persons were brought to a nearby clinic. The doctor immediately injected them with tetanus antitoxin.

Q. Explain the different steps carried out in Polymerase Chain Reaction, and the specific roles of the enzymes used.