(i) Relationship between (1) and (2) is of predator-prey relationship.
(ii) Relationship between (3) and (4) is producer and (3) is primary consumer.

Scrubber. A scrubber can remove gases like sulphur dioxide. In a scrubber, the exhaust is passed through a spray of water or lime. Water dissolves gases and lime reacts with sulphur dioxide to form a precipitate of calcium sulphate or sulphite.

(i) Acetic acid - Acetobacter aceti
(ii) Butyric acid - Clostridium butylicum
(iii) Lacteric acid - Lactobacillus delbruekii

(a) Farmers prefer biofertilisers to chemical fertilisers for the following differences between them:

(b) Anabaena acts as biofertiliser because
(i) It fixes atmospheric nitrogen and enriches soil fertility.
(ii) By its photosynthesis, it adds organic matter to soil.
Mycorrhizae are the symbiotic associations between certain fungi and roots of higher plants.
Mycorrhizae act as biofertiliser because - The fungus absorbs phosphorus from the soil and passes it to the plant.
Plants with mycorrhiza show resistance to root-borne pathogens.
They show increased tolerance to salinity and drought.
There is an overall increase in plant growth and development.

Scrubber
1. It is used to remove gases like sulphur dioxide from industrial exhaust.
2. The exhaust is passed through a spray of water or lime.
3. Water dissolves the gases and lime reacts with sulphur dioxide to form a precipitate of calcium sulphate or sulphite.

(i) The conventional taxonomic methods are not suitable/sufficient for identifying these microbes.
(ii) Many of these cannot be cultures under laboratory conditions.
(iii) Biochemical and molecular biology techniques wopuld put their diversity into millions.

All organisms/animals which depend directly or indirectly on plants for their food are called consumers.
Consumers are of the following types:
(i) Primary consumers
They are the organisms/animals which depend directly on producers for their food;they are also called as herbivores,e.g. deer, rabbit, zooplanktons.
(ii)Secondary consumers
Secondary consumers are those animals which depend on the primary consumers for their food; they are primary carnivores, e.g frogs,hyena.
(iii)Tertiary consumers
Tertiary consumers are those animals which depend on the secondary consumers for their food;they are the secondary carnivores, e.g. lion, eagle, kite, etc.

1. The pyramid is inverted.
2. Since the biomass of fishes far exceeds that of the phytoplanktons, the pyramid is inverted.

Poultry is the class of domesticated fowl (birds) used for food -either meat or eggs.The birds include chicken,ducks,turkey and geese.

(a) Multiple ovulation Embryo Transfer , (MOET) technology
(b) Steps in MOET technology:
A cow is administered hormones with FSH-like activity to induce follicular maturation and superovulation, i.e. instead of one egg, 6-8 eggs are produced per cycle.
The animal is either mated with an elite bull or artificially inseminated.
The fertilised eggs are recovered at the 8-32 celled stages, nonsurgically.
They are then transferred to surrogate mothers.
The genetic mother is available for and her round of superovulation.

Deletion of the gene for ADA causes ADAdeficiency, i.e. deficiency of adenosine deaminase, the enzyme which is crucial for the normal functioning of our immune system.
 ADA deficiency can be cured by:
(i) Bone marrow transplantation.
(ii) Enzyme replacement therapy in which functional ADA is given by injection.
(iii) Gene therapy, in which functional ADA cDNA is introduced into lymphocytes or into cells at early embryonic stage.

Reduces inbreeding depression.

Wastes from agricultural field /& Industrial effluents, because they are non-Biodegradable and toxic.

Bt cotton was commercially planted for the first time in 1996/97 in Australia and U.S.A

Conventional agricultural practices, with the use of locally available good quality seeds, compost, manure and biofertilisers, are more ecofriendly whereas modern agricultural practices are causing ecological damage due to enormous exploitation of natural resources and unmanageable amount of by-products and wastes that are being constantaly added into the atmosphere.

Functions of LAB;
LAB are used to convert milk into curd are employed in dairy industries.
LAB in human intestine synthesize vitamin B₁₂
LAB in human stomach check the growth of harmful microbes 

1. Only 51% of solar energy reaches the earth surface.
2. It is because it is absorbed by the gases and molecules in the atmosphere.

Sex ratio refers to the ratio between the number of males and the number of females of a given population, at a given time.  It is characteristic of a population.