Consider statements about ecology: 1. Nitrogen fixation is performed by cyanobacteria. 2. Denitrification releases nitrogen gas into the atmosphere. 3. Ammonification converts ammonia to nitrate. Which are correct? MCQ with Answer and Explanation

Explanation:
Gene therapy involves correcting a genetic defect by introducing a functional gene into a patient's cells. The first clinical gene therapy was given in 1990 to a 4-year-old girl with Adenosine Deaminase (ADA) deficiency, a severe combined immunodeficiency (SCID) caused by a mutation in the ADA gene. The functional ADA gene was introduced into her lymphocytes using a retroviral vector.

Explanation:
Dairy farming is the business of breeding, raising, and managing dairy animals (like cows and buffaloes) for the production of milk and milk products. Poultry farming involves the commercial raising of domesticated birds (like chickens, ducks, and turkeys) for the production of meat and eggs. Apiculture is the scientific rearing of honeybees (Apis species) for the production of honey, beeswax, and other hive products; silkworm rearing is sericulture. Thus, statements 1 and 2 are correct.

Explanation:
The domesticated silkworm, Bombyx mori, is a monophagous insect that feeds exclusively on the leaves of the mulberry plant (Morus alba). Honeybees perform a 'waggle dance' on the honeycomb to communicate the direction and distance of food sources to other worker bees. Fish farming is called pisciculture or aquaculture; sericulture specifically refers to the rearing of silkworms for silk production. Thus, statements 1 and 2 are correct.