Give an example of an autosomal recessive trait in humans. Explain its pattern of inheritance with the help of a cross.
Sickle Cell Anaemia is an autosomal recessive trait in humans. The genes responsible for this disease are located in autosomes. The disease being recessive the trait should be present in homozygous condition, for it to express.
People who carry a single copy of the gene are clinically normal but are carriers of the disease and can pass on the defective gene to their subsequent generation.
Identify'A' , 'B', 'C' and 'D' in the given table
| Crop | Variety | Resistance to disease |
| A | Himgiri | Leaf rust |
| Cauliflower | Pusa Shubhra | B |
| Brassica | Pusa Swarnim | C |
| Cowpea | D | Bacterial blight |
Why is breast-feeding recommended during the initial period od an infant's growth? Give reasons.
Suggest and describe a technique to obtain multiple copies of a gene of interest in vitro.
During a school trip to 'Rohtang pass' one of your classmate suddenly developed 'Altitude sickness'. But, she recovered after sometime.
(a) Mention one symptom to diagnose the sickness.
(b) What causes the sickness?
(c) How could she recover by herself after sometime?
How has RNAi technique helped to prevent the infestation of roots in tobacco plants by a nematode Meloidegyne incognita?
In in a food-chain, a trophic level represents a functional level, not a species. Explain.
