Question

First successful animal clone wars
A. Dolly goat
B. Dolly sheep
C. Molly goat
D. Molly sheep

Answer 1

Cloning makes identical copies of plants or animals. Animals like mice, sheep, frogs, and cows have been cloned in the past. Cloning can be natural or molecular. Natural cloning is also the normal reproduction process followed by many plants in particular. Molecular cloning amplifies DNA fragments containing genes. This technique is extensively used in biological experimentation.

Complete answer:
- Here, it should be noted that two mammals namely Polly and Molly were the first to be cloned and they were also said to be transgenic animals.
- Dolly the sheep was the very first successful clone. Scientists first of all used cells from a Finn Dorset which was a white sheep. The cells had to be reprogrammed and be under growth control. There were alterations made in the growth medium to keep the cells alive.
- They injected the cell into an unfertilized egg cell (from Scottish Blackface ewe) with the removed nucleus. Then they were fused by the application of electric pulse.
- The resulting cell has to develop into an embryo. Cell culture was done for a week or so to check for the proper division and normal development. Only by ensuring it, they could implant into a surrogate mother which would be the other Scottish Blackface ewe.
- Hence Dolly was successfully cloned and born on 5 July in the year 1996. She mated to produce normal offspring without any difficulties.
- Sadly, she could not survive much and initially suffered from arthritis and then from sheep pulmonary adenomatosis which caused lung tumor. She died on 14 February in the year 2003.

Hence, the correct answer is option (B).

Note: Advantages of cloning include; helping infertile couples to bear children, it can potentially cure diseases and has a great contribution in organ replacement. With these advantages there are also some disadvantages like; cloning is not very certain so there is always a risk. Organ rejection can also be a major problem, gene diversity is greatly decreased and there are in-breeding problems also seen. To support it or oppose it, differs from person to person.