How do homologous organs represent divergent evolution ? Explain with the help of a suitable example.
The organs with same structural design and origin but different functions are called. homologous organs
For example in plants the thorn and tendrils of Bougainuillea and Cucurbita represent homology. Both the thorn and the tendril have a common ancestor but have evolved to perform different function in different organism. Like the thorn has a protective function whereas the tendril provides support to the plant. Thus, it represents divergent evolution.
(a) What do 'Y' and 'B' stand for in 'YAC' and 'BAC' used in Human Genome Project (HGP). Mention their role in the project.
(b) Write the percentage of the total human genome that codes for proteins and the percentage of discovered genes whose functions are known as observed during HGP.
(c) Expand 'SNPs' identified by scientists in HGP.
Name two hormones that are constituents of contraceptive pills. Why do they have high and effective contraceptive value ? Name a commonly prescribed non-steroidal oral pill.
Mention two advantages of micro propagation.
Give two examples where it is commercially adopted.
Write the two limitations of traditional breeding technique that led to promotion of micro-propagation.
Explain enzyme-replacement therapy to treat adenosine deaminase deficiency. Mention two disadvantages of this procedure.
It is generally observed that the children who had suffered from chicken - pox in their childhood may not contract the same disease in their adulthood. Explain giving reasons the basis of such an immunity in an individual. Name this kind of immunity.
