Reproductive Health — BIOLOGY STD 12 Science — Question

With a labeled diagram write a short note on formation of embryo sac.###Explain internal structure of embryo sac###With a neat diagram, explain the 7-celled, 8 nucleate nature of female gametophyte.

Write about the ancestry and evolution of bat, horse and human on the basis of a comparative study of their forelimbs. What are these limbs categorized as?
OR
What is divergent evolution? Explain taking an example of plants.

OR
Divergent evolution leads to homologous structures. Explain with the help of an example.

How are transgenic animals used in chemical safety testing?

Sperms have a tail whereas egg does not, why?

What is a terminator in a transcription unit? Where is it located in a structural gene? Mention its significance in transcription.

How is evaluation and testing of the new variety carried out?

What do you understand by phenotype and genotype? Explain by giving an exmple.

Name the species in the blanks a and b given below-
Ramapithecus → a → b → Homo erectus Homo sapiens.

Name any two organisms and the phenomenon involved where the female gamete undergoes development to form new organisms without fertilisation.

Draw a labelled diagram of female reproductive system.