Answer:
The correct answer will be-
1. Nucleosomes
2. Chromatin
3. Sister chroamtid
4. Centromere
Explanation:
The DNA is a very long molecule which if has to be passed on to the daughter cell as it is will cause problems. So, to reduce problems a cell form tightly packed structure of DNA so that they can be passed easily to the daughter cell.
The packaging of DNA begins with the wrapping of the DNA around histone proteins which forms the 11 nm basic structural units called nucleosomes. The nucleosomes start condensing each other and form 30 nm structure chromatin fibres.
The chromatin fibres undergo replication during S phase which produces an exact copy of the chromatin called sister chromatids bound to each other at a central point called centromere which helps the separation of the chromatids during M phase.
You answer would be D.) Genetic Engineering.
Hope this Helps =)
Foreign invaders have proteins called antigen, which antibodies lock onto to neutralize. The foreign proteins are different from proteins in our own body, so the immune system can recognize them and finally eliminate them.
Answer is thorax...
Hope it helps you...