Answer:
The correct option is A, since if the DNA enters in a circular form it is called a plasmid, and the plasmids upon entering the bacteria self-replicate outside the genetic structure, which gives the bacteria better survival qualities.
Explanation:
Plasmids are generally circular extrachromosomal DNA molecules that replicate and transmit independently of chromosomal DNA, and are normally present in bacteria, archaea, and sometimes in eukaryotic organisms such as yeast. Its size varies from 3 to 10 kb. The number of plasmids can vary, depending on their type, from a single copy to a few hundred per cell. Plasmid vectors allow cloning of exogenous DNA ligands of up to 4 kb since a larger size than this makes cloning in these vectors difficult. The term plasmid was first introduced by the American molecular biologist Joshua Lederberg in 1952. Plasmids can only coexist as one or more copies in each bacterium, due to cell division they can be lost in one of the secreted bacteria.
<u>ANSWER:</u>
When a supergiant runs out of fuel, the object formed is either a black hole or a neutron star.
<u>EXPLANATION:</u>
- Supergiant are very large stars in the galaxy that end their lives very quickly.
- When a supergiant star loses its fuel, it blows itself by a supernove explosion.
- When supernove explosion happens, the supernova outshines other stars in the galaxy and then slowly faded away leaving a dense object called black hole or neutron star.
- This black hole or neutron star is surrounded by a mass of very hot gas and the elements of the supergiant star get scattered into the space.
Hydrogen would be the answer to this.
