Some objects in space are created from clouds of gas and dust. A star forms when the mass of the dust cloud is large and has enough hydrogen to start creating a protostar and sustain the nuclear fusion reaction within the core of the protostar. If the dust cloud is not dense enough, then the star formation does not take place, rather a nebula is formed, example the Horse-head nebula. So the answer is (B) A star will not form.
The correct answer is option D, They both lack nuclear membrane
Both Archaea and Bacteria belongs to the prokaryotic and thus have no cell nucleus or any other membrane-bound organelles in their cells. These two are single celled and reproduce through binary fission.
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms.