Answer: Option D.
Crystalline and rigid.
Explanation:
When liquid freezes to ice, it becomes solid and this is crystalline and rigid because a solids for crystals which means solid atoms, molecules or ions are orderly arranged in structures which form of crystal lattice in all sides. The structure of solid becomes rigid , it does not take the container shape like liquid and it does not expand also like liquid. it volumes reduces.
➜ Fission (binary and multiple), regeneration and fragmentation are considered as methods of asexual reproduction because all of them involve only one parent and gametes are not formed in them. New individuals produced after cell division are always genetically identical or clone to their parents.
A) The answer is allosteric interaction where activators or repressors bind to a protein, other than the protein active site, hence changing the protein conformation. This interaction occurs between the heme subunits of haemoglobin.
b) Through protonation. The amino group of the alpha subunits and the histidine C-terminal of beta subunits acquire H+ when the blood has low pH. Low pH in the blood is due to accumulation of carbon dioxide and consequent formation of carbonic acid. Protonation of the residues cause allosteric interaction, due to ionic interaction, of the subunits hence resulting to conformation change of haemoglobin between T-state and R-state
Crystalline silica is a natural compound in the earth's crust and is a basic component of sand and granite. Silicosis is an incurable disease of the lungs caused by breathing crystalline silica dust. This dust can cause scar tissue to form in the lungs.
