Chloroplast has evolved from photosynthetic bacteria
<u>Answer</u>: Option b false
<u>Explanation</u>:
- Refrigerating or freezing foods <em>does not kill all or most of the bacteria</em> in the food as lowering the temperatures of the food only renders the microbes present in it <em>inactive</em>. As soon as the food is brought back to normal temperature, the microorganisms present in it become active again.
- The advantage of freezing food is only limited to the fact that once the food is frozen, all the microbes be it fungus, bacteria etc. become inactive and do not multiply and thus, freezing prolongs the shelf life of food, however once this food is thawed the micro organisms again become active and start multiplying and can easily cause food borne illness.
- So, the only way to kill the micro organisms present in the food is to cook the food to correct temperatures and not freezing.
Answer: Differentiation is the process by which unspecialized cells become specialized to carry out distinct functions. A stem cell is an unspecialized cell that can divide without limit as needed and can, under specific conditions, differentiate into specialized cells.
They help bring about chemical reactions.
