A change in their food, from trees to grass in the Great Plains.
Answer:
It controls activities
Explanation:
X is the nucleus of the cell which is sometimes know as the 'brain' of the cell because it controls activities. It contains DNA that is needed to conduct most of the cell's functions.
Answer:
The secondary immune response is the immune response when the same antigen , memory cells that was encountered before is remembered and the immune system make antibodies to counter it.
Explanation:
There is a difference between the primary immune response and secondary immune response.
In the primary immune response occur when the immune system encountered an antigen for the first time which lead to the generation of memory cells and and the B cells with the T cells produce antibodies.
While the secondary immune response occur when the same antigen that was encountered the first time is encountered the second time and it lead to the stimulation of memory cells to produce more and high quantities of antibodies to fight foreign substances.
Answer:
Place a filter funnel on the top of a conical flask.
Roll the filter paper into a cone and place it on the flask.
Pour the mixture of sand and water into the conical flask with the filter funnel and paper.
Wait till all the sand is left over in the filter paper and all the water has been separated.
(You could also heat the sand in a warm oven to remove any water remaining)
