Hello there.
<span>Regulation of the cell cycle is dependent upon cyclins and cyclin-dependent kinases. The key(s) that allows a cell to progress beyond the restriction point is (are)
</span><span>c. cyclin A and Cdk2.
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Provided that there's no diagram, most molecules have particular areas on the molecules, called the "active area" that act as a lock to a particular substrate's molecular structure, providing the key.
An enzyme's active area is only able to be "unlocked" by a certain substrate's "key".
<span>Age structure would help scientists determine if the problem exists with young or old dolphins.
The age structure shows the distribution of the ages of the individuals in a population. This not only shows the type of change taking place in the population (increasing, decreasing or staying the same) but also is able to help us relate problems to ages. By determining the which age group is more stressed, the scientists will be able to narrow down the causes of the stress and create more accurate hypotheses.
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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.
C. <span>The duodenum is a separate anatomic structure. It is the first part of the small intestine after the stomach. </span>
