Answer
The arm and base of microscope are connected with each other with help of inclination joint. which provide easiness to user during research analysis or other microscopic studies.
It has significant role in light and compound microscope that need light for visualization of examine sample. It also help in easy rotation during focusing toward light for better contrast.
Positive selection tests to see if the TCR of a T-lymphocyte can recognize and bind to an MHC molecule.
<h3>What is a T-lymphocyte?</h3>
A T-lymphocyte is a special type of immune cell that is generated inside the bone marrow.
The T-cell receptor (abbreviated as TCR) is a protein located on these immune T lymphocytes.
In conclusion, Positive selection identifies if the TCR of a T-lymphocyte can recognize and bind to an MHC molecule.
Learn more about T-lymphocytes here:
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Answer: B
Explanation: Because the Red shows activity
(4) organisms in a changing environment must adapt to acquire necessary traits and survive