The answer is chloroplasts
Answer:
20 amino acids
Explanation:
500 amino acids have been identified in nature, but just 20 amino acids make up the proteins found in the human body.
When a horizontally positioned plant responds to gravity, then auxins in the lower sides of the stems cause cell elongation that bends the stem upright. The correct option among all the options that are given in the question is the first option. This action is mainly due to the nature of the plants to grow towards sunlight.
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:
brainly.com/question/17025187
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