Question

gene expression quick check
gene expression is determined by several factors, including (1 point)
protein synthesis
senescence
chemicals in the body
the brain

Explanation:

Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. Protein synthesis is part of gene expression (it's the end - result where the gene product - usually a protein - is made). Senescence is the process of aging in cells and is not a direct factor in determining gene expression. The brain is an organ and not a direct factor in gene expression. Chemicals in the body, such as signaling molecules (hormones, transcription factors etc.) can bind to DNA or associated proteins and regulate whether a gene is expressed or not. For example, transcription factors (proteins which are chemicals in a sense) bind to promoter regions of genes and can either activate or repress gene transcription, which is a key step in gene expression.

Answer:

chemicals in the body