Answer:
CD40L
Explanation:
The CD40 ligand (CD40L) protein is a transmembrane glycoprotein which is expressed on activated T cells and belongs to the tumor necrosis factor (TNF) superfamily. The hyper IgM syndrome is caused by mutations in the CD40L gene, where the defective protein can no longer bind CD40 on antigen-presenting cells. The X-linked Hyper IgM syndrome is characterized by abnormal levels of immunoglobulins, i.e., low levels of IgG and IgA, and increased/normal levels of IgM. Because CD40L gene is located on the X chromosome, this disorder is observed much more frequently in males than in females.
that layers of sediment were originally deposited horizontally under the action of gravity
The answer is a “rises because it is less dense than cold air”
