Organ systems.
With analogies it helps to make sentences. Cells compose tissues, as organs compose organ systems.
False Because milk contains lactose; lactose intolerant people lack the lactase enzyme which hydrolyses lactose into glucose and galactose, meaning that they suffer a variety of symptoms.
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.
Answer:
In animal field studies, why do scientists usually try to work without making the animals aware that the humans are present? It is necessary to observe the animals without disturbing them. When a controlled experiment is not possible, why do scientists try to identify as many relevant variables as possible?