(D)an atom can join with other kinds of atoms.
Basically he explained what a molecule is.
Answer:
$400
Explanation:
This is a simple multiplication question.
200kWh × $2/kWh = $400/200kWh
We are worried about the top number, because that is how much it costs the family to use 200kWh of electricity each month.
Final answer: $400 for 200kWh.
Small leaves protect desert plants from animals that eat plants.
The correct answer is that "the T cell enters a state of anergy".
The activation of T cells requires two signals: (1) antigen specific signal presented by an antigen presenting cell (either a macrophage or a dendritic cell) that activates t cell receptors and (2) co-stimulatory signals that is not antigen specific but rather found in the plasma membrane of the antigen presenting cell (i.e. CD28). In the absence of a co-stimulatory signal, the t cell will enter a state of anergy or the inability to produce an immune response toward an offending antigen.
