Answer:
D. The individuals differ greatly in physical attractiveness.
Explanation: just took the test and got it right.
Answer: For detection and confirmation of HIV antibodies in blood samples.
Explanation: As the name implies ELISA( Enzyme-linked immunosorbent assay) is the first test widely used for determining the presence of HIV in a person's serum because of its high sensitivity. In an ELISA, a person's serum is diluted 400 times and applied to a plate to which HIV antigens are attached. If antibodies to HIV are present in the serum, they may bind to these HIV antigens. The plate is then washed to remove all other components of the serum. A specially prepared "secondary antibody" (an antibody that binds to other antibodies) is then applied to the plate, followed by another wash. This secondary antibody is chemically linked in advance to an enzyme.
Thus, the plate will contain enzyme in proportion to the amount of secondary antibody bound to the plate. A substrate for the enzyme is applied, and catalysis by the enzyme leads to a change in color or fluorescence. ELISA results are reported as a number; the most controversial aspect of this test is determining the "cut-off" point between a positive and a negative result. A cut-off point may be determined by comparing it with a known standard. Unknown samples that generate a stronger signal than the known or control sample or are called "positive" while those that generate weaker signal are "negative".
Answer:
B
Explanation:
sphenoid bone is the answer.
Answer:
I. Unidirectional microphone.
II. Bidirectional microphone.
III. Omnidirectional microphone.
Explanation:
Sound are mechanical waves that are highly dependent on matter for their propagation and transmission.
Sound travels faster through solids than it does through either liquids or gases.
A microphone can be defined as an electrical device used for the conversion of sound energy into an electrical signal or energy.
The various forms of microphone include the following;
I. Unidirectional microphone: picks up sound from a specific direction.
II. Bidirectional microphone: picks up sound from two specific directions
III. Omnidirectional microphone: picks up sound from virtually any direction
