In the Microarray Shown in the Textbook (P

question 25

Multiple Choice

In the microarray shown in the textbook (p. 414) , the cDNAs were labeled with red and green fluorescent tags. Why do some spots on the microarray emit yellow light?

• A) Red and green are two of the primary colors, and if both cDNAs hybridize to the spot, the combination of the two will produce yellow light.
• B) The yellow light comes from the laser, and a yellow spot indicates that neither cDNA hybridized to that spot on the microarray.
• C) The over-expression of one cDNA relative to the other will skew the color pattern of the spot on the microarray, resulting in the yellow color.
• D) The color choice was an arbitrary decision by the artist and doesn't reflect how the process actually works.
• E) Yellow spots are those that contain no DNA probes on the chip.

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Definitions:

Implantation

The process by which a fertilized egg attaches to the lining of the uterus, beginning the stages of pregnancy.

Chorionic Villi

Finger-like projections from the chorion that extend into the uterine wall, facilitating nutrient exchange between mother and fetus.

Syncytiotrophoblast

Outer layer of the trophoblast composed of multinucleated cells.

Amniotic Cavity

A fluid-filled sac that encloses and protects the developing fetus in the uterus.