What does the term “atomic operation” mean?

What part of the body is this image a cross-section from?      

What term describes structure B? (Hint: this image is from the male reproductive system and is responsible for producing testosterone)  

In reference to the feedback loop below, would it be considered a negative or positive feedback loop?  

The blood samples below have been treated with Anti-A, Anti-B, and Anti-D/Anti-Rh. What is the blood type of Blood sample 3?        

The blood samples below have been treated with Anti-A, Anti-B, and Anti-D/Anti-Rh. What is the blood type of Blood sample 2?        

In reference to the feedback loop below, would it be considered a negative or positive feedback loop?  

In the picture below, a nucleotide is indicated by the letter:

Consider the following image of a cell inside a solution:   The percentages represent the solute concentration of the cell and the solution respectively. The cell membrane is semipermeable, so water can move freely across the membrane, but solutes cannot. Use this to answer the following questions.

The ability to roll one’s tongue is a dominant trait. Say one parent is homozygous dominant for the trait crosses with one parent who is heterozygous. What are the chances their offspring cannot roll their tongue?