Lymphoid organs in the immune system, includes the bone marrow
He used a simple microscope
Answer:
c)polymerase chain reaction (PCR).
Explanation:
Because the paleontologist recovered only a bit of tissue and it is very old, it is very likely that the DNA in the sample is very small and part of it is degraded. Anyway, the paleontologist must first amplify the DNA sample to obtain many identical copies of the specific region of the DNA they want to compare. the above is done through a polymerase chain reaction (PCR).
Answer:
Swishing sound.
Explanation:
Human heart produces unique sound when blood flows from one chamber to the next chamber. The two main sounds produced by heart are lub abd dub sound.
The doctor's examine the Janetta's heart and told that she has incompetent right atrioventricular valve. The doctor must have heard the swishing sound after the closing of right atrioventricular valve. This sound is the direct indication of incompetent AV valve.
