He had a bacterial infection, but then developed an allergy to the antibiotic.
The correct answer is B. Oxygen.
Oxygen, as a part of the atmosphere, also participates in UV protection, besides being necessary for breathing.
The process of DNA replication occurs just before S phase. In the interphase, the cell has growth and replication of DNA is getting made. In the G1 phase, there is the growth, (G1-checkpoint - cell size, growth, environment shows cell is ready to start replicating DNA. S phase- DNA is replicated.
Explanation:
It stretched or compresses the sound waves it is producing if it is relatively moving away to getting closer respectively. This is called the <u>Doppler shift effect</u>..
This is why when a wailing ambulance approached you, the pitch of its wailing is high but when it passes you and moves away from you the pitch of the wailing lowers. Remember this is happening relative to your position.
It is a vestigial Structure.
Explanation: