Answer:
The four nitrogen bases that are found in deoxyribonucleic acid (DNA) are adenine, cytosine, guanine, and thymine.
Thymine and cytosine comprise of one -carbon nitrogen ring and also called pyrimidines, while two carbon nitrogen ring is present in adenine and guanine and also called purines. Purines has larger in size because of extra carbon nitrogen ring.
Do you have any choice answers? As far as I know, the organisms that appeared first was micro-organisms. Hope this helps.
The correct answer is D. Bird flu.
Polio and smallpox are very rare today as they were eradicated hundreds of years ago and TB has been around for maybe thousands of years. Bird f!u was discovered in 1957.
Answer:
By age group, in 2019, the number of new HIV diagnoses was highest among people aged 25 to 29. From 2015 through 2019, HIV diagnoses increased among persons aged 13-24 years, 35-44 years, and 45-54 years.