One explanation could be the differences in climate (environmental factors). The climate in northern Mexico could support the reproduction of the mosquito species, which is a vector of the dengue virus. Other environmental conditions that influence its endemicity could include living conditions and sanitation. The other possiblity could be that the people in the US have developed immunity for the disease, therefore, are unaffected even when infected by the virus.
Answer:the correct option is B
(Streptococcus).
Explanation:
Acute necrotizing ulcerative gingivitis (ANUG) occurs due to poor oral hygiene which encourages plaque to form on teeth, causing inflammation of the surrounding gum tissues. The microorganisms that are known to inhabit the damaged tissues are oral spirochaete which includes Borrelia,Fusobacteria, Bacteroidese and Peptostreptococcus. Streptococcus is not an oral spirochaete therefore is excluded. I hope this helps.
Answer:
D
Explanation:
A substitution is where a base is substituted by another base
A. ATGAT - this is not a substitution, the C has been <u>deleted</u>
B. UAGCUA - this is not a substitution, but is the complementary mRNA sequence (you can tell because there are Us instead of Ts)
C. TAGCTA - this is not a substitution, but is the complementary DNA sequence
D. ATGGAT - this is a substitution, the C in the original sequence has been replaced (substituted) by a G.
