Why Does It Take More Than a Week Before a Mosquito

question 39

Multiple Choice

Why does it take more than a week before a mosquito just infected with yellow fever virus can transmit the disease?

• A)The virus must replicate in the gut of the mosquito before it can reach high enough numbers for transmission to a new human.
• B)Mosquitoes only feed once a week,which limits their ability to transmit the disease rapidly.
• C)Yellow fever is caused by a protozoan.It must develop from the sporozoite form into the mature form to become infectious,and this takes time.
• D)The virus multiplies in the gut of the mosquito,but then needs to migrate to the proboscis (biting nose)of the animal in order to infect a new human being after a new bite.This migration takes time.

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Greater Percentage

A proportion or share expressed as a fraction of 100 that is larger relative to a comparison figure or within a total.

Gross Investment

Total amount spent on new capital assets without deductions for depreciation.

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