The answer is B, bird flu. The other diseases have been around much longer than bird flu has. Bird flu has been in Asia since 2003, but didn't reach Europe and the middle east until 2005, making bird flu a very new disease.
Answer: Meiosis is a process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell. Meiosis usually involves two distinct divisions, called meiosis I and meiosis II. By the end of meiosis II, the diploid cell becomes four haploid cells.
Explanation:
Answer:
False
Explanation:
In the troposphere, near the Earth's surface, human activities lead to ozone concentrations several times higher than the natural background level. Too much of this ground-level ozone is 'bad' as it is harmful to breathe and also damages vegetation.
The stratosphere or “good” ozone layer extends upward from about 6 to 30 miles and protects life on Earth from the sun's harmful ultraviolet (UV) rays.
