<h2>Phylogeny and virus</h2>
Explanation:
Human immune deficiency virus forms the major cause of AIDS(Acquired immune deficiency syndrome)
- Phylogenetic analyses have showed that chimpanzees were the original hosts for this class of viruses
- Four lineages of HIV have arisen due to the independent cross species transmission to humans and two of these transmissions may have been through gorillas
- Simian immunodeficiency viruses(SIV) are the closest relatives of HIV infecting wild type chimpanzees and gorillas in west central Africa
- 98% of HIV infections are caused by HIV-1 group M,the virus has a fast rate of evolution and must have circulated within the population of humans for many years
- First species found to be infected naturally were African green monkeys where prevalence of infection is high
- HIV-1 and HIV-2 form a distinct clade within the lentiviruses indicating that humans have acquired their infections from other primates
- Sooty mangabeys(monkey) in West Africa ere the source of HIV-2 strains and there must have been multiple mangabey to human cross species jump
- A virus related to HIV-1 was reported in the year 1989 and was found in two captive chimpanzees in Gabon
- In 1999 a example of SIV was found from a chimpanzee
- Transmission from chimpanzee to humans gave rise to M and N groups which probably occurred in the locations where closely related SIV strains were found
- Most SIV's infect monkey species whereas chimpanzees(like humans)are apes,it is observed that chimpanzees initially acquired SIV's from monkeys
- The opportunities for chimpanzee-or monkey-to-human host jumps have existed for hundreds or thousands of years and it is expected that such transmissions might have occurred in the past
When a new and aggressive species is introduced into an ecosystem, it may not have any natural predators or controls.
The "thing that hangs in the back of your throat is called a UVULA, its main function is to prevent food from entering your nasal cavity
Answer:
oxygen, carbon dioxide and magnetic field