5. parasitic life cycles

Question 1

what do some parasites require?

Answer 1

Some parasites require only one host to complete their life cycle

Question 2

what is malaria caused by?

Answer 2

The human disease malaria is caused by Plasmodium

Question 2

what do many parasites require?

Answer 2

Many parasites require more than one host to complete their life cycle

Question 3

what does a vector do?

Answer 3

A vector plays an active role in the transmission of the parasite and may also be a host

Question 4

what causes schistosomiasis?

Answer 4

Schistosomes cause the human disease schistosomiasis

Question 5

what are viruses?

Answer 5

Viruses are parasites that can only replicate inside a host cell

Question 6

what do viruses contain?

Answer 6

Viruses contain genetic material in the form of DNA or RNA, packaged in a protective protein coat

Question 7

what are viruses surrounded by?

Answer 7

Some viruses are surrounded by a phospholipid membrane derived from host cell materials

Question 8

what does the outer surface of a virus contain?

Answer 8

The outer surface of a virus contains antigens that a host cell may or may not be able to detect as foreign

Question 9

what is the viral life cycle?

Answer 9

infection of host cell with genetic material, host cell enzymes replicate viral genome, transcription of viral genes and translation of viral proteins, assembly and release of new viral particles

Question 10

what do RNA retroviruses use?

Answer 10

RNA retroviruses use the enzyme reverse transcriptase to form DNA, which is then inserted into the genome of the host cell

Question 11

what then happens to viral genes?

Answer 11

Viral genes can then be expressed to form new viral particles