Microevolution Flashcards
What is microevolution
evolutionary change that occurs on a time scale of a a few-1000’s of generations. (We can study these evolutionary processes within our lifetime)
Common perception of evolution
a very slow process from simple to complex life forms
Evolutionary biologists use evolution to understand the ___ rather than ____
present, past
AIDS is (on a time scale)
the later stages of a disease cause by HIV
HIV is common in these types of people
Homosexuals (Africa and South/East Asia)Woman in sub-Sahara AfricaIntravenous drug users
Describe the lifecycle of HIV
1) HIV binds to CCR5 and CD4 on host and centers cell2) viral RNA performs REVERSE transcriptase to make viral DNA3)viral DNA inserts into host DNA4) vRNA goes through transcription/translation5)New virus particles form and move out of host
HIV targets ____ which comprises the _______ which then kills the host
The Helper T-cell, immune system
HIV/AIDS kills the host due to
Lack of immune system so any sickness can kill
Describe the number of T-cells vs time of HIV infection graph
1) Initial decline due to HIV killing T-cells2) T-Cell numbers increase greatly to counter and kill most of the HIV virus3) Then slowly declines due to not being able to fight HIV anymore (because it evolves)
What is the minimal number of Helper T-cells needed to fight off general infection
200
When doe AID symptoms begin?
When the number of T-cells goes under the minimal amt.
What was one of the first drugs developed to fight HIV/AIDs?
AZT
What step in the HIV lifecycle does AZT affect?
Reverse transcriptase
AZT is a base analogue, what does that mean?
Its an unnatural base that pretends to be Thymine during reverse transcriptase
Explain how AZT combats HIV
It inserts its analog base so during reverse transcriptase it processes the face base (Z) rather than T and terminates the process
