Microevolution Flashcards Preview

Recovered From Flashcardlet > Microevolution > Flashcards

Flashcards in Microevolution Deck (32):
2

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)

3

Common perception of evolution

a very slow process from simple to complex life forms

4

Evolutionary biologists use evolution to understand the ___ rather than ____

present, past

5

AIDS is (on a time scale)

the later stages of a disease cause by HIV

6

HIV is common in these types of people

Homosexuals (Africa and South/East Asia)Woman in sub-Sahara AfricaIntravenous drug users

7

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

8

HIV targets ____ which comprises the _______ which then kills the host

The Helper T-cell, immune system

9

HIV/AIDS kills the host due to

Lack of immune system so any sickness can kill

10

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)

11

What is the minimal number of Helper T-cells needed to fight off general infection

200

12

When doe AID symptoms begin?

When the number of T-cells goes under the minimal amt.

13

What was one of the first drugs developed to fight HIV/AIDs?

AZT

14

What step in the HIV lifecycle does AZT affect?

Reverse transcriptase

15

AZT is a base analogue, what does that mean?

Its an unnatural base that pretends to be Thymine during reverse transcriptase

16

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

17

How many years of life does AZT add?

1-3 years

18

Why does AZT stop working

The virus evolved to make sure it uses T

19

How does HIV counter AZT so rapidly?

1) High mutation rate2) Fast generation time (2.6 days)All in all, high evolution rate

20

What permits HIV to persist at LOW levels in the body

Its high mutation rate (sorta stays incognito until its evolved enough to attack)

21

HIV's high mutation rate allows it to exist at _______ levels, keeping 1 step ahead of the immune system

Low levels, (and gradually builds up)

22

What is the Escape Hypothesis?

1) the number of evolving HIV genotypes increases with time2) The immune system works hard to keep up with all the new genotypes3) Immune system becomes overwhelmed and fails to protect the body

23

HIV is a devastating disease because of its

EVOLUTIONARY POTENTIAL AHHH!

24

HIV's evolutionary rate reflects the process of _____ and ___ as well to ___ and ____

Pests and bacteria to pesticides and anti-biotics

25

To reduce anitbiotic resistance

Reduce unnecessary use of them to slow evolution resistance

26

Why is it good to reduce the use of antibiotics in non-dire situations?

It reduces the resistance to antibiotics

27

What is a pandemic

a disease that spreads worldwide

28

Each pandemic is due to...

the evolution of a radically new viral genotype

29

Most influenza strains originate in

wild birds

30

Explain the process of double infection

When two viruses from two different species infect the same species (bridge)

31

What does a hybrid virus stem from?

A double infection in a species

32

Give an example that involves double infection and hybrid virus

Bird influenza and human virus both infect livestock and the viral genes come together to make a hybrid virus and everyone is vulnerable to infection

33

The creation of the hybrid virus leads to the start of a ____

pandemic