BIO GR 4

Question 1

What is microevolution?

Answer 1

Changes in allele frequencies within a population over generations (e.g., gene flow, genetic drift).

Question 2

What is macroevolution?

Answer 2

Large-scale evolutionary changes leading to new species (e.g., cetacean evolution).

Question 3

What are the requirements for natural selection?

Answer 3

1. Pre-existing variation 2. Heritability 3. Differential survival/reproduction.

Question 4

What is gene flow?

Answer 4

Transfer of alleles between populations via migration (e.g., Vietnam War orphans).

Question 5

What is genetic drift?

Answer 5

Random change in allele frequencies; includes bottleneck & founder effects.

Question 6

What is the bottleneck effect?

Answer 6

Population reduction → loss of genetic diversity (e.g., Pingelap typhoon).

Question 7

What is the founder effect?

Answer 7

Small group starts a new population (e.g., Amish Ellis-van Creveld syndrome).

Question 8

What is sexual selection?

Answer 8

Non-random mating drives traits (e.g., peacock tail feathers).

Question 9

What is fitness in evolutionary terms?

Answer 9

Reproductive success (number of viable offspring).

Question 10

What are homologous structures?

Answer 10

Shared ancestry, different functions (e.g., vertebrate limbs).

Question 11

What are analogous structures?

Answer 11

Similar function, different origins (e.g., bird vs. insect wings).

Question 12

What are vestigial structures?

Answer 12

Reduced/no function (e.g., human tailbone).

Question 13

What are molecular homologies?

Answer 13

Shared DNA/proteins (e.g., cytochrome c in humans/chimps).

Question 14

What characterizes Gram(+) bacteria?

Answer 14

Thick peptidoglycan layer (e.g., Staphylococcus).

Question 15

What characterizes Gram(-) bacteria?

Answer 15

Thin peptidoglycan + outer membrane/LPS (e.g., E. coli).

Question 16

What is the Kirby-Bauer test?

Answer 16

Measures antibiotic susceptibility via zones of inhibition.

Question 17

What is the zone of inhibition?

Answer 17

Area around antibiotic disc where bacteria don’t grow (larger = more effective).

Question 18

What is antibiotic resistance?

Answer 18

Pre-existing mutations + selection pressure (e.g., E. coli mutant strain).

Question 19

What is innate immunity?

Answer 19

Non-specific defenses (skin, phagocytes, inflammation).

Question 20

What is adaptive immunity?

Answer 20

Specific response with memory (B cells, T cells).

Question 21

What do B cells do?

Answer 21

Produce antibodies (neutralize pathogens).

Question 22

What do helper T cells do?

Answer 22

Activate B/T cells (CD4+).

Question 23

What do cytotoxic T cells do?

Answer 23

Kill infected cells (CD8+).

Question 24

What are memory cells?

Answer 24

Enable rapid secondary immune response.

Question 25

What is the vaccine principle?

Answer 25

Introduce antigens to trigger memory cells.

Question 26

What is herd immunity?

Answer 26

Population protection via high vaccination rates.

Question 27

What is acclimatization?

Answer 27

Short-term physiological adjustment (e.g., increased RBCs at high altitude).

Question 28

What is adaptation?

Answer 28

Long-term genetic change (e.g., Tibetan EPAS1 gene).

Question 29

What is lactose tolerance?

Answer 29

Natural selection example (dairy farming advantage).

Question 30

What is the challenge of an HIV vaccine?

Answer 30

Rapid mutation, hides in host DNA, targets CD4+ T cells.