Lamarck vs. Darwin
Urban Evolution (Hawksbeard, Rats, Juncos)
Genetics & Punnett Squares
Antibiotic Resistance
Big‑Picture Evolution Concepts
100
Which scientist argued that organisms change because they want to improve a trait, and then pass that improvement to offspring.
Lamarck
100
Hawksbeard plants in cities evolve shorter, heavier seeds because of what environmental challenge.
habitat fragmentation / tiny soil patches
100
Two heterozygous rats (Rr × Rr) mate. What proportion of offspring are expected to be resistant?
Note: R= resistance to warfarin ; r= susceptible to warfarin
75%
100
Explain why antibiotic resistance increases in regions with high antibiotic use.
Antibiotics kill susceptible bacteria, leaving resistant ones to reproduce.
100
Which term describes how well an organism survives and reproduces in its environment
Fitness
200
Darwin said this mechanism explained why giraffe had long necks (where individuals with helpful traits leave more offspring).
Natural Selection
200
What type of genetic change allows a rat population to survive a warfarin environment?
A mutation in the VKORC1 gene
200
A resistant rat crossed with a susceptible rat produces 50% resistant offspring. What must the resistant parent’s genotype be?
Rr (heterozygous)
200
What trait does colonies that grow close to the antibiotic disc have?
antibiotic resistance mechanism
200
Natural selection requires what type of difference among individuals.
genetic variation
300
Lamarck said changes happen because organisms want or need them; Darwin said they happen because of natural variation. Which scientist's theory is the one supported by evidence today.
Darwin
300
UCSD juncos show shorter flight‑initiation distances. What selective pressure in cities likely favors this trait?
frequent human presence reducing the advantage of fleeing early
300
A trait is controlled by two alleles. If the environment changes so that the recessive phenotype becomes advantageous, what happens to allele frequencies over time?
The recessive allele increases due to natural selection
300
In a bacterial dish, the clear zone around an antibiotic disc forms.Why?
The antibiotic diffuses outward and kills nearby bacteria
300
A population of insects becomes darker after a volcanic eruption darkens the landscape. Identify the selective pressure.
Predation
400
A population of lizards moves to an island with only tall shrubs. According to Darwin, what must already exist in the population for longer‑legged lizards to become more common?
pre‑existing variation (genetic variation)
400
Explain why both resistant and non‑resistant VKORC1 alleles remain in some rat populations, even with poison present.
Heterozygous rats crossed with one another causes a 25% chance of the wildtype phenotype.
FUN FACT! There is actually negative pressures on both sides! Homozygous for the wildtype allele is susceptible to warfarin, and homozygous for the mutated allele causes poor vitamin k recycling (vitamin k deficiency) and severe bleeding.
400
A population of mice has a dominant allele B for black fur and a recessive allele b for brown fur. A scientist traps 200 mice and records 150 black and 50 brown individuals. She then captures two black mice from this population at random and breeds them in the lab.The pair produces one brown offspring in their first litter.
Based on this information, what are the most likely genotypes of the two black parent mice?
Bb × Bb
400
What type of reproduction occurs when an antibiotic resistant bacteria divide into two bacterium (daughter cells) which are also resistant
asexual reproduction (binary fission)
400
Explain why evolution acts on populations, not individuals.
Individuals don’t change their DNA in response to the environment, but populations shift in allele frequencies over generations
500
Explain why a bodybuilder’s increased muscle mass does not lead to more muscular children, using Darwin’s reasoning.
Acquired traits don’t affect gametes, so they aren’t inherited.
500
A city plant evolves thicker leaves to reduce water loss from heat‑absorbing pavement. Identify the adaptation type and the selective pressure.
Structural adaptation driven by the urban heat effects
500
Who does Mr. Perreault want to win the Stanley Cup?
GOLDEN KNIGHTS!!!!
500
A hospital isolates two bacterial strains. Strain A grows normally unless exposed to antibiotics, where it dies. Strain B grows slowly even without antibiotics but survives high antibiotic doses. After 50 generations in an antibiotic‑rich environment, Strain B dominates.
What evolutionary trade‑off explains why Strain B becomes more common?
Resistance carries a cost (slower growth), but under antibiotic pressure survival outweighs growth rate.
500
A population of fish moves into murky water. Over time, individuals with larger eyes become more common. Describe the full natural selection sequence (variation → selection → inheritance → population change).
Some fish already had larger eyes (through gamete mutations)→ they survived better → passed the trait on → population shifted toward larger eyes.