Middle School Life Science Flashcards: Measure Evolutionary Change

What this deck covers

This deck focuses on Measure Evolutionary Change, giving you a quick way to review the definitions, rules, and examples that matter most for Middle School Life Science.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What is the total number of allele copies for an autosomal gene in $N$ diploid individuals?

Answer: Total allele copies = $2N$. Each diploid individual has 2 copies of each autosomal gene.

Flashcard 2: What is genotype frequency, stated as a proportion?

Answer: Genotype frequency = $\frac{\text{individuals with genotype}}{\text{total individuals}}$. Proportion of individuals carrying a specific genotype combination.

Flashcard 3: What is relative fitness, stated as a ratio using survival or reproduction?

Answer: Relative fitness = $\frac{\text{avg offspring (or survival) of type}}{\text{avg offspring (or survival) of reference}}$. Compares reproductive success between types as a ratio.

Flashcard 4: Identify the survival proportion if $75$ of $300$ individuals survive to reproduce.

Answer: $\frac{75}{300}=0.25$. Survival rate as proportion of survivors to total.

Flashcard 5: Which statement best links proportional change in allele frequency to evolution?

Answer: Evolution occurs when allele frequencies in a population change across generations. Changing allele proportions over time defines evolution.

Flashcard 6: Identify the relative fitness if type X averages $6$ offspring and type Y averages $4$ offspring (Y is reference).

Answer: $\frac{6}{4}=1.5$. X produces 1.5 times more offspring than reference Y.

Flashcard 7: Identify the fold change when an allele frequency changes from $0.10$ to $0.25$.

Answer: $\frac{0.25}{0.10}=2.5$-fold. Divide final by initial frequency to get fold change.

Flashcard 8: Identify the proportional increase when an allele frequency changes from $0.10$ to $0.25$.

Answer: Increase of $0.15$. Subtract initial from final frequency: $0.25 - 0.10 = 0.15$.

Flashcard 9: Identify the percent allele frequency of $B$ if its proportion is $0.08$.

Answer: $8\%$. Convert proportion to percentage by multiplying by 100.

Flashcard 10: Identify the genotype frequency of $AA$ if $18$ of $60$ individuals are $AA$.

Answer: $\frac{18}{60}=0.30$. Direct proportion of AA individuals to total population.

Flashcard 11: Identify the allele frequency of $A$ if $A$ appears $30$ times in $50$ total allele copies.

Answer: $0.60$. $\frac{30}{50} = 0.60$ using the allele frequency formula.

Flashcard 12: Identify the allele frequency of $a$ in $20$ diploid individuals if there are $10$ copies of $a$.

Answer: $\frac{10}{40}=0.25$. 20 diploid individuals have 40 total allele copies.

Flashcard 13: Identify the expected count with proportion $0.30$ in a sample of $200$ individuals.

Answer: $0.30\times200=60$. Multiply proportion by sample size to get expected count.

Flashcard 14: Which statement correctly connects natural selection to proportions in a population?

Answer: Selection increases the proportion of alleles that improve survival or reproduction. Selection favors beneficial alleles, changing their proportions.

Flashcard 15: What is allele frequency in a population, stated as a proportion?

Answer: Allele frequency = $0\frac{\text{number of copies of the allele}}{\text{total allele copies for that gene}}$. Divides specific allele copies by total to get proportion.

Flashcard 16: Which option correctly interprets a population where allele $R$ changes from $0.40$ to $0.55$ in one generation?

Answer: Allele $R$ increased by $0.15$, indicating evolutionary change. Frequency change of 0.15 shows evolution occurred.

Flashcard 17: What is the definition of phenotype frequency?

Answer: Proportion of individuals in a population with a given trait. Counts individuals showing a trait divided by total population size.

Flashcard 18: Choose the correct proportional statement: if survivors are $12$ of $20$, what is survival rate?

Answer: $0.60$. Survival rate = survivors/total = rac{12}{20} = 0.60.

Flashcard 19: Calculate percent increase: a trait rises from $10\%$ to $15\%$. What is the relative increase?

Answer: $50\%$. Relative increase = rac{15-10}{10} imes 100% = 50%.

Flashcard 20: Calculate change: allele $A$ frequency goes from $0.20$ to $0.35$. What is $\Delta p$?

Answer: $0.15$. Change = final - initial = $0.35 - 0.20 = 0.15$.

Flashcard 21: Identify the total number of alleles counted at one gene in $N=40$ diploid organisms.

Answer: $80$. Diploid organisms have 2 alleles per gene, so $40 imes 2 = 80$.

Flashcard 22: Find allele frequency $q(a)$: $AA=12, Aa=6, aa=2$. What is $q$?

Answer: $0.25$. q = rac{2(2)+6}{2(20)} = rac{10}{40} = 0.25.

Flashcard 23: Find allele frequency $p(A)$: $AA=12, Aa=6, aa=2$. What is $p$?

Answer: $0.75$. p = rac{2(12)+6}{2(20)} = rac{30}{40} = 0.75.

Flashcard 24: Calculate percent: $18$ of $60$ beetles are green. What percent are green?

Answer: $30\%$. Percent = rac{18}{60} imes 100% = 30%.

Flashcard 25: Find and correct the proportional reasoning error: 'Because $30$ individuals changed, the population evolved.'

Answer: Correct: Evolution is a change in allele frequencies, not individuals. Evolution requires allele frequency changes, not just individual changes.

Flashcard 26: Identify the selection claim best supported by data: trait frequency rises from $0.40$ to $0.70$ in $5$ generations.

Answer: The trait likely increased fitness under those conditions. Large frequency increase suggests the trait improved survival/reproduction.

Flashcard 27: Calculate phenotype frequency: $18$ of $60$ beetles are green. What is the frequency of green?

Answer: $0.30$. Frequency = rac{18}{60} = 0.30 (part divided by total).

Flashcard 28: Identify the correct formula for percent of a group: part $x$ out of total $y$.

Answer: $\text{percent}=\frac{x}{y}\times 100\%$. Divide part by whole, then multiply by 100 to convert to percentage.

Flashcard 29: Which comparison best supports natural selection: changed allele frequencies in individuals or in populations?

Answer: In populations. Natural selection acts on individuals but evolution occurs in populations.

Flashcard 30: What does a change in allele frequency over generations indicate?

Answer: Evolution of the population. Evolution is defined as genetic change in populations over time.