Measure Evolutionary Change - Middle School Life Science

1. Calculate the change in proportion: trait is $0.20$ in Gen 1 and $0.35$ in Gen 2. What is $\Delta p$?

   $0.15$. $0.35 - 0.20 = 0.15$ shows the change between generations.

2. Identify $\Delta p$: allele frequency is $0.25$ in Gen 1 and $0.40$ in Gen 2. What is $\Delta p$?

   $0.15$. $0.40 - 0.25 = 0.15$ shows frequency increased.

3. What is the formula for a proportion used to compare trait frequencies?

   $\frac{\text{part}}{\text{whole}}$. Basic ratio formula for comparing frequencies in populations.

4. What is the percent of individuals with a trait if $12$ of $48$ show the trait?

   $25\%$. Divide individuals with trait by total, then multiply by 100.

5. What is the definition of mutation in evolutionary change?

   A DNA change that can introduce new alleles into the population. Creates genetic variation that natural selection can act upon.

6. What is the definition of phenotype frequency?

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

7. What is the allele frequency of allele A if $30$ of $100$ alleles in a population are A?

   $0.30$. Divide the number of A alleles by the total number of alleles.

8. What relationship between allele frequencies must be true for a two-allele gene?

   $p+q=1$. All alleles must sum to 100% of the gene pool.

9. Identify the allele-frequency change if $f(A)$ goes from $0.60$ to $0.48$.

   Decrease of $0.12$. $0.48 - 0.60 = -0.12$ (a decrease)

10. Identify the proportion if $45\%$ of individuals show a trait.

    $0.45$. Convert percent to decimal by dividing by 100.

11. What is the average change per generation if allele frequency changes from $0.10$ to $0.25$ over $5$ generations?

    $0.03$ per generation. Total change ÷ generations: $\frac{0.25-0.10}{5} = 0.03$.

12. Identify the proportion of allele $A$ if there are $30$ $A$ alleles and $70$ $a$ alleles.

    $p=\frac{30}{100}=0.30$. Divide $A$ count by total count to find the proportion.

13. What is the correct proportion statement to compare trait frequencies between two populations?

    Compare $$trait count$ total$ for each population. Calculate frequency as a ratio for standardized comparison.

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

    $0.30$. Frequency = $\frac{18}{60} = 0.30$ (part divided by total).

15. Identify the allele frequency of $a$ if $Aa=12$, $aa=8$, and $AA=20$ in a diploid population.

    $(12+28) (240) = 28 80 = 0.35$. Count all $a$ alleles: $12$ from $Aa$ plus $16$ from $aa$, then divide by total.

16. Identify the proportion for allele $A$ if $30$ of $100$ total alleles are $A$.

    $0.30$. Calculate $\frac{30}{100} = 0.30$ to find the proportion.

17. What is the formula for percent of a trait if $x$ individuals show it out of $n$ total?

    $\text{percent}=\frac{x}{n}\times 100\%$. Divides trait count by total and multiplies by 100 for percentage.

18. What is the definition of natural selection in terms of proportional reproductive success?

    Individuals with advantageous traits leave a higher proportion of offspring. Better-adapted organisms produce more offspring relative to others.

19. What is the definition of allele frequency in a population using proportional reasoning?

    Allele frequency = $$number of an allele$ total alleles in the gene pool$. Counts specific alleles divided by total alleles to find their relative frequency.

20. Identify the change in trait proportion from $0.20$ to $0.35$ over generations.

    Increase of $0.15$ (15 percentage points). Subtract initial from final: $0.35 - 0.20 = 0.15$

21. Identify the correct proportion for allele $A$ if there are $30$ $A$ alleles out of $100$ total alleles.

    $30 100 = 0.30$ (30%). Divide count of A alleles by total alleles to get frequency.

22. Which measure is best for comparing traits across populations of different sizes: counts or proportions?

    Proportions (percentages) are best. Proportions allow fair comparison regardless of population size.

23. Find and correct the error: "Evolution occurred because the number of resistant insects increased from $20$ to $30$."

    Correct: show a proportion increase (frequency) across generations. Evolution requires frequency change, not just count change.

24. Identify the number with a trait in a population of $500$ if frequency is $8\%$.

    $40$ individuals. $500 \times 0.08 = 40$ individuals

25. What is the fold change in frequency if a trait rises from $0.10$ to $0.25$?

    $2.5\times$. Fold change = new frequency ÷ old frequency: $\frac{0.25}{0.10}$.

26. What is the definition of selection pressure in evolution?

    An environmental factor that changes survival or reproduction proportions. Affects which individuals survive and reproduce more successfully.

27. A trait rises from $12$ of $80$ to $30$ of $100$. What are the two proportions (old, new)?

    Old $= \frac{12}{80} = 0.15$; New $= \frac{30}{100} = 0.30$. Calculate each proportion by dividing trait count by total.

28. Which proportional pattern best supports selection against a trait over time?

    The trait's proportion decreases over generations. Declining proportions indicate negative selection pressure.

29. What is the proportion form of a percent $p\%$ expressed as a frequency?

    Proportion = $\frac{p}{100}$. Divide percent by 100 to convert to decimal proportion.

30. Identify the survival proportion if $45$ of $60$ individuals survive a drought.

    $\frac{45}{60}=0.75$ (75%). Divide survivors by initial population for survival rate.

31. What is the survival rate if $90$ of $120$ individuals survive to reproduce?

    $0.75$. Survivors divided by initial population: $\frac{90}{120} = 0.75$.

32. Calculate the proportion with trait A: $18$ of $60$ beetles are green. What is the proportion?

    $0.30$. $\frac{18}{60} = 0.30$ by dividing part by whole.

33. What is the percent change formula for a trait frequency changing from $f_1$ to $f_2$?

    $\frac{f_2-f_1}{f_1}\times 100\%$. Standard formula: (new - old)/old × 100%.

34. Identify the stronger evidence of evolution: count rises from $10$ to $20$ or frequency rises from $0.10$ to $0.20$?

    Frequency rise from $0.10$ to $0.20$. Frequency change shows evolution; count change could be from population growth.

35. What is the definition of phenotype frequency using proportional reasoning?

    Phenotype frequency = $$number with a trait$ total individuals$. Counts individuals showing trait divided by total population.

36. Identify the relative increase when a trait rises from $10\%$ to $15\%$.

    $50\%$ relative increase. $\frac{15\% - 10\%}{10\%} \times 100 = 50\%$ increase

37. What is the allele frequency of allele a if $70$ of $100$ alleles in a population are a?

    $0.70$. Divide the number of a alleles by the total number of alleles.

38. What is the definition of allele frequency in a population?

    Proportion of all alleles at a gene locus that are a given allele. Measures how common one allele is compared to all alleles at that gene location.

39. What is the new frequency if a trait rises from $0.20$ to $0.35$? State the change $\Delta f$.

    $0.15$. Change in frequency is final minus initial: $0.35 - 0.20 = 0.15$.

40. What does it indicate if an allele's proportion increases from one generation to the next?

    Evolutionary change is occurring in that population. Rising allele frequencies indicate the population is evolving.

41. Identify the correct claim: Trait frequency drops from $0.70$ to $0.55$ after a drought. What happened?

    The trait became less common; selection likely acted against it. Decreasing frequency suggests negative selection pressure.

42. In a diploid population of $50$ individuals, how many total alleles exist for one gene?

    $100$ alleles. Each diploid individual has 2 alleles: $50 \times 2 = 100$.

43. Identify the allele frequency $q$ if $AA=16$, $Aa=8$, and $aa=1$ individuals are observed.

    $q=\frac{2(1)+8}{2(25)}=\frac{10}{50}=0.20$. Count all $a$ alleles (2 per $aa$, 1 per $Aa$) and divide by total.

44. Identify the expected count with proportion $0.30$ in a sample of $200$ individuals.

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

45. Choose the correct conclusion if a trait drops from $0.60$ to $0.45$ after a new predator appears.

    The trait likely reduces survival; selection may be acting against it. Frequency drop after predator arrival suggests trait decreases survival.

46. Which proportional comparison best supports evolution: change in individual size or change in allele frequency over generations?

    Change in allele frequency over generations. Evolution is measured by genetic changes, not individual changes.

47. Identify the fold change when an allele frequency changes from $0.10$ to $0.25$.

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

48. What is the definition of allele frequency in a population?

    Proportion of all alleles at a gene locus that are a given allele. Measures how common one allele is compared to all alleles at that gene.

49. What is the absolute change in allele frequency if $p$ goes from $0.55$ to $0.40$?

    $-0.15$. Absolute change = final - initial = $0.40 - 0.55 = -0.15$.

50. In $80$ diploid individuals, $52$ are $AA$, $24$ are $Aa$, $4$ are $aa$; what is $q$ for allele $a$?

    $0.20$. Count $a$ alleles: $(4 \times 2) + 24 = 32$; then $\frac{32}{160} = 0.20$.

51. Which term describes new alleles entering a population and potentially changing proportions?

    Mutation. DNA changes create new genetic variants that alter allele frequencies.

52. What is the percent form of a frequency $f$ expressed as a proportion?

    Percent = $f \times 100\%$. Multiply frequency by 100 to convert to percentage.

53. Calculate the trait proportion if $45$ out of $200$ organisms show the trait.

    $0.225$. $\frac{45}{200} = 0.225$

54. What is the allele frequency of allele a if $18$ of $60$ alleles in a population are a?

    $0.30$. Divide number of a alleles by total alleles: $\frac{18}{60} = 0.30$.

55. Find the trait frequency if $18$ of $60$ individuals show the trait.

    $\frac{18}{60} = 0.30$. Divide trait count by total to get frequency as decimal.

56. Which option shows stronger evidence of selection: allele frequency stays $0.50$, or shifts to $0.65$?

    Shift to $0.65$. Changing frequency indicates selection pressure acting on alleles.

57. Identify the correct percent formula for a trait in a population.

    $\frac{\text{count with trait}}{\text{total count}}\times 100\%$. Converts trait frequency to percentage by multiplying by 100.

58. Calculate the trait percent if $18$ out of $60$ organisms show the trait.

    $30\%$. $\frac{18}{60} \times 100\% = 30\%$

59. What is the total number of alleles in a diploid population of $80$ individuals for one gene?

    $160$ total alleles. Each diploid has 2 alleles, so $80 \times 2 = 160$.

60. Identify the best proportional evidence for evolutionary change: same trait counts, or different trait proportions over time?

    Different trait proportions over time. Proportions reveal relative changes even if population size varies.

61. In $100$ individuals, $20$ are $AA$, $50$ are $Aa$, $30$ are $aa$; what is $q$ (a allele frequency)?

    $0.55$. $q = \frac{2(30)+50}{2(100)} = \frac{110}{200} = 0.55$.

62. Identify the correct proportional reasoning statement: $15$ of $50$ is what percent?

    $30\%$. $\frac{15}{50} \times 100 = 30\%$.

63. In a diploid population of $50$ individuals, how many total alleles exist at one gene locus?

    $100$ total alleles. Each diploid individual has 2 alleles: $50\times 2=100$.

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

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

65. What is the definition of a proportion (in data about traits in a population)?

    A part-to-whole ratio, often written as $ p= \frac{\text{part}}{\text{whole}}$. Compares a subset to the total, expressed as a fraction.

66. Which ratio best compares two phenotypes: $24$ striped and $6$ solid individuals?

    $4:1$. Simplify $24:6$ by dividing both by 6 to get $4:1$.

67. Which expression gives genotype frequency for a genotype with count $G$ in a population of $N$ individuals?

    $\text{frequency}=\frac{G}{N}$. Genotype frequency equals genotype count over total individuals.

68. What is natural selection (in one sentence) in terms of proportions?

    Individuals with advantageous traits leave more offspring, increasing trait proportions. Differential survival and reproduction shift trait frequencies.

69. Identify the allele frequency $p$ if $A$ alleles = $30$ out of $100$ total alleles.

    $p=0.30$. Divide A alleles by total: $\frac{30}{100}=0.30$.

70. What does a change in allele frequency over generations indicate?

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

71. Find allele A count given $p=0.25$ in a diploid population of $40$ individuals.

    $0.25\times 80=20$ A alleles. Total alleles = $40\times 2=80$; A alleles = $0.25\times 80=20$.

72. A population has $120$ total alleles for gene A. If $36$ are allele $a$, what is the allele $a$ frequency?

    $\frac{36}{120} = 0.30$. Divide specific allele count by total alleles for frequency.

73. Which term describes a random change in allele proportions due to chance events?

    Genetic drift. Random sampling effects change allele frequencies by chance alone.

74. Which comparison best supports natural selection: changed allele frequencies in individuals or in populations?

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

75. Identify the relative fitness of type A if A leaves $6$ offspring and best type leaves $8$.

    $\frac{6}{8}=0.75$. Divide A's offspring by best type's offspring.

76. If $p=0.70$ for allele $A$, what is $q$ for allele $a$ assuming only two alleles ($p+q=1$)?

    $0.30$. Since $p + q = 1$, then $q = 1 - 0.70 = 0.30$.

77. What is the total number of allele copies for an autosomal gene in $N$ diploid individuals?

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

78. Calculate the frequency of a trait if $18$ of $60$ individuals show it.

    $18 60 = 0.30$ (30%). Divide individuals with trait by total individuals for frequency.

79. Identify the percent with a trait if $18$ of $60$ individuals have it.

    $30\%$. $\frac{18}{60} \times 100 = 30\%$

80. Which statement best describes microevolution in terms of proportions over generations?

    A change in allele frequencies (proportions) in a population over time. Evolution at population level measured by shifting allele proportions.

81. Which statement correctly defines evolution in a population using proportional reasoning?

    A change in allele frequencies over generations. Evolution means allele proportions shift across generations.

82. Identify the survival proportion if $75$ of $300$ individuals survive to reproduce.

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

83. Identify the allele frequency $q$ if $a$ alleles = $18$ out of $60$ total alleles.

    $q=0.30$. Divide a alleles by total: $\frac{18}{60}=0.30$.

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

    $0.75$. $p = \frac{2(12)+6}{2(20)} = \frac{30}{40} = 0.75$.

85. Which scenario indicates higher fitness: type X leaves $4$ offspring on average, type Y leaves $2$?

    Type X has higher fitness. More offspring means higher reproductive success and fitness.

86. Calculate the percent with trait A: $18$ of $60$ beetles are green. What percent is green?

    $30\%$. $\frac{18}{60} \times 100 = 30\%$ using the percent formula.

87. Which calculation correctly finds trait frequency: $\frac{\text{with trait}}{\text{total}}$ or $\frac{\text{total}}{\text{with trait}}$?

    $\frac{\text{with trait}}{\text{total}}$. Trait frequency equals individuals with trait over total.

88. Which change best indicates evolution in a population across generations: allele frequency or individual change?

    Allele frequency change in the population. Evolution occurs at population level through changing allele proportions.

89. Identify the absolute change in allele frequency if $p$ goes from $0.55$ to $0.40$.

    $0.40-0.55=-0.15$. Subtract initial from final frequency for absolute change.

90. Identify the missing allele frequency $q$ if $p=0.12$ for a two-allele gene.

    $q=1-0.12=0.88$. Since $p+q=1$, subtract $p$ from 1 to find $q$.

91. Identify the change in allele frequency if $p$ goes from $0.40$ to $0.55$.

    $\Delta p=+0.15$. Subtract initial from final: $0.55-0.40=+0.15$.

92. What is the allele frequency of allele A if $40$ of $100$ alleles in a population are A?

    $0.40$. Divide number of A alleles by total alleles in the population.

93. If survivors have trait frequency $0.70$ but the original population had $0.40$, what is the direction of selection on the trait?

    Selection favored the trait (positive selection). Higher frequency in survivors than original shows positive selection.

94. Calculate the percent with a trait: $18$ out of $60$ individuals show it. What percent is this?

    $30\%$. $\frac{18}{60} = 0.30 = 30\%$

95. What is the definition of phenotype frequency in a population?

    Proportion of individuals in a population with a given trait. Counts how many individuals show a trait out of the total population.

96. What is the formula for allele frequency of allele $A$ if there are two alleles $A$ and $a$?

    $f(A)=\frac{\#A}{\#A+\#a}$. Count of $A$ alleles divided by total alleles in gene pool.

97. Identify the allele $A$ count if a population has $200$ total alleles and $p=0.35$.

    $A=p \times 200=0.35 \times 200=70$. Multiply total alleles by frequency to get count.

98. Identify the best evidence of evolutionary change using proportions across generations.

    A consistent change in allele or trait proportions from one generation to the next. Evolution occurs when proportions shift over time, not randomly.

99. What is the definition of gene flow using proportional reasoning language?

    Movement of alleles that changes allele proportions between populations. Migration transfers alleles and alters population frequencies.

100. What is meant by "fitness" in evolution when comparing proportions of offspring?

     Relative reproductive success measured by average number of viable offspring. Higher fitness means producing more surviving offspring than others.

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

     $0.25$. $q = \frac{2(2)+6}{2(20)} = \frac{10}{40} = 0.25$.

102. What does it indicate about evolution if allele frequencies stay constant across generations?

     No evolutionary change is occurring in that population for that gene. Constant frequencies mean no selection pressure changing allele proportions.

103. What is the phenotype proportion if $18$ out of $60$ individuals have a trait?

     $0.30$. Calculate $\frac{18}{60} = 0.30$ for the proportion.

104. If $18$ of $120$ individuals survive, what is the survival proportion?

     $0.15$. Divide survivors by total population: $\frac{18}{120} = 0.15$.

105. Which option correctly defines relative fitness using proportional reasoning?

     Reproductive success compared as a ratio to others in the population. Fitness compares reproductive output between individuals as a ratio.

106. What is genotype frequency, stated as a proportion?

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

107. Identify the direction of change: allele A is $0.70$ then $0.55$. Did it increase or decrease?

     Decrease. $0.70$ to $0.55$ is a reduction of $0.15$.

108. Calculate the resistant allele frequency if resistant alleles rise from $25$ of $200$ to $60$ of $200$.

     From $0.125$ to $0.30$ (increase of $0.175$). Initial: $\frac{25}{200}=0.125$; Final: $\frac{60}{200}=0.30$; Change: $0.175$.

109. What is the formula for allele frequency of allele $A$ if counts are $A$ and $a$ alleles?

     $p=\frac{A}{A+a}$. Divide $A$ alleles by total alleles to get the proportion.

110. Which proportional pattern best supports evolution by selection: random up-down changes or steady increase in a beneficial trait?

     A steady increase in the beneficial trait frequency over generations. Consistent directional change indicates selection, not random drift.

111. What is the formula for percent of a phenotype if $n$ show it out of $N$ total?

     $\text{percent}=\frac{n}{N}\times 100\%$. Converts fraction to percentage by multiplying by 100.

112. What is allele frequency in a population, expressed as a proportion?

     Number of a given allele divided by total alleles for that gene. Expresses frequency as a ratio to compare across populations.

113. Identify the percent decrease if a trait drops from $50\%$ to $40\%$.

     $20\%$ decrease. Calculate $\frac{50-40}{50}\times 100\%=20\%$ decrease.

114. Identify $f(A)$ if a gene pool has $70$ copies of $A$ and $30$ copies of $a$.

     $0.70$. $\frac{70}{70+30} = \frac{70}{100} = 0.70$

115. What is the formula for allele frequency of allele $A$ if counts are $A$ and $a$ alleles?

     $p(A)=\frac{A}{A+a}$. Divides count of A by total alleles to get proportion.

116. What is the formula for percent of a trait in a population?

     $\text{percent}=\frac{\text{number with trait}}{\text{total number}}\times100$. Multiply the fraction by 100 to convert to percentage.

117. Which statement best links proportional change in allele frequency to evolution?

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

118. Identify the correct proportion for the fraction of individuals that carry a trait.

     \frac{\text{# with trait}}{\text{total individuals}}. Standard proportion formula for trait frequency in a population.

119. Identify the correct formula for allele frequency of A using counts: $p = \frac{\#A}{\#A + \#a}$ or $p = \frac{\#A}{N}$?

     $p = \frac{\#A}{\#A + \#a}$. Count of A alleles divided by total alleles (A plus a).

120. What does allele frequency mean in a population?

     Proportion of all alleles that are a specific allele. Calculated as count of specific allele divided by total allele count.

121. Which statement best links proportional data to natural selection: frequency of a trait increases after a pressure?

     The trait likely increased fitness under that selective pressure. Natural selection favors traits that increase survival/reproduction.

122. Identify the proportion with a trait if $45$ of $200$ individuals have it.

     $0.225$. $\frac{45}{200} = 0.225$

123. What is the definition of allele frequency in a population?

     The proportion of all alleles at a gene locus that are a given allele. Measures how common one version of a gene is compared to all versions.

124. Which option is the correct proportional statement for natural selection favoring a trait?

     The favored phenotype's proportion increases across generations. Selection increases the frequency of beneficial traits over time.

125. Identify the correct conclusion if phenotype proportion shifts from $10\frac{1}{2}$% to $21$%.

     The phenotype became more common (its proportion increased). The proportion doubled, showing the phenotype spread in the population.

126. What is the definition of genotype frequency in a population?

     Proportion of individuals in a population with a specific genotype. Measures how many individuals carry a specific gene combination.

127. In $80$ diploid individuals, $52$ are $AA$, $24$ are $Aa$, $4$ are $aa$; what is $p$ for allele $A$?

     $0.80$. Count $A$ alleles: $(52 \times 2) + 24 = 128$; then $\frac{128}{160} = 0.80$.

128. What is the selection rate for a trait, written as a proportion?

     Selection rate = \frac{\text{# survivors with trait}}{\text{# starting with trait}}. Measures survival rate as a proportion of initial trait carriers.

129. What is meant by allele frequency in a population?

     The proportion of all alleles that are a specific allele. It's the fraction of that allele type out of all alleles for that gene.

130. Identify the proportional increase when an allele frequency changes from $0.10$ to $0.25$.

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

131. Identify the correct proportional statement: if a trait is $25\%$ in Gen 1 and $50\%$ in Gen 2, how did it change?

     It doubled (increased by a factor of $2$). $\frac{50\%}{25\%} = 2$, so the proportion doubled.

132. Identify the ratio that best compares survival of two phenotypes with $s_1$ and $s_2$ survivors.

     $\text{survival ratio}=\frac{s_1}{s_2}$. Compares survival by dividing one group's survivors by the other's.

133. What does it mean to say a trait is more common in a population?

     A higher proportion of individuals show the trait. More individuals out of the total population express that trait.

134. Compute survivors percent: $40$ of $50$ insects survive pesticide. What percent survived?

     $80\%$. $\frac{40}{50} \times 100 = 80\%$ survived.

135. Calculate the change in allele frequency: $p$ goes from $0.40$ to $0.55$. What is $\Delta p$?

     $\Delta p=0.15$. Subtract initial from final frequency: $0.55-0.40=0.15$.

136. What is the genotype frequency of heterozygotes (Aa) if $24$ of $80$ individuals are Aa?

     $0.30$. Divide the number of Aa individuals by the total number of individuals.

137. What is phenotype frequency in a population, expressed as a proportion?

     Individuals with the trait divided by total individuals. Divide individuals showing the trait by total population size.

138. Identify the allele $a$ count if a population has $200$ total alleles and $q=0.65$.

     $a=q \times 200=0.65 \times 200=130$. Multiply total alleles by frequency to get count.

139. Which generation shows stronger selection for a trait: $12$ survivors or $30$ survivors?

     $30$ survivors (higher survival proportion). Higher survival proportion indicates stronger selection pressure.

140. Identify which population has higher trait frequency: $12/40$ or $30/120$.

     Neither; both are $0.30$. Both equal $0.30$ when calculated as decimals.

141. What is allele frequency in a population, written using proportional reasoning?

     Allele frequency = \frac{\text{# of that allele}}{\text{total # of alleles}}. Compares specific allele count to total allele count in gene pool.

142. Find and correct the error: "$70$ of $200$ individuals have the trait, so frequency is $0.35\%$." What is the correct frequency?

     $0.35$. Frequency is decimal, not percent: $\frac{70}{200} = 0.35$.

143. What is the genotype frequency of AA if $18$ of $60$ individuals are AA?

     $0.30$. Divide the number of AA individuals by the total number of individuals.

144. What is the definition of gene flow using proportional reasoning?

     Change in allele proportions caused by migration into or out of a population. Movement of individuals between populations changes allele proportions.

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

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

146. What is the percent of individuals with a trait if $15$ of $60$ individuals show it?

     $25\%$. Convert fraction to percent: $\frac{15}{60} = 0.25 = 25\%$.

147. What is the percent increase if allele A frequency changes from $0.20$ to $0.30$?

     $50\%$. Percent increase = $\frac{0.30-0.20}{0.20} \times 100\% = 50\%$.

148. Identify the correct proportion formula for allele A frequency: p=\frac{\text{# A alleles}}{\text{# total alleles}} or p=\frac{\text{# AA}}{\text{# individuals}}?

     p=\frac{\text{# A alleles}}{\text{# total alleles}}. Count all A alleles (not just AA individuals) divided by total alleles.

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

     $0.60$. Survival rate = survivors/total = $\frac{12}{20} = 0.60$.

150. What is phenotype frequency in a population, written using proportional reasoning?

     Phenotype frequency = \frac{\text{# with phenotype}}{\text{total population}}. Compares individuals with trait to total population size.

151. Calculate survivors: if $\frac{3}{5}$ survive out of $250$ individuals, how many survive?

     $150$. $\frac{3}{5} \times 250 = 150$ individuals survive.

152. What is the frequency of allele a if $p=0.65$ and $p+q=1$?

     $0.35$. Use $q = 1 - p$ since allele frequencies must sum to 1.

153. What is the percent change in allele frequency if $p$ goes from $0.20$ to $0.30$?

     $0.30-0.20 = 0.10$ (a 10 percentage-point increase). Subtract initial frequency from final frequency for change.

154. Which claim is best supported: trait count rose from $20$ to $30$, but total rose from $100$ to $200$?

     Trait frequency decreased (from $20\%$ to $15\%$). Proportion fell from $\frac{20}{100}$ to $\frac{30}{200}$

155. Which statement correctly links natural selection to proportional reasoning?

     Traits that increase survival/reproduction rise in frequency over generations. Advantageous traits increase proportionally through differential reproduction.

156. A trait proportion changes from $0.20$ to $0.30$. What is the absolute change in proportion?

     $0.10$. Subtract old proportion from new proportion.

157. Calculate allele A frequency $p$ if there are $30$ A alleles out of $100$ total alleles.

     $p=0.30$. Divide number of A alleles by total alleles: $\frac{30}{100}=0.30$.

158. Which population has the higher trait frequency: $12$ of $40$ or $18$ of $90$?

     $12$ of $40$ (since $0.30 > 0.20$). $\frac{12}{40} = 0.30$ while $\frac{18}{90} = 0.20$

159. Compute the survival rate if $45$ of $150$ offspring survive to reproduce.

     $45 150 = 0.30$ (30%). Divide survivors by total offspring for survival proportion.

160. What is the definition of genotype frequency using proportional reasoning?

     Genotype frequency = $$number with a genotype$ total individuals$. Counts individuals with specific genotype divided by total population.

161. Identify the percent allele frequency of $B$ if its proportion is $0.08$.

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

162. What is the genotype frequency of $Aa$ if $48$ of $160$ individuals are $Aa$?

     $0.30$. Divide number of Aa individuals by total: $\frac{48}{160} = 0.30$.

163. Identify the percent increase if an allele's proportion changes from $0.20$ to $0.30$.

     $\frac{0.30-0.20}{0.20}=0.50$ (50% increase). Use $\frac{new-old}{old}$ to calculate percent change.

164. Which option best supports evolution: trait proportion stays $50\%$ each generation, or changes from $20\%$ to $35\%$?

     Changes from $20\%$ to $35\%$. Evolution requires change in proportions over generations.

165. Choose the correct inference: allele $A$ rises from $0.10$ to $0.30$. Did $A$ become more common?

     Yes, the proportion of allele $A$ increased. Frequency tripled from 0.10 to 0.30, showing A became more common.

166. Identify the correct comparison using ratios: Population A has $8$ of $40$ resistant; B has $12$ of $100$ resistant.

     Population A (0.20) has a higher resistant proportion than B (0.12). A: $\frac{8}{40}=0.20$; B: $\frac{12}{100}=0.12$; A has higher proportion.

167. Which statement correctly connects natural selection to proportions in a population?

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

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

     $30\%$. Percent = $\frac{18}{60} \times 100$.

169. Find the allele frequency of $A$ if $AA=10$, $Aa=30$, $aa=10$ in a diploid population.

     $(210+30) (250)=50 100=0.50$. Count all $A$ alleles: $20$ from $AA$ plus $30$ from $Aa$, then divide by total.

170. Which population has a higher trait proportion: $12$ of $30$ or $20$ of $80$?

     $\frac{12}{30}$ is higher. $\frac{12}{30} = 0.40 > \frac{20}{80} = 0.25$

171. Compute survivors proportion: $40$ of $50$ insects survive pesticide. What proportion survived?

     $0.80$. $\frac{40}{50} = 0.80$ survived the treatment.

172. Identify the percent frequency if an allele proportion is $0.08$.

     $8\%$. Convert decimal to percent by multiplying by 100.

173. What is the relative fitness of genotype X if it leaves $12$ offspring and the best genotype leaves $16$?

     $0.75$. Relative fitness = offspring of X ÷ max offspring: $\frac{12}{16}$.

174. Identify the change in proportion if an allele goes from $0.25$ to $0.40$ in one generation.

     Increase of $0.15$. Subtract initial from final: $0.40 - 0.25 = 0.15$.

175. Calculate phenotype frequency if $18$ of $60$ individuals show the trait.

     $\frac{18}{60}=0.30$. Divide individuals with trait by total individuals.

176. Identify the correct interpretation if allele A frequency increases from $0.30$ to $0.45$ in $5$ generations.

     Allele A became more common (evolution occurred). Increasing allele frequency indicates evolutionary change.

177. What does it mean if an allele's proportion increases from one generation to the next?

     That allele is becoming more common in the population. Higher proportion means the allele spreads through the population.

178. Identify the allele frequency $p$ if $AA=16$, $Aa=8$, and $aa=1$ individuals are observed.

     $p=\frac{2(16)+8}{2(25)}=\frac{40}{50}=0.80$. Count all $A$ alleles (2 per $AA$, 1 per $Aa$) and divide by total.

179. Identify the selection coefficient $s$ if relative fitness is $w = 0.80$.

     $s = 0.20$. Selection coefficient $s = 1 - w = 1 - 0.80 = 0.20$.

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

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

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

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

182. Identify the correct comparison: Population X has $12$ of $30$ with a trait; Y has $18$ of $60$. Which has higher proportion?

     Population X. X: $\frac{12}{30} = 0.40$; Y: $\frac{18}{60} = 0.30$; X is higher.

183. Compute the percent of a population with genotype AA if $12$ out of $80$ individuals are AA.

     $\frac{12}{80}=0.15=15\%$. Convert to percent by multiplying decimal by 100.

184. If $60\%$ of a population is green and the population size is $150$, how many are green?

     $90$. Multiply population size by the percentage: $150 × 0.60 = 90$.

185. What is the frequency of allele A if $p=\frac{4}{5}$? Give a decimal.

     $0.80$. Convert the fraction $\frac{4}{5}$ to decimal form.

186. What is the definition of genetic drift using proportional reasoning?

     Random change in allele proportions, strongest in small populations. Chance events cause larger proportion shifts in smaller populations.

187. Which expression gives allele frequency $p$ from counts of alleles: A count $A$ and total alleles $T$?

     $p=\frac{A}{T}$. Allele frequency equals count of specific allele over total alleles.

188. Which idea explains why proportions are preferred over raw counts when populations differ in size?

     Proportions control for different sample sizes. Proportions allow fair comparison between different-sized groups.

189. Calculate survivors: if $70\%$ survive and there are $200$ individuals, how many survive?

     $140$. $0.70 \times 200 = 140$ individuals survive.

190. Find the percent with a trait if $45$ of $200$ individuals show it.

     $22.5\%$. Calculate $\frac{45}{200}\times 100\%=22.5\%$.

191. Which evidence best supports selection for a trait: same percent each generation or increasing percent each generation?

     Increasing percent each generation. Rising proportions show the trait is being selected for.

192. Identify the genotype frequency of $AA$ if $18$ of $60$ individuals are $AA$.

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

193. Which option best explains why proportions are preferred over raw counts in evolution data?

     Proportions control for different sample sizes across populations. Proportions allow fair comparison between different-sized populations.

194. What is the operational definition of evolutionary change used in middle school life science?

     A change in trait or allele proportions over generations. Proportions changing over time indicates evolution occurring.

195. Choose the correct conclusion: resistant insects rise from $10\%$ to $40\%$ after spraying. What occurred?

     Natural selection increased the resistant trait proportion. Pesticide killed non-resistant insects, shifting proportions.

196. Identify the percent increase if a trait rises from $20\%$ to $30\%$ in one generation.

     $10\%$ (a $10$ percentage-point increase). The difference in percentages: $30\% - 20\% = 10$ percentage points.

197. Convert $40\%$ of a population to a proportion.

     $0.40$. Divide 40 by 100 to convert percent to decimal.

198. Convert a trait frequency of $0.25$ to a percent.

     $25\%$. Multiply decimal frequency by 100 to get percent.

199. Which population shows stronger selection for a trait: frequency increases by $0.10$ or by $0.02$ in one generation?

     The population with the $0.10$ increase. Larger frequency change indicates stronger selective pressure.

200. Find the ratio of dark to light beetles if dark = $80$ and light = $20$.

     $4:1$. Simplify $\frac{80}{20}$ to lowest terms: $4:1$.

201. What is the definition of genetic drift in terms of proportions?

     Random changes in allele proportions, strongest in small populations. Chance events alter allele frequencies, especially in small groups.

202. What does it mean if a trait proportion stays constant across many generations?

     No measurable evolutionary change for that trait in that population. Stable proportions indicate no evolutionary forces are acting.

203. Which proportional measure best supports a claim of evolutionary change: counts or percentages?

     Percentages (proportions), because population size can vary. Proportions allow fair comparison across different population sizes.

204. Which option correctly interprets a population where allele $R$ changes from $0.40$ to $0.55$ in one generation?

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

205. Find allele frequency $p(A)$: a gene pool has $40$ $A$ alleles and $60$ $a$ alleles. What is $p(A)$?

     $0.40$. $\frac{40}{40+60} = \frac{40}{100} = 0.40$

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

     $50\%$. Relative increase = $\frac{15-10}{10} \times 100$.

207. What is a selective advantage in evolutionary terms?

     Higher survival and reproduction than other individuals. These individuals are more likely to pass on their traits.

208. What is the allele frequency of A if $40$ of $200$ total alleles are A?

     $0.20$. Divide the number of A alleles by the total number of alleles.

209. What is natural selection in one precise sentence?

     Individuals with advantageous traits leave more offspring. This differential reproduction drives evolutionary change.

210. Which statement best describes microevolution in proportional terms?

     A change in allele frequencies (proportions) across generations. Evolution occurs when allele proportions shift over time.

211. Choose the correct inference if a trait proportion increases each generation under predation.

     Natural selection is favoring that trait. Rising frequency under pressure indicates selective advantage.

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

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

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

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

214. What is the definition of natural selection in terms of proportions?

     A change in trait or allele proportions due to differential survival and reproduction. Traits that help survival/reproduction become more common over time.

215. Identify the term for a change in allele frequency in a population across generations.

     Evolution. Allele frequency changes define evolution at the genetic level.

216. Identify the correct claim: "Evolution occurs when individuals change" or "Evolution occurs when allele proportions change."

     Evolution occurs when allele proportions change. Populations evolve through changing allele frequencies, not individual changes.

217. Identify the term for a consistent change in allele frequency in a population across generations.

     Evolution. Evolution is defined as change in allele frequencies over time.

218. Find and correct the comparison error: "Population A has more of the trait because $30>20$." What should be compared?

     Compare proportions (for example, $\frac{30}{N_A}$ vs $\frac{20}{N_B}$). Raw counts mislead; must compare as proportions of each population.

219. Find the missing count: $25\%$ of $200$ fish have a trait. How many fish have the trait?

     $50$. $0.25 \times 200 = 50$ fish have the trait.

220. What is the definition of gene pool using population proportions?

     All alleles in a population, counted as totals used to find frequencies. Sum of all alleles forms denominator for frequency calculations.

221. What does it indicate if an advantageous trait's proportion increases from one generation to the next?

     That trait is being favored by selection (higher relative fitness). Increasing frequency shows the trait improves reproductive success.

222. What is allele frequency in a population, stated as a proportion?

     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.

223. What is the definition of fitness in evolution (proportional reasoning context)?

     Relative reproductive success, measured by contribution to the next generation. Higher fitness means more offspring, increasing that trait's proportion.

224. What is the genotype frequency of $AA$ if $25$ of $200$ individuals are $AA$?

     $0.125$. Divide number of AA individuals by total individuals.

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

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

226. What is the formula for change in allele frequency from generation $1$ to $2$?

     $\Delta p=p_2-p_1$. Subtracts initial frequency from final to measure change.

227. In $80$ diploid individuals, $30$ are $AA$, $40$ are $Aa$, and $10$ are $aa$; what is $p$ (A allele frequency)?

     $0.625$. $p = \frac{2(30)+40}{2(80)} = \frac{100}{160} = 0.625$.

228. What is the formula for percent of a trait in a population?

     $\text{percent} = \frac{\text{number with trait}}{\text{total}} \times 100$. Multiply by 100 to convert proportion to percentage.

229. Which process is best supported when a trait proportion rises after a new predator appears: natural selection or genetic drift?

     Natural selection. Predator pressure causes differential survival, driving selection.

230. Find the new trait frequency if it rises from $10\%$ to $25\%$ in one generation.

     $25\%$. The question asks for the new frequency, which is $25\%$.

231. Identify the correct conclusion if a trait's proportion increases after an environmental change.

     The trait likely provides a selective advantage. Increasing frequency suggests trait improves survival/reproduction.

232. Calculate the survival ratio if phenotype 1 has $24$ survivors and phenotype 2 has $12$ survivors.

     $2$ (a $2:1$ survival ratio). $\frac{24}{12} = 2$, meaning phenotype 1 survives twice as well.

233. What is the formula for allele frequency of $A$ if counts are $AA, Aa, aa$ in $N$ organisms?

     $p(A)=\frac{2(AA)+(Aa)}{2N}$. Count all $A$ alleles (2 per $AA$, 1 per $Aa$) divided by total alleles ($2N$).

234. What is relative fitness, stated as a ratio using survival or reproduction?

     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.

235. What is the ratio of dark to light beetles if there are $45$ dark and $15$ light?

     $3:1$. Simplify the ratio by dividing both numbers by their GCD (15).

236. What is the allele proportion if there are $40$ copies of allele $a$ out of $200$ total alleles?

     $0.20$. Calculate $\frac{40}{200} = 0.20$ for the proportion.

237. What is allele frequency in a population, expressed as a proportion?

     Allele count divided by total alleles for that gene. Divide specific allele copies by total alleles to get the proportion.

238. What is the definition of relative fitness using proportional reasoning?

     Reproductive success as a ratio compared with the highest-success type. Compares offspring production to the most successful type as a ratio.

239. What relationship must hold between allele frequencies $p$ and $q$ for two alleles?

     $p+q=1$. All alleles at a locus must sum to 100% of the gene pool.

240. In Gen 1, $50$ of $200$ are resistant; in Gen 2, $90$ of $300$ are resistant. Which generation has higher resistance frequency?

     Gen 2 (Gen 1 $=0.25$, Gen 2 $=0.30$). Gen 2 has higher frequency despite larger population.

241. What is the definition of mutation in terms of population proportions?

     A DNA change that can introduce new alleles and alter allele proportions. Creates new genetic variants that can shift population proportions.

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

     $80$. Diploid organisms have 2 alleles per gene, so $40 \times 2 = 80$.

243. Which term describes allele proportion changes caused by movement of individuals?

     Gene flow (migration). Immigration or emigration introduces or removes alleles from populations.

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