Science
The Georgia Milestones science assessments are the grade 5 and grade 8 end-of-grade tests and the Biology end-of-course test. Grade 5 covers Earth and space science, physical science, and life science; grade 8 concentrates on matter, energy, force and motion, waves, and geology; Biology covers cells, genetics, evolution, ecology, classification, and homeostasis. Across all three, questions ask students to interpret data tables and graphs, evaluate experimental design, and explain models rather than merely recall vocabulary.
Core rules
- Identify the independent variable (changed by the investigator), the dependent variable (measured), the constants, and the control group before judging a conclusion.
- Conclusions may claim only what the data support; a correlation in a graph is not proof of causation.
- Energy flows through ecosystems and matter cycles; roughly 10 percent of energy passes to the next trophic level, the rest is lost mainly as heat.
- Prokaryotic cells lack a membrane-bound nucleus; eukaryotic cells have one.
- Mitosis produces genetically identical diploid cells for growth and repair; meiosis produces haploid gametes with genetic variation.
- Genotype is the allele combination; phenotype is the observable trait.
- Natural selection acts on existing variation in a population across generations.
- For forces, F = ma, and equal-and-opposite forces act on different objects.
- Wave speed equals frequency times wavelength.
Worked example
Two heterozygous parents (Bb × Bb) are crossed. What fraction of offspring is expected to show the recessive phenotype?
Each parent passes B with probability 1/2 and b with probability 1/2. The four equally likely combinations are BB, Bb, Bb, and bb, giving a 1:2:1 genotype ratio. Only bb shows the recessive phenotype, so the probability is 1/4, or 25 percent. Note that three-fourths show the dominant phenotype, but two of those three are heterozygotes - a distinction that matters in later crosses.
Traps that cost marks
- Explaining a trait by need (“the plant grew thorns because it needed protection”) instead of variation and selection.
- Confusing mitosis with meiosis.
- Confusing mass with weight.
- Saying energy is destroyed or used up rather than transferred and transformed.
- Confusing weather with climate.
- Changing two variables at once or omitting a control group.
- Drawing conclusions beyond the range of the data shown.