By Laura Tallarico
20 questions
8th - 8th Grade
Science
90 plays
Updated Apr 2026
This Grade 8 science worksheet helps students build foundational Punnett square skills through 20 questions: 16 multiple-choice items, one multiple-select item, and three fill-in-the-blank items. Students identify genotype, phenotype, alleles, homozygous and heterozygous combinations, and dominant and recessive representations. They also interpret allele pairs such as BB, Bb, and bb and determine which genotype or allele pattern an item describes. The worksheet then applies this vocabulary to inheritance probability, including calculating the expected percentage of offspring with a recessive trait and identifying missing or required genotypes in Punnett square setups. It is a free printable worksheet with a complete answer key for Grade 8 science instruction, independent practice, review, or formative assessment. The varied question formats give teachers multiple ways to check whether students can recognize genetic notation and use it to reason about possible offspring traits.
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WorksheetsAnswer KeyGenotype
Heterozygous
Phenotype
Homozygous
Dominant
Recessive
25%
BB
, b)bb
Rr
A tool scientist use to determine possible genotypes for offspring
dd
Gg
This Grade 8 science worksheet reinforces how to distinguish genotype, phenotype, allele, homozygous, heterozygous, dominant, and recessive concepts. Its multiple-choice, multiple-select, and fill-in-the-blank questions then ask students to interpret allele pairs such as BB, Bb, and bb and use Punnett square information to calculate inheritance probabilities, including a 50% or 25% chance for a specified recessive trait.
Introduce the vocabulary first by modeling how uppercase and lowercase letters represent dominant and recessive alleles, then contrast genotype combinations such as BB, Bb, and bb with observable phenotypes. Have students complete the identification questions before solving the probability items, and ask them to explain how the parent genotypes lead to each percentage choice in the Punnett square questions.
Watch for students confusing a genotype, such as Bb, with a phenotype, such as brown fur, or labeling a heterozygous pair as homozygous because it contains a dominant allele. Students may also overlook that a capital letter indicates a dominant allele, misclassify tt or Tt, count the wrong Punnett square outcomes when finding a percentage, or select only one response on the multiple-select item asking for two missing genotypes.
The worksheet is available as a printable PDF and as a digital quiz on Wayground, so you can assign the format that fits your Grade 8 science lesson. It includes a complete answer key for the genotype, allele, and inheritance-probability questions. For printable submissions, you can scan student work with the Wayground for Teachers app to help grade responses efficiently.
In the worksheet’s Advanced Settings, adjust font spacing or choose a larger font size to make the allele notation, answer choices, and Punnett square items easier to read. You can also apply a dyslexia-friendly font or translate the worksheet into another language while preserving its multiple-choice, multiple-select, and fill-in-the-blank format.
Wayground offers a broad collection of free printable worksheets and practice problems across subjects, with downloadable PDFs and answer keys to support mastery of essential skills and concepts. Browse more resources at https://wayground.com/en-us/worksheets.
