Mendelian inheritance is the focus of this Grade 8 Science worksheet for the NGSS topic Heredity: Inheritance and Variation of Traits. Students examine dominant and recessive alleles, segregation, Punnett squares, genotypes, phenotypes, and simple pedigrees while also considering why some human traits do not follow simple Mendelian patterns.

From Alleles to Predicted Traits

The reading passage introduces Gregor Mendel's pea plant studies and explains how paired alleles separate during reproduction. Students connect segregation with the inheritance of alleles and use simple dominant-recessive models to interpret genotype and phenotype patterns. The resource also introduces heterozygous crosses, including the expected 1:2:1 genotype pattern and commonly expected 3:1 phenotype pattern for complete dominance.

Inheritance Skills in Practice

• Explain how dominant and recessive alleles contribute to phenotypes.
• Use Punnett squares to predict possible genotype and phenotype patterns.
• Distinguish between genotypes containing two matching or different alleles.
• Describe allele segregation during reproduction.
• Interpret simple pedigrees showing traits across family generations.
• Recognize that polygenic inheritance and environmental effects can complicate simple models.

This Mendelian genetics practice worksheet includes a reading passage, multiple-choice questions, true-or-false statements, short-answer explanations, a labeled diagram, a categorization activity, and a short note. Students apply inheritance vocabulary and reasoning to questions about heterozygous parents, dominant and recessive alleles, Punnett squares, phenotypes, pedigrees, and limitations of simple inheritance models.

Support for Instruction and Review

The worksheet includes Student Notes lines at the bottom for recording key ideas. The Answer Key PDF includes a Teacher Guide with Learning Objectives, Teaching Tips, Discussion Questions, and Common Mistakes, providing practical support for teaching and reviewing heredity concepts.

Classroom Use

Use this genetics worksheet for guided practice after introducing Mendelian inheritance, independent classwork, review, or formative assessment. Students move from the basic idea of allele segregation to interpreting inheritance patterns and considering why dominant-recessive models cannot explain every human trait. This makes the resource useful for connecting foundational genetics vocabulary with simple inheritance predictions and biological variation.