Section 1
Punnett Squares Predict Inherited Traits
Scientists use Punnett squares to show how parents' alleles combine in offspring. These diagrams display possible genotypes and help predict which traits offspring might inherit from their parents.
Grade 7 Life Science students learn how to use Punnett squares to predict patterns of heredity by mapping how alleles from each parent combine in potential offspring. The lesson also covers how to express genetic outcomes using ratios, percentages, and probability, illustrated through examples like Mendel's pea plant height crosses. This content is part of Chapter 4: Patterns of Heredity in the Grade 7 Life Science textbook.
Section 1
Punnett Squares Predict Inherited Traits
Scientists use Punnett squares to show how parents' alleles combine in offspring. These diagrams display possible genotypes and help predict which traits offspring might inherit from their parents.
Section 2
Ratios Calculate Genetic Probabilities
Probability shows the likelihood of specific genetic outcomes. We can express these chances as ratios (like 3:4) or percentages (like 75%). Both help predict how often certain traits might appear.
Section 3
Meiosis Creates Unique Reproductive Cells
Unlike mitosis, meiosis produces gametes (eggs and sperm) with half the normal chromosomes. This special cell division ensures offspring get genetic material from both parents without doubling chromosome numbers.
Section 4
Dominant Alleles Mask Recessive Traits
When offspring inherit both dominant and recessive alleles for a trait, the dominant trait appears in the phenotype. This explains why some traits show up more frequently than others.
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Section 1
Punnett Squares Predict Inherited Traits
Scientists use Punnett squares to show how parents' alleles combine in offspring. These diagrams display possible genotypes and help predict which traits offspring might inherit from their parents.
Section 2
Ratios Calculate Genetic Probabilities
Probability shows the likelihood of specific genetic outcomes. We can express these chances as ratios (like 3:4) or percentages (like 75%). Both help predict how often certain traits might appear.
Section 3
Meiosis Creates Unique Reproductive Cells
Unlike mitosis, meiosis produces gametes (eggs and sperm) with half the normal chromosomes. This special cell division ensures offspring get genetic material from both parents without doubling chromosome numbers.
Section 4
Dominant Alleles Mask Recessive Traits
When offspring inherit both dominant and recessive alleles for a trait, the dominant trait appears in the phenotype. This explains why some traits show up more frequently than others.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter