Dominant and Recessive Traits
Grade 7 · Science · Genetics and Heredity · Mississippi, USA
Lesson Summary
Find out why some traits show up more often than others in families.
Explanation
For many traits, you have two copies of each gene—one from each parent. A dominant allele only needs one copy to show its trait, while a recessive allele needs two copies (one from each parent) to appear. If you have one dominant and one recessive allele, the dominant trait is what you see. For example, if brown eyes (B) are dominant over blue eyes (b), a person with Bb will have brown eyes, but they still carry the blue-eye allele and could pass it to their children.
Practice Questions
Q1: A person has the genotype Bb for eye color, where B is brown (dominant) and b is blue (recessive). What eye color will they have?
Answer: They will have brown eyes because the dominant allele (B) masks the recessive allele (b).
Q2: Can two brown-eyed parents have a blue-eyed child? Explain.
Answer: Yes, if both parents carry one recessive allele (both are Bb). There is a 25% chance their child could be bb and have blue eyes.
Q3: What is the difference between genotype and phenotype?
Answer: Genotype is the combination of alleles an organism has (like Bb), while phenotype is the trait you can observe (like brown eyes).
People Also Ask
What is Dominant and Recessive Traits in Grade 7 Science?+
Dominant and Recessive Traits is a lesson in the Genetics and Heredity chapter of Grade 7 Science. It is part of the Mississippi, USA school curriculum and covers key concepts that students need to understand at this level.
What grade level covers Dominant and Recessive Traits?+
Dominant and Recessive Traits is taught in Grade 7 as part of the Science curriculum in Mississippi, USA.
How can I help my child with Genetics and Heredity in Science?+
Start with the lesson summary and explanation on this page. Practice the questions provided, then use TutorTom for personalized, step-by-step help with Genetics and Heredity topics.