Human heredity examples

📚 Quick Study Guide

🧬 Genes: The basic units of heredity, made of DNA, that determine traits. 👨‍👩‍👧‍👦 Alleles: Different versions of a gene (e.g., allele for blue eyes vs. brown eyes). 📈 Genotype: The genetic makeup of an individual (e.g., BB, Bb, bb). 👁️ Phenotype: The observable characteristics of an individual (e.g., blue eyes, brown hair). 🧮 Dominant Allele: An allele that expresses its phenotype even when paired with a recessive allele. 🔬 Recessive Allele: An allele that only expresses its phenotype when paired with another recessive allele. 📜 Punnett Square: A diagram used to predict the genotypes and phenotypes of offspring.

Practice Quiz

1. What is the term for different versions of a gene?
1. Alleles
2. Genes
3. Chromosomes
4. Genotypes
2. If 'B' represents the dominant allele for brown eyes and 'b' represents the recessive allele for blue eyes, what is the phenotype of an individual with the genotype 'Bb'?
1. Blue eyes
2. Brown eyes
3. A mix of blue and brown eyes
4. Impossible to determine
3. What is the genetic makeup of an individual called?
1. Phenotype
2. Genotype
3. Karyotype
4. Allele
4. Which of the following is an example of a recessive trait that will only be expressed if both alleles are present?
1. Huntington's disease
2. Widow's peak
3. Attached earlobes
4. Freckles
5. What tool is used to predict the possible genotypes and phenotypes of offspring?
1. Mendelian chart
2. DNA sequencer
3. Punnett square
4. Pedigree analysis
6. A person with one copy of a dominant allele and one copy of a recessive allele for a trait will express:
1. The recessive trait
2. Neither trait
3. A blend of both traits
4. The dominant trait
7. If both parents are heterozygous (Bb) for a trait, what is the probability that their offspring will be homozygous recessive (bb)?
1. 25%
2. 50%
3. 75%
4. 100%