Name _________________________________________
Unit #4 Genetics Study Guide – Chapter 11 Sections 1, 2 & 3
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Be able to interpret both types of Punnett squares.
Study all vocabulary terms in each Section (1-3) of Chapter 11
1. What is a hybrid? The offspring of parents with different homozygous genotypes.
2. What is a gene? The chemical factors that determine traits.
3. What did Gregor Mendel conclude about how traits are inherited? All traits are inherited through the passing of
factors from parents to offspring.
4. What does the principle of dominance state? States that some alleles are dominant and others are
recessive.
5. What is the difference between dominant and recessive genes? Dominant genes will be expressed over the
recessive genes in an organism; recessive genes are only expressed if both alleles are recessive.
6. Explain independent assortment of alleles. The principle of independent assortment states that genes for
different traits can segregate independently during the formation of gametes.
7. What is probability? The likelihood of an occurrence.
8. What are the principles of probability used for? Used to predict the traits of the offspring produced by genetic
crosses.
9. What is the difference between homozygous and heterozygous? Homozygous organisms have two identical
alleles for a particular trait. Heterozygous organisms have two different alleles for a particular trait.
10. What does a Punnett square show, what is it used for? Punnett squares can be used to predict and compare the
genetic variations that will result from a cross.
11. What are gametes? The sex cells in an organism.
12. What is incomplete dominance? Situation in which one allele is not completely dominant over another.
13. What is codominance? Situation in which both alleles of gene contribute to the phenotype of the organism.
14. What is a genotype? Genetic makeup of an organism.
15. What is a phenotype? Physical characteristics of an organism.