Chapter 2: Genetic and Environmental Foundations Midpoint Review

Genotype, phenotype and alleles What is the phenotype for this character’s eye color? What is the genotype? How do you know? What are some possible alleles for eye color? Is the character heterozygous or homozygous for eye color? What about hair color?

Can you place the labels: DNA, gene, chromosome?

Chromosomes What does this picture show? What do the numbers represent? What are autosomes? Where are they shown in the picture? What are sex chromosomes? Where are they shown in the picture?

Twins Explain how monozygotic twins differ from dizygotic twins. What are the more common terms we use for these two types of twins? Match each of the following terms with the appropriate description.   ______ This is the most common type of multiple birth. 1. Fraternal or ______ Older maternal age, use of fertility drugs and Dizygotic in vitro fertilization are major causes of this type of twins. ______ These twins are genetically no more alike 2. Identical or than non-twin siblings . Monozygotic ______ These twins share the same genetic makeup. ______ These twins result from one fertilized egg. ______ These twins result from two or more eggs fertilized by an equal number of sperm.

Mitosis, Meiosis and Abnormalities What is mitosis? What is meiosis? What is the most common chromosomal abnormality? How is it caused? Abnormalities of the sex chromosomes usually lead to (greater/fewer) problems than do those of the autosomes. Which diagram illustrates mitosis? Which shows meiosis?

Inheritance If a mother has brown hair and a father has blonde hair, what are the possible hair color outcomes (genotype and phenotype) for their children? What type of inheritance is demonstrated in this example? If a mother is heterozygous for Type A blood and the father is heterozygous for Type B, what are the possible blood type outcomes for their children? What type(s) of inheritance is demonstrated in this example?

Inheritance What type of inheritance is being illustrated in the diagram? Can you explain the possible outcomes between the F1 and F2 generations? Can you think of a human example where these same principles might apply?

Inheritance Why are males more like to inherit certain characteristics such as red-green colorblindness or Hemophilia? Can you illustrate this? How can a female offspring inherit these conditions? What is polygenic inheritance? What are some possible examples of human characteristics that might follow this pattern of inheritance?

X-linked Inheritance for Colorblindness

Preview Chapter 2 … still to come Chapter 3 Reproductive choices – Review and new Environmental contexts for development SES Heredity and behavior Advantages and Disadvantages of Parenthood Family size, birth order and timing Prenatal Development Prenatal Environmental Influences