The purpose of this unit is to learn how Mendel’s identification of the factors that control heredity paved the way for an understanding of genetics at the cellular level. Students will learn about the chromosome theory and how gene linkage, crossing-over, and sex linkage contribute to the inherited characteristics of an organism. Students will also learn about gene mutations at two levels-the level of chromosomes and the level of genes. Finally, students will learn how the expression and activity of genes are regulated and controlled.
chromosome theory of heredity linked gene linkage group recombinant sex chromosome autosome X chromosome Y chromosome sex-linked mutation chromosomal mutation nondisjunction polyploidy gene mutation point mutation frameshift mutation incomplete dominance codominance polygenic operon operator promoter inducer repressor exon intron
State the chromosome theory of heredity
Explain how gene linkage affects inherited traits
Describe the process of crossing-over and explain how it increases genetic variety
Describe gene mapping
Describe the process of sex determination and the patterns of inheritance for sex-linked traits
Define the word mutation
Distinguish between germ and somatic mutations
Compare chromosomal and gene mutations
Describe the various types of chromosomal mutations
Describe the various types of gene mutations
Discuss the various factors that influence gene expression
Define and discuss dominance, incomplete dominance, and codominance
Compare the regulation of gene expression in prokaryotes and eukaryotes
Identify the components of an operon and explain how an operon is controlled
Discuss the roles of exons and introns in the transcription and processing of mRNA
The cell The molecular basis of heredity
10-1 The Chromosome Theory of Heredity
1. How are genes related to chromosomes? 2. How does crossing-over make genetic mapping possible? 3. What are sex chromosomes? Autosomes? 4. Why are the effects of recessive sex-linked alleles seen more often in males than in females?
1. Compare a chromosomal mutation and a gene mutation. 2. What is a somatic mutation? How does it differ from a germ mutation? 3. How does nondisjunction result in chromosomal mutations?
10-3 Regulation of Gene Expression
1. How do gene interactions affect gene expression? 2. Compare incomplete dominance and codominance. 3. What is a polygenic trait? 4. "Mutations in introns are less likely to affect phenotype than mutations in exons." Defend or refute this statement.