Download Bio102: Introduction to Cell Biology and Genetics

Bio102: Introduction to Cell Biology and Genetics
Mendel: Principles of Inheritance
Key Terms:
Gene
Allele
Haploid
Diploid
Genotype
Phenotype
Dominant
Recessive
Gamete
Homozygous
Heterozygous
True-breeding
Monohybrid Cross
Dihybrid Cross
Law of Segregation
Law of Independent Assortment
Key Questions:
 How are genes and alleles different?
 How do we know which allele is dominant for a particular character?
 How many alleles can one individual have for a particular gene? How many alleles can there be
in all the individuals of a population for that one particular gene?
 What were some of the things Mendel did differently that allowed him to reach a better
understanding of inheritance than all the scientists who had studied the problem before?
 In your own words (how would you explain it to your Mom?), what is Mendel's Law of
Segregation? What is Mendel's Law of Independent Assortment?
Lecture Outline:
All individuals of a species have the same genes
may have different alleles or forms of this gene
leads to a different protein (differences may be big or may be subtle)
each individual has two alleles of each genes (diploid) that may be same or different
allele combination (genotype) determines the result (phenotype)
each gamete (sperm or egg cell) gets only one allele of each pair
still has all the genes, just one copy of each (haploid)
offspring gets one allele from each parent
probability (chance) determines which allele the offspring gets
Mendelian Genetics
Genes are the physical unit of inheritance
Transferred from parent to child
All individuals have the same genes, but the genes can come in different forms (alleles)
Mendel’s Law of Segregation
Mendel’s Law of Independent Assortment