1. Relationship between Genotype and Phenotype
Molecular Basis for
Relationship between Genotype and Phenotype
genotype
DNA
DNA sequence
transcription
RNA
translation
amino acid
sequence
protein
function
phenotype
organism

2. Mutation: Levels of Hereditary Change
Gene (Point) Mutation:
One allele changes to a different allele.
Effects are limited to that locus.
Chromosome Mutation:
Changes occur at the chromosome level.
Multi-locus effects are not unusual.

3. Types of Chromosome Mutations
Refer to Figure 17-2, Griffiths et al., 2015.

4. Changes in Chromosome Number
I. Classes
A. Aberrant Euploidy
B. Aneuploidy
II. Euploidy
A. Monoploid (x): chromosome number in a basic set
B. Euploidy: multiples of monoploid number
C. Polyploid: euploid with > two sets of chromosomes
III. Examples of Polyploidy
A. Autopolyploidy : multiple chromosome sets from one species
B. Allopolyploidy: chromosome sets from different species

5. Refer to Table17-1, Griffiths et al., 2015.

6. Meiotic Pairing in Triploids
Refer to Figure 17-4, Griffiths et al., 2015.

7. Colchicine Induces Polyploidy
Refer to Figure 17-5, Griffiths et al., 2015.

8. Chromosome Pairing in an Autotetraploid
Refer to Figure 17-6, Griffiths et al., 2015.

9. Origin of the Amphidiploid Raphanobrassica
Refer to Figure 17-7, Griffiths et al., 2015.

10. Origin of Three Allopolyploid Species of Brassica
Refer to Figure 17-8, Griffiths et al., 2015.

11. Polyploidy in Animals
Parthenogenesis - development of unfertilized egg into embryo
polyploidy in leeches, flatworms, brine shrimp
polyploidy in salamanders, lizards
Polyploid frogs and toads undergo sexual reproduction.
Polyploid fish (such as salmon, trout) are not unusual.
Triploid oysters are of economic value.
In general, polyploid mammals are not viable.