Unit 1 Scientific Approaches
Chapter 4
Genes and heredity
Basic Genetics
• 1.Genes are in pairs (alleles), one from each parent
• 2.dominant or recessive, homozygous or hetero
• 3.Genes segregate (separate) during reproduction
• 4.Genes assort independently, combos are random
• Genotype- genetic makeup, genes
• Phenotype- what it physically looks like
• Polygenetic traits- come from combo of many genes
• Ex: nose shape, hair color
DNA
• Genes located on chromosomes
• Some are sex linked (carried on X)
• Central Dogma• DNA --> RNA -->
Protein
• Haploid + Haploid= Diploid
• N + N = 2N• 23 from mom + 23
from dad = 46 baby
What Genes Do
Control body processes
Are not expressed all the time
Heritability:
Behavior= Genetics + Environment
Genetic Mutation and Evolution
• 1. Mutations- random change in genes, lead to new phys or beh traits
• 2. Gene flow- mov’t of indiv in or out of pop which changes allele frequency
• 3. Genetic drift- changes in gene pool by chance (environment changes, disease, etc)
• 4. Nonrandom mating- sex selection
Genes and Behavior
• Different genes lead to
• Different proteins and amino acids which lead to
• Different behavioral traits
Selection
• Artificial selection- selective breeding for certain traits
• Making hybrids to combine breed traits
• Instinctive drift- behavior gravitates toward strong instinctive pattern even when learning or training contradicts it
Top Related