Basic Genetics
Animal Breeding
Pensacola Jr College
Basis of Genetics
w DNA (deoxyribonucleic acid):
• Molecules made of
phosphates, sugars, and nitrogen bases which hold all the genetic information
in the nucleus of the cell
w Chromosomes:
• Condensed DNA holding
information on many traits
• Species-specific number
Basis of Genetics (cont’d)
w Nitrogen bases in the DNA of
the chromosomes varies, they are what does the coding of genetics
w When cells divide by
mitosis, resulting cells have same genetics
w Division by meiosis makes
variation in sperm/egg cells
DNA structure
3-D DNA
Review of
Mitosis and Meiosis
Genetics -
terminology
w Gene = a part of a
chromosome that codes for a trait in an organism
w Allele = forms of a gene
that code for variations of a trait
w Dominant allele = masks the
recessive allele, if present
w Recessive allele = only expressed
if dominant absent
Genetics -
terminology
w Homozygous = two identical
alleles on sister chroms
w Heterozygous = two different
alleles on sister chroms
w Genotype = what alleles are
present
w Phenotype = what trait
variation is expressed
Breeding Genetics
w Take information about male
parent to determine possibilities in sperm
w Take information about
female parent to determine possibilities in egg
w Determine possible genotypes
of offspring
w Figure out phenotypes
(traits)
Simple Genetics
Problems using
Punnett’s Squares:
Monohybrid and Dihybrid crosses