1. Meiosis and Sexual Life Cycles
1- Offspring acquire genes from parents by inheriting chromosomes
2- Fertilization and meiosis alternate in sexual life cycles
3- Meiosis reduces the number of chromosome sets from diploid to haploid
4- Genetic variation produced in sexual life cycles contributes to evolution

12. Law of segregation
Mendel’s first law, stating that each allele in a pair separates into a different gamete during gamete formation.
Law of independent assortment
Mendel’s second law, stating that each pair of alleles segregates independently during gamete formation; applies when genes for two characters are located on different pairs of homologous chromosomes.

16. Alleles: Alternative versions of genes

17. Complete dominance
The situation in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable.

20. Testcross
Breeding of an organism of unknown genotype with a homozygous recessive individual to determine the unknown genotype. The ratio of phenotypes in the offspring determines the unknown genotype.

23. Segregation of alleles and Fertilization as Chance events
Probability
Segregation of alleles and Fertilization as Chance events

24. Incomplete dominance
The situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele.

25. Multiple Alleles

26. Epistasis
A type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited.

27. Codominance
The situation in which the phenotypes of both alleles are exhibited in the heterozygote. Example: the human MN blood group is determined by codominant alleles for two specific molecules located on the surface of red blood cells, the M and N molecules.
Pleiotropy
The ability of a single gene to have multiple effects. Example: certain hereditary diseases in humans, such as cystic fibrosis and sickle–cell disease
Multifactorial
Referring to a phenotypic character that is influenced by multiple genes and environmental factors.
Polygenic inheritance
An additive effect of two or more gene loci on a single phenotypic character.