1. 1. Genetics-
2. Fertilization- process in sexual reproduction in which male & female reproductive
cells join to form a new cell
3. True breeding- term that is used to describe organisms that produce offspring
identical to themselves if allowed to self- pollinate
4. Trait- specific characteristics that varies from one individual to another
5. Hybrid-offspring of crosses between parents with different traits
6. Gene- sequence of DNA that codes for protein and thus determines a trait
7. Allele- one of a number of different forms of a gene
8. Segregation- separation of alleles during gamete formation
9. Gamete- specialized cell involved in sexual reproduction
10. Probability- likelihood that an event will happen
11. Punnett square-diagram shows the gene combinations that might result from a
genetic cross
12. Homozygous-term used to refer to an organism that has two identical alleles for a
particular trait
13. Heterozygous- term used to refer to an organism that has two differentalleles for
the same trait
14. Phenotype- physical characteristic of an organism
15. Genotype- genetic makeup of an organism
16. Independent assortment- independent segregation of genes during the formation
of gametes
17. Incomplete dominance- situation in which one allele is not completely dominant
over another
18. Codominance- situation in which both alleles of a gene contribute to the
phenotype of the organism
19. Multiple alleles- three or more alleles of the same gene
20. Polygenetic traits- trait controlled by two or more genes
21. Karyotype- set of photographs of chromosomes grouped in order in pairs
22. Sex chromosome- one of the two chromosomes an individual’s sex; females
have two X chromosomes; males have one X chromosome and one Y
chromosome
23. Pedigree- chart that shows the relationship within a family
24. Sex linked gene- gene located on the X or Y chromosome
25. Nondisjunction- error in meiosis in which homologous chromosomes fail to
separate
26. DNA fingerprinting- analysis of sections of DNA that have little or no functionbut
vary widely from one individual to another; in order to identify individuals
27. Genetic engineering- process of making changes in the DNA code of living
organisms
28. Restriction enzyme- enzyme that cuts DNA at a specific sequence of nucleotides
29. Recombatinant DNA- DNA produced by combining DNA from different sources
30. Plasma- straw colored fluid that makes up about 55 percent of blood; consist of
about 90 percent water and about 10 percent dissolved gases, salts, nutrients,
enzymes, hormones, waste products, and plasma proteins

2. 31. Clone- member of a population of genetically identical organisms produced from
a single cell