| A | B |
|---|
| The four nitrogenous bases in DNA | Adenine (A), guanine (G), cytosine (c), thmine (T) |
| Adenine and Guanine are both? | Purines |
| Thymine and Cytosine are both? | Pyrimidines |
| What is one difference in the appearance of purines, pyrimidines? | Purines are bigger |
| Formed by two strands of nucleotids twisted together | Double Helix |
| The process by which DNA is copied | replication |
| Are genes located on the same chromosome | Linked genes |
| Refers to the recombination of alleles that occurs when neighboring segments of tetrads break off when they meet and exchange genetic material | Crossing Over |
| determine weather the offspring are male or female | Sex chromosome |
| All non-sex chromosomes | autosomes |
| Together X linked genes and Y linked genes are ? | Sex-linked genes |
| Are expressed only in the presence of sex hormones and are only observed in one sex or the other | Sex-limited traits |
| Are expressed in both sexes, but they are expressed differently | Sex influenced traits |
| A photograph of all of an organisms chromosomes | karyotype |
| the base sequence of all of the DNA in an organism | genome |
| The failure of chromosomes to seperate during cell division | nondisjunction |
| The zygote has only one copyof a particular chromosome | Monosomy |
| The zygote has three copies of a chromosome | Trisomy |
| when nondisjunction occurs in all chromosome pairs | Polyploidy |
