| A | B |
|---|
| The shape of DNA is described as a _____. | double helix |
| The monomers of DNA are ____. | nucleotides, 
|
| How many different types of nucleotides are found in a molecule of DNA?,
| four |
| What are the three parts to a nucleotide? | 1) nitrogenous base, 2) a sugar (In the case of DNA it is deoxyribose sugar. Thats where the D in DNA comes from. Deoxyribonucleic Acid), 3) phosphate group,  |
| DNA is a _____ stranded molecule. | double |
| Which nucleotide always bonds to thymine (T) across the middle where the nitrogenous bases meet?,
| adenine (A) |
| In DNA, which nucleotide always bonds to adenine (A) across the middle where the nitrogenous bases meet? | thymine (T) |
| Which nucleotide always bonds to cytosine (C) across the middle where the nitrogenous bases meet? | guanine (G) |
| Which nucleotide always bonds to guanine (G) across the middle where the nitrogenous bases meet? | cytosine (C) |
| During DNA replication, if the original strand of DNA has the base sequence CGGTATC, the new strand across from it will have the sequence of nucleotides ____. | GCCATAG |
| In which organelle is DNA located inside the cell? | In the nucleus (as part of a chromosome) |
| A chromosome is made of one long ______________ wrapped around histone _________. | molecule of DNA, proteins |
| DNA that is tightly coiled around histone proteins is known as a _____. | chromosome |
| How many chromosomes do most human cells hold? | 46, 23 pairs (as you can see for yourself in this karyotype),  |
| How many chromosomes do human sex cells have? | 23 total (1 of each type) |
| A segment of DNA that holds the code for a particular protein or trait is called a ____. | gene |
| The process of making a copy of a molecule of DNA is called ___. | DNA replication |
| Which enzyme adds nucleotides to the sides of the unzipped DNA molecule during DNA replication? | DNA polymerase |
| _______ results in 2 DNA molecules, each with one new strand and one original strand. | DNA replication |
| Which enzyme helps unzip DNA molecules during DNA replication? | Helicase |
| Which nucleotides are purines? | Adenine and Guanine (notice the double-ring structure in the nitrogenous base),  |
| Which nucleotides are pyrimidines? | Thymine and Cytosine (notice the single-ring structure in the nitrogenous base), |
| Thymine and cytosine have a _____ ring structure for their nitrogenous base and are classified as _____. | single, pyrimidines, |
| Adenine and guanine have a _____ ring structure for their nitrogenous base and are classified as _____. | double, purines, |
| When does DNA replication occur? | S phase of interphase before the start of mitosis or mieosis |
| Why does DNA replication need to occur? | So that the daughter cells of a dividing cell can each get a complete copy of DNA |
