DNA Structure
What are the three parts of a nucleotide?
phosphate, sugar, nitrogen base
A mutation occurs in a proto-oncogene - what result is most likely?
DNA replication occurs during...
S phase
Metaphase I, Meiosis I
The cell cycle typically produces _____ diploid cells with _____ DNA
2, identical
What makes up the backbone of DNA?
repeating phosphate, sugar pattern
Contact inhibition is important to prevent cancer cell growth because...
Begins at many locations - replication bubbles
Prophase I (Meiosis I) is different from mitosis because
crossing over occurs
Purpose of mitosis in multicellular organisms is for (2 things)
If a DNA molecule is 26% adenine, what percent is thymine?
A researcher finds mutations in sister chromatids. During which cell cycle phase did the mutation occur?
S phase
DNA polymerase synthesizes DNA from ___ to ___ on the new strand
5' to 3' on the new strand
Why do homologous chromosomes separate during Meiosis I?
To create haploid cells
A normal human egg and a n - 1 sperm results in _________
Monosomy
Long, loosely packed DNA is called
Chromatin
Nondisjunction occurs due to the cell cycle checkpoints because...
Checkpoints don't stop the cell cycle to make sure chromosomes separate (spindles attched)
Okazaki fragments are found on the ________ ______
lagging strand
If a cell has 4 chromosomes, there would be _____ DNA after telophase I and _____ DNA after telophase II.
4 DNA, 2 DNA
Nondisjunction results in daughter cells that are....
n+1 or n-1
Sister chromatids contain genes and DNA sequences that are...
identical
Cells that move away from the original tumor are...
Metastisizing
Helicase
Meiosis occurs to produce gametes because...
Animal = cleavage furrow, plant = cell plate because of cell wall