DNA Replication
What enzyme unwinds the DNA double helix?
Helicase
What type of cell division produces 2 identical daughter cells?
Mitosis
What is the Law of Segregation?
Mendel’s law stating that the two alleles for a gene separate into different gametes.
What is the phase of the cell cycle where DNA is replicated?
S phase
Define an allele
Different versions of a gene
Okazaki Fragments
In what process is the chromosome number reduced from diploid to haploid?
Meiosis
What is the Law of Independent Assortment?
Mendel’s law stating genes for different traits separate independently.
What repair fixes mismatched bases after replication?
Mis match repair
In meiosis, are the daughter cells genetically different or identical?
Genetically different
What direction does the DNA polymerase move?
5' to 3'
What separates during anaphase of mitosis?
Sister chromatids
What specific phase does segregation occur?
the separation of homologous chromosomes in meiosis I
What repair fixes small, damaged bases and reseals the backbone?
base excision repair
Contrast what happens during metaphase l vs metaphase ll in meiosis
Metaphase I: Homologous chromosome pairs (tetrads) line up at the cell’s center.
Metaphase II: Sister chromatids line up at the center.
Contrast the direction of the leading vs lagging strand
Leading towards replication fork
Lagging away replication fork
What separates during Anaphase 1 of meiosis?
What specific phase does Independent assortment occur?
The random alignment of homologous pairs in metaphase I
What enzyme adds non coding regions of DNA to the ends of the DNA strand?
Telomerase
True or False
DNA polymerase can start building a new strand by itself.
False. It needs a primer
If the replication fork moves to the left, and the bottom template strand runs 3′ → 5′ (left to right), which strand is the lagging strand?
The bottom strand
The fork is moving left, but the bottom template runs 3′ → 5′ (left to right), so the new strand is made 5′ → 3′ away from the fork, making it lagging
Crossing over occurs in what phase of meiosis?
Prophase l
What is the difference between genotype and phenotype?
The genotype is the set of alleles an organism carries (its genetic code), while the phenotype is the observable trait or characteristic that results from those alleles.
What type of repair is active during DNA replication?
exonuclease proofreading by the DNA polymerase
In a cross between Tt × Tt, what percent of offspring are expected to be homozygous recessive?
25%