Mitosis Flashcards
(21 cards)
What are the four stages of the mitotic cell cycle?
G1, S phase, G2, M phase
G1: growth, S: DNA replication, G2: preparation for division, M: mitosis
What does interphase include?
G1, S, G2
Interphase is the phase where the cell grows and prepares for division.
What occurs during the G1 phase of the cell cycle?
The cell carries out normal metabolic processes and makes proteins and new organelles.
What is the S phase of the cell cycle responsible for?
DNA undergoes semi-conservative replication.
What role does DNA polymerase play during the S phase?
Checks for errors as new bases are added (proofreading).
What happens in the G2 phase of the cell cycle?
Further checks on DNA are made, mismatch repair occurs, and preparation for division is completed.
What is the structure of DNA within the nucleus?
DNA is found in the form of chromatin, made up of nucleosomes.
What are nucleosomes?
DNA wrapped around packaging proteins called histones.
What is semi-conservative replication?
The process where a double-stranded DNA molecule is split and each strand serves as a template for a new strand.
What is the role of topoisomerase in DNA replication?
It unwinds the double-stranded molecule.
What does helicase do during DNA replication?
Breaks hydrogen bonds between complementary base pairs.
What function do single-stranding binding proteins serve?
They keep the two strands of DNA apart during replication.
What is the purpose of RNA primase in DNA replication?
To add primers made from ribonucleotides.
What does DNA polymerase III do during DNA replication?
Proofreads the newly formed strand and catalyzes the synthesis of a new DNA strand.
What happens to primers after DNA synthesis?
Primers are removed, leaving gaps for DNA polymerase I to fill.
What is the role of DNA ligase in DNA replication?
Restores the sugar-phosphate backbone by forming phosphodiester bonds.
How can errors during DNA replication lead to SNPs?
Adenine may be incorrectly added instead of guanine, leading to a new DNA sequence.
What are SNPs?
Single nucleotide polymorphisms that occur due to replication errors.
What is the process of electrophoresis used for in forensic DNA typing?
To separate DNA samples based on size using an electric current through a gel.
What charge do DNA molecules carry?
Negatively charged due to phosphate groups.
True or False: Smaller lengths of DNA move faster than larger lengths during electrophoresis.
True.
