Studied by 0 people
Looks like no one added any tags here yet for you.
What is DNA replication?
The process of copying a DNA molecule to produce two identical DNA molecules.
When does DNA replication occur?
During the S phase of the cell cycle.
What enzyme unwinds the DNA double helix?
Helicase.
What are the building blocks of DNA?
Nucleotides.
Name the four nitrogenous bases in DNA.
Adenine (A), Thymine (T), Cytosine (C), Guanine (G).
What is the role of DNA polymerase?
To add nucleotides to the growing DNA strand during replication.
What is the leading strand in DNA replication?
The continuously synthesized strand of DNA that is synthesized in the same direction as the replication fork.
What is the lagging strand in DNA replication?
The strand that is synthesized in short segments, known as Okazaki fragments.
What are Okazaki fragments?
Short sequences of DNA nucleotides synthesized on the lagging strand during DNA replication.
What is semiconservative replication?
A method of DNA replication where each new DNA molecule contains one original and one new strand.
What is the function of primase?
To synthesize a short RNA primer for DNA polymerase to begin replication.
What is a replication fork?
The Y-shaped region where the two strands of DNA are separated to allow replication.
What is the origin of replication?
The specific location on the DNA molecule where replication begins.
How are errors in DNA replication corrected?
Through the action of proofreading by DNA polymerase and mismatch repair enzymes.
What is the role of ligase in DNA replication?
To join Okazaki fragments together on the lagging strand.
Define cell division.
The process by which a parent cell divides into two or more daughter cells.
What are the two main types of cell division?
Mitosis and meiosis.
What is mitosis?
The process of cell division that results in two genetically identical daughter cells.
What is meiosis?
The type of cell division that reduces the chromosome number by half, creating four genetically diverse gametes.
What are the phases of mitosis?
Prophase, Metaphase, Anaphase, and Telophase.
What occurs during prophase?
Chromatin condenses into visible chromosomes, and the nuclear envelope breaks down.
What occurs during metaphase?
Chromosomes line up along the metaphase plate in the center of the cell.
What occurs during anaphase?
Sister chromatids are pulled apart to opposite ends of the cell.
What occurs during telophase?
Chromatids reach the poles, and new nuclear membranes form around each set of chromosomes.
What is cytokinesis?
The division of the cytoplasm and organelles into two daughter cells following mitosis.
How does cytokinesis differ in plant and animal cells?
In animals, a cleavage furrow forms; in plants, a cell plate is formed.
What is the role of cyclins in cell division?
Cyclins regulate the cell cycle by activating cyclin-dependent kinases (CDKs).
What are checkpoints in the cell cycle?
Regulatory mechanisms that ensure the fidelity of cell division.
What is the G1 phase?
The first gap phase, where the cell grows and prepares for DNA replication.
What is the S phase?
The synthesis phase, where DNA is replicated.
What is the G2 phase?
The second gap phase, where the cell prepares for mitosis.
What is the role of p53?
A tumor suppressor protein that regulates the cell cycle and prevents tumor formation.
Define apoptosis.
The process of programmed cell death.
What is the difference between benign and malignant tumors?
Benign tumors are non-cancerous and do not invade other tissues, while malignant tumors are cancerous and can spread.
What is a centrosome?
The microtubule-organizing center that plays a role in mitosis.
What is chromosome segregation?
The process by which chromosomes are distributed into daughter cells during cell division.
What is a gene?
A segment of DNA that contains the instructions for making a protein.
What is replication stress?
A condition that impairs the DNA replication process, potentially leading to genomic instability.
What is telomere shortening?
The progressive loss of repetitive nucleotide sequences at the end of chromosomes with each cell division.
What is the role of telomerase?
An enzyme that extends the telomeres of chromosomes, maintaining their length during cell division.
What is DNA helicase?
The enzyme that unwinds the DNA double helix during replication.
Define sister chromatids.
Identical copies of a chromosome, connected by a centromere.
What is mitotic spindle?
A structure composed of microtubules that segregates chromosomes during mitosis.
What is a chromatid?
Each of the two identical halves of a duplicated chromosome.
Define haploid.
A cell that contains one complete set of chromosomes.
Define diploid.
A cell that contains two complete sets of chromosomes.
What is crossing over?
The exchange of genetic material between homologous chromosomes during meiosis.
What is independent assortment?
The process by which different genes independently separate from one another when reproductive cells develop.
