Why is it important for DNA replication to be accurate?
In order for a cell to divide, it must first make a copy of its own DNA, which is the genetic code it needs to function properly. It is very important that your DNA is replicated accurately, with new cells receiving an exact copy of your genetic sequence.
What happens if DNA is altered?
When a gene mutation occurs, the nucleotides are in the wrong order which means the coded instructions are wrong and faulty proteins are made or control switches are changed. The body can’t function as it should. Mutations can be inherited from one or both parents. They are present in the egg and/ or sperm cells.
What triggers replication?
The initiation of DNA replication occurs in two steps. First, a so-called initiator protein unwinds a short stretch of the DNA double helix. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands.
What makes exact replication of DNA possible?
What makes exact DNA replication possible? The geometry of individual base pairs allows only one base to form a hydrogen bond with its complement base.
What actually happens to DNA before or as it is replicated copied?
Question 1 2 pts What actually happens to DNA before or as it is replicated/copied? It must unwind. It must unwind and be copied first Enzymes attach to the DNA and unwind the molecule and nucleotides pair up, A with T and G with C Enzymes attach to the DNA and cut it into pieces that can be replicated.
What are the four major stages of Karyokinesis?
Karyokinesis is the division of nuclear material. It occurs in four stages. They are prophase, metaphase, anaphase and telophase.
What would happen if DNA did not replicate before cell division?
Since the cell is dividing it needs two copies of its DNA – one is kept by the parent cell and the other is passed to the daughter cell. If cells don’t replicate their DNA or don’t do it completely, the daughter cell will end up with no DNA or only part of the DNA. This cell will likely die.
What happens if cell division does not occur?
After the cytoplasm divides, cell division is complete. If the cell cycle is not carefully controlled, it can cause a disease called cancer, which causes cell division to happen too fast. A tumor can result from this kind of growth.
Which phase of mitosis is the shortest?
anaphase
What are the stages of mitosis and what happens in each stage?
Mitosis is the process in which the nucleus of a eukaryotic cell divides. During this process, sister chromatids separate from each other and move to opposite poles of the cell. This happens in four phases, called prophase, metaphase, anaphase, and telophase.
What is the second stage of mitosis?
When prophase is complete, the cell enters prometaphase — the second stage of mitosis. During prometaphase, phosphorylation of nuclear lamins by M-CDK causes the nuclear membrane to break down into numerous small vesicles. As a result, the spindle microtubules now have direct access to the genetic material of the cell.
What does each duplicated chromosome have two of?
each DUPLICATED chromosome has two sister chromatids. The two chromatids each contin an identical DNA molecule and are attached by cohesins which is a protein complex. – also known as sister chromatid cohesion. Before duplication each chromosome has a single DNA molecule.
How long does each stage of mitosis take?
The time required then for the complete process of mitotic cell division would lie within the following limits: Prophase, 30 to 60 minutes; metaphase, 2 to 10 minutes; anaphase 2 to 3 minutes; telophase 3 to 12 minutes and the reconstruction period from 30 t’o 120 minutes: total 70 to 180 minutes.