Can there be mitosis without DNA replication in S phase?

Without DNA replication in S phase, mitosis cannot occur. During DNA replication, DNA duplicates and this is a very important step. If DNA duplication does not occur than even in mitosis, there will be a reduction in the number of chromosomes of daughter cells. Thus, mitosis cannot occur without DNA replication.

Can there be mitosis without DNA replicate in S phase?

Mitotic cell division cannot take place without DNA replication in S phase. … DNA duplication is important as it maintains the chromosome number in the daughter cells. Mitosis is an equational division. Therefore, the duplication of DNA is an important step.

What happens if DNA does not replicate in S phase?

If a cell has not properly copied its chromosomes or there is damage to the DNA, the CDK will not activate the S phase cyclin and the cell will not progress to the G2 phase. The cell will remain in S phase until the chromosomes are properly copied, or the cell will undergo programmed cell death.

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Does DNA replication only occur in S phase?

The two G phases are essential for cell growth and protein synthesis, while the S phase is responsible for DNA replication. After meiosis I, DNA replication does not need to occur after meiosis I, as replication has already occurred before meiosis I.

Can cell division without DNA replication?

If a somatic cell, or body cell, divided without replicating its DNA or with incompletely replicating its DNA, the resulting daughter cells would be left with incomplete genetic material. … If the cell did not replicate its DNA at all, each daughter cell would be left with only half of a complete genome after division.

Why is mitosis called equational division?

Explanation: Mitosis is called equational division because each of the two daughter cells formed, get the same number of chromosomes as the parent.

Which stage of cell cycle do the following events occur in cell A Synapsis B chromosomes at Equatorial plate D centromere divide and chromatids separate?

In meiosis-i, the pairing between homologous chromosomes occurs in the zygotene stage of prophase-i. The zygotene is followed by the pachytene stage, where crossing over between homologous chromosomes takes place.

Why is DNA synthesis in S phase necessary?

S phase, or synthesis, is the phase of the cell cycle when DNA packaged into chromosomes is replicated. This event is an essential aspect of the cell cycle because replication allows for each cell created by cell division to have the same genetic make-up.

What is S phase in DNA replication?

S phase is the period of wholesale DNA synthesis during which the cell replicates its genetic content; a normal diploid somatic cell with a 2N complement of DNA at the beginning of S phase acquires a 4N complement of DNA at its end.

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Why is it important that the chromosomes be duplicated in the S phase?

Then, at a critical point during interphase (called the S phase), the cell duplicates its chromosomes and ensures its systems are ready for cell division. If all conditions are ideal, the cell is now ready to move into the first phase of mitosis.

Does transcription and translation occur in S phase?

Explanation: DNA replication occurs in the S-phase in interphase when the cell gets signal to start preparing for division. … DNA transcription and DNA translation are part of protein synthesis.

Does transcription occur in S phase?

However, in mammalian cells, the transcriptional events during S-phase are fast paced, as they all can occur during the course of 5–10 hours. … One of the most intriguing aspects of S-phase is how the timing of DNA replication and gene transcription events is coordinated.

Which of these must occur during S phase?

S phase. In S phase, the cell synthesizes a complete copy of the DNA in its nucleus. It also duplicates a microtubule-organizing structure called the centrosome. The centrosomes help separate DNA during M phase.

Can there be mitosis without cell division?

Yes, the DNA can replicate without cell division. When DNA replication is not followed by cell division the DNA keeps accumulating in the cell. For example – Polytene chromosomes found in drosophila is a result of DNA replication without cell division.

What would happen if DNA replication stopped?

The DNA replication occurs at the synthesis phase of the cell cycle. The cell cycle is regulated at each stage. If DNA replication does not occur, then the cell cycle will not proceed to the next stage and the subsequent division will not happen. It will lead to cell death.

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Why does DNA replication occur before mitosis?

DNA replication needs to occur because existing cells divide to produce new cells. Each cell needs a full instruction manual to operate properly. So the DNA needs to be copied before cell division so that each new cell receives a full set of instructions!