Animalscaretips
- Is DNA replicated during prophase?
- What is the replicated strand of DNA called?
- Is DNA replicated during prophase 1?
- How chromosomes are formed from strands of DNA during prophase?
- When during the cell cycle is cell's DNA replicated?
- What phase does DNA replicate mitosis?
- How do you replicate a strand of DNA?
- What happens during copying of DNA?
- What is the origin of each strand in the replicated DNA?
- Is the DNA replicated after meiosis 1?
- Does DNA replication occur in meiosis 1 or 2?
- What happens during prophase?
- What is a replicated chromosome?
- What distinguishes prophase I of meiosis from prophase of mitosis?
- What happens in prophase II?
Is DNA replicated during prophase?
A common misconception is that DNA copies itself during prophase, but this is not true. In prophase, the DNA has already been copied while the cell was in interphase. The chromosome number is the same in the daughter cells as it was in the parent cell.
What is the replicated strand of DNA called?
One strand is synthesized continuously in the direction of the replication fork; this is called the leading strand. The other strand is synthesized in a direction away from the replication fork, in short stretches of DNA known as Okazaki fragments. This strand is known as the lagging strand.
Is DNA replicated during prophase 1?
During prophase I, the chromosomes condense and become visible inside the nucleus. Because each chromosome was duplicated during the S phase that occurred just before prophase I, each now consists of two sister chromatids joined at the centromere. This arrangement means that each chromosome has the shape of an X.
How chromosomes are formed from strands of DNA during prophase?
During prophase, DNA condenses into tightly coiled chromosomes. Because DNA has already replicated, each chromosome appears as a joined pair of identical sister chromatids, forming the X shape that you can see in Figure B-9. Another important part of this stage is the formation of the mitotic spindle.
When during the cell cycle is cell's DNA replicated?
During interphase, the cell grows and DNA is replicated. During the mitotic phase, the replicated DNA and cytoplasmic contents are separated, and the cell divides.
What phase does DNA replicate mitosis?
In the eukaryotic cell cycle, chromosome duplication occurs during "S phase" (the phase of DNA synthesis) and chromosome segregation occurs during "M phase" (the mitosis phase).
How do you replicate a strand of DNA?
DNA replication occurs through the help of several enzymes. These enzymes "unzip" DNA molecules by breaking the hydrogen bonds that hold the two strands together. Each strand then serves as a template for a new complementary strand to be created. Complementary bases attach to one another (A-T and C-G).
What happens during copying of DNA?
How is DNA replicated? Replication occurs in three major steps: the opening of the double helix and separation of the DNA strands, the priming of the template strand, and the assembly of the new DNA segment. During separation, the two strands of the DNA double helix uncoil at a specific location called the origin.
What is the origin of each strand in the replicated DNA?
DNA replication initiates at specific points, called origins, where the DNA double helix is unwound. A short segment of RNA, called a primer, is then synthesized and acts as a starting point for new DNA synthesis. An enzyme called DNA polymerase next begins replicating the DNA by matching bases to the original strand.
Is the DNA replicated after meiosis 1?
Meiosis, divided into meiosis I and meiosis II, is a process in which a diploid cell divides itself into four haploid cells. Note that meiosis II immediately follows meiosis I; DNA replication does not occur after meiosis I.
Does DNA replication occur in meiosis 1 or 2?
Following this, meiosis II occurs. 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.
What happens during prophase?
Prophase. The first and longest phase of mitosis is prophase (Figure below). During prophase, chromatin condenses into chromosomes, and the nuclear envelope, or membrane, breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles (sides) of the cell.
What is a replicated chromosome?
A replicated chromosome (or equivalently, a duplicated chromosome) contains two identical chromatids, also called sister chromatids. The difference between a duplicated chromosome and a chromatid, strictly speaking, is that a chromosome contains two chromatids that are joined at a structure called a centromere.
What distinguishes prophase I of meiosis from prophase of mitosis?
In mitosis, prophase, metaphase, anaphase and telophase occur once. Chromosomes condense and the centrosomes begin to form an early spindle. Meiotic prophase I is much longer that mitotic prophase. During prophase I homologous chromosomes make contacts with each other called chiasmata and “crossing over” occurs.
What happens in prophase II?
During prophase II, the chromosomes condense, and a new set of spindle fibers forms. The chromosomes begin moving toward the equator of the cell. During metaphase II, the centromeres of the paired chromatids align along the equatorial plate in both cells.
