What happens to the chromosomes during prophase?
During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses. The chromatin coils and becomes increasingly compact, resulting in the formation of visible chromosomes. … The sister chromatids are pairs of identical copies of DNA joined at a point called the centromere.
What happens to the chromosomes during metaphase quizlet?
The middle where the chromosomes line up. What happens to chromosomes during metaphase? They are attached to the spindle fiber and move to the center of the cell to line up. … They chromatids are pulled apart to opposite poles of the cell.
What happens to chromosomes during telophase quizlet?
What happens during Telophase? A nucleolus forms in each side. A new nuclear membrane forms around each new set of chromosomes, each with the same number of chromosomes as the original cell.
What happens prophase quizlet?
What happens during prophase? A cells genetic DNA condenses, spindle fibers begin to form and the nuclear envelope dissolves. … The duplicated chromosomes line up and spindle fibers connect to the centromeres. You just studied 9 terms!
What happens during prophase I?
During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis. The paired chromosomes are called bivalents, and the formation of chiasmata caused by genetic recombination becomes apparent. Chromosomal condensation allows these to be viewed in the microscope.
How is prophase I different from prophase II in meiosis quizlet?
In meiosis, how does prophase I differ from prophase II? During prophase I there is one diploid cell; during prophase II there are two haploid cells.
Which of the following occurs during prophase?
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. As the centrioles move, a spindle starts to form between them.
What happens in prophase simple?
prophase. [ prō′fāz′ ] n. The first stage of mitosis, during which the chromosomes condense and become visible, the nuclear membrane breaks down, and the spindle apparatus forms at opposite poles of the cell.
What happens in prophase I and not in prophase II?
Prophase II ends where metaphase II begins. The difference between prophase I and prophase II is that crossing over between chromosomes takes place only in prophase I, not on prophase II. See also: prophase I.
What happens by the end of prophase?
mitosis. Mitosis begins at prophase with the thickening and coiling of the chromosomes. The nucleolus, a rounded structure, shrinks and disappears. The end of prophase is marked by the beginning of the organization of a group of fibres to form a spindle and the disintegration of the nuclear membrane.
Does pairing of chromosomes occur during prophase?
At the end of prophase I, the pairs are held together only at the chiasmata (Figure 2) and are called tetrads because the four sister chromatids of each pair of homologous chromosomes are now visible. Figure 2. Crossover occurs between non-sister chromatids of homologous chromosomes.