Thus, when meiosis starts, there are two copies of each chromosome, attached as sister chromatids in the same chromosome. During prophase I, the chromosomes condense, as in mitosis. … Unlike in mitosis, the sister chromosomes stay together through meiosis I, but the homologous chromosomes are separated.
What are the differences between prophase and prophase I?
(i) It is a short phase and is not divided into any sub phase. (ii) Pair formation in between homologous chromosomes does not occur as there is no attraction between than. (iii) Chiasma is not formed. (iv) Crossing over does not occur.
What happens during prophase of mitosis?
Prophase is the first phase of mitosis, the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses.
What are the 2 main goals of meiosis?
The two broad goals of meiosis are to produce haploid daughter cells (gametes), and to generate variance.
What is the function of prophase 1?
Prophase I highlights the exchange of DNA between homologous chromosomes via a process called homologous recombination and the crossover at chiasma(ta) between non-sister chromatids. Thus, this stage is important to increase genetic variation.
Where does mitosis occur in our body?
Mitosis occurs in the cells for growth and for repair and replacement of the damaged and dead cells. Mitosis occurs actively in the bone marrow and skin cells to replace cells, which have a limited lifespan.
What happens during meiosis I?
However, Meiosis I begins with one diploid parent cell and ends with two haploid daughter cells, halving the number of chromosomes in each cell. Meiosis II starts with two haploid parent cells and ends with four haploid daughter cells, maintaining the number of chromosomes in each cell.