q.1what is the role of chromosomes in inheritance?
q2 what is genetic recombination?
q3 what is genetic mapping?
q4 what is diffrance between mitosis and meiosis?
q5 what is cell cycle and what's the function of cell cycle? please answer me as soon as it 's possible
Hi Ritika,
1. Chromosomes play a very important role in inheritance, they contain the genetic material, DNA and it is the DNA that carries all the genetic information that is transferred from one generation to another.
2. Genetic recombination is the formation of new combinations of alleles in offspring as a result of exchange of DNA sequences between molecules. It occurs naturally, as in sexual reproduction during meiosis or artificially, as a result of experiments on genetic engineering.
3. Genetic mapping refers to the determination of the relative positions of genes on a DNA molecule.
4.
Mitosis | Meiosis | ||
(i) | It involves single division, resulting in the formation of two daughter cells. | (i) | It involves two successive divisions, namely meiosis I and II, resulting in the formation of four daughter cells. |
(ii) | It is also known as equational division as the daughter cell has the same number of chromosomes as the parent cell. | (ii) | Meiosis I is known as reductional division where the chromosome number is reduced to half. Meiosis II is known as equational division where the sister chromatids separate while the chromosome number remains the same. |
(iii) | The prophase stage is short and does not comprise of synapsis, crossing over, and the formation of chiasmata. | (iii) | Prophase I stage is very long. It comprises of five stages. In the zygotene stage of meiosis I, the pairing of homologous chromosomes takes place. During the pachytene stage, crossing over occurs while in the diplotene stage, chiasmata formation occurs. |
(iv) | It plays a significant role in cell growth, repair, and healing of wounds. | (iv) | It brings about variation and maintains constant chromosome number from one generation to another. |
(v) | It mainly takes place in the somatic cells. | (v) | It mainly takes place in the reproductive cells. |
5. Cell cycle refers to the sequence of events by which a cell duplicates its genome, synthesises other cell constituents, and eventually divides into two daughter cells. The events of the cell cycle are under genetic control. Phases of the cell cycle are:
Hope this helps,
Cheers!!
·