Answer: Crossing-over allows the genes that come from each parent to recombine before they are passed on to future generations because chromatids of homologous chromosomes mate and exchange sections of their DNA.
Explanation:
Chromosome crossing-over is the process by which chromatids of homologous chromosomes mate and exchange sections of their DNA during prophase I of meiosis, when pairs of homologous chromosomes, or of the same type, are aligned. The chromatids of the homologous chromosomes break off in the chiasmas and rejoin to allow recombination of the linked genes. So it occurs when regions at chromosome breaks mate and then reconnect to the other chromosome. <u>The result of this process is an exchange of genes, called genetic recombination</u>.
This allows the genes that come from each parent to recombine before they are passed on to future generations. Then, <u>it is an important source of genetic variability</u>, since it involves an exchange of segments between homologous chromosomes during the development of gametes. <u>This process allows that the descendants of an individual are genetically very different</u>, since it is very unlikely that an individual produces two equal gametes, because all of them have different segments of the homologous chromosomes.
The picture from another source is attached
Answer:
Staining
Explanation:
In order to make cells or certain features of a cell more visible under the microscope, scientists use specific stains. These stains bind to certain features in a cell, allowing better distinction. For example, iodine is a common stain used in plant cells, as it turns blue/black in the presence of starch, which is abundant in plant cells.
I would say that a bar graph will most helpful.<span>≧◡≦</span>