During independent assortment in metaphase I of meiosis: chromosomes align independently and alleles (different forms of the same gene)on homologous chromosomes segregate into gametes
this occurs independently (either allele goes to a different gamete) to form new combinations of genes.
Further Explanation:
All the genetic information within the eukaryotic cell is stored within the nucleus as helical DNA. This DNA is tightly wound around histones as chromosomes. To produce daughter cells during cell division, the chromosomes (total number of chromosomes (2n)) are copied before the cell splits into two daughter cells. This process is known as mitosis, and occurs in cell division and growth processes. Two new nuclei are formed, along with identical cells. These are the same as the parent cell and the chromosome number (2n) is maintained.
In meiosis, the number of chromosomes (2n) is halved through meiotic divisions, producing 4 (n) germ cells or gametes (sperm or eggs), each containing half the number of chromosomes as its parent cell.
crossing over: the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined.
independent assortment in metaphase I of meiosis: chromosomes align independently and alleles (different forms of the same gene) on homologous chromosomes segregate into gametes independently to form new combinations of genes. ...in humans 2n, n = 23, 8 million combinations of chromosomes possible in gametes.
This statement is false. Energy is definitely not 'always' required to force molecules to move from areas of high concentration to areas of low concentration. Energy is a property of objects in which produced and converted, that can be very useful to everyone's life.
A <u>mass </u>extinction occurs when many species go extinct in a relatively short period of time.
Explanation:
Mass extinction is usually defined as a loss of about three-quarters of all species in existence across the entire Earth over a “short” geological period of time. Hence, I think the answer is correct.