<span>Parents can pass on chromosomes to their children that are different than their own when the new gene combinations are created by crossing over. The exchange of genetic material between homologous chromosomes is known as crossing over which occurs in meiosis. When homologous chromosomes pair up and exchange different segments of the genetic material. As the result, a new combination of genes will be formed. If there was not crossing over, all genes on a chromosome would be inherited together.</span>
That's correct - it's a square where on one axis, the paternal allele (allele = one of the possible forms of the same gene), and on another the maternal allele is listed. Often, it's also indicated whether an allele is recessive or dominant.
Then, in the table that results, all the possible "combinations" of allele between the paternal and maternal party are created. If you count how often a certain combination appears, it indicates the likelihood of that combination.
See the picture (though it is directly from Wikipedia, please note). The likelihood of BB is 25%, of Bb is 50%, and of bb 25%.
Object permanence is the developmental milestone that must be reached before an infant experiences separation anxiety. It is used to describe the ability of a child to know that objects continue to exist despite the fact that they can no longer be perceived that is , seen or heard, touched, smelled, or sensed in any way. This milestone is developed through touching and handling objects by the infants.
If the Earth were a disk with its surface perpendicular to the rays of sunlight, each point on it would receive the same amount of radiation. <span> However, the Earth is a sphere and aside from the part closest to the sun, where the rays of sunlight are perpendicular to the ground, its surface tilts with respect to the incoming rays of energy with the regions furthest away. Hope this answers the question.</span>
Answer:
theyed eventually become extinct because they are unable to reproduce