Answer:
Because DNA polymerase can synthesize DNA strands in 5' to 3' direction only.
Explanation:
The 5' end of one DNA strand is present opposite to the 3' end of the other strand. But DNA polymerase enzyme can elongate the primers in 5' to 3' direction only. Formation of a phosphodiester bond between the existing nucleotide and the incoming nucleotide requires the free 3'OH. This 3' OH serves in the nucleophilic attack during the formation of the bond.
Therefore, the lagging strand is synthesized discontinuously in the form of short DNA fragments. These are called Okazaki fragments. Primers are formed for short distances which in turn are elongated by DNA polymerase to form the Okazaki fragments. On the other hand, the synthesis of the leading strand occurs continuously in the same direction in which the replication fork moves.
Answer:
A. the two genes on chromosome 1 are more than 50 mu apart.
Explanation:
Two or more genes present on the same chromosomes are the linked genes. Linked genes do not assort independently and do not exhibit crossing over. Therefore, the linkage of genes results in deviations from Mendel's law of independent assortment. However, if the linked genes are present far from each other on the same chromosome, they may exhibit crossing over.
The greater the distance between the linked genes, the higher are the chances of crossing over. Crossing over of linked genes would result in some of the progeny to have the new gene combinations as it occurs during an independent assortment of two genes. Therefore, Mendel observed an independent assortment of two genes present together on chromosome 1 since they were present far apart from each other (more than 50 mu apart).
It is a White Blood Cell hope this helps! ^0^
Answer:
Green plants and trees use photosynthesis to make food from sunlight, carbon dioxide and water in the atmosphere: It is their primary source of energy. The importance of photosynthesis in our life is the oxygen it produces. Without photosynthesis there would be little to no oxygen on the planet.
Explanation:
Answer:
a. Trisomic
Explanation:
A trisomy is a genomic phenomenon whereby a particular chromosome is present in three copies. In this case, the trisomy involves the chromosome P, being this species a tetraploid with 5 pairs of homologous chromosomes (2n = 10). In humans, the trisomy for chromosome 21 is one of the most common types of aneuploidies that lead to the Down syndrome by producing alterations in gene expression patterns that are associated with changes in the phenotype