Which of the following statements is true regarding dna replication? a) only the lagging strand gets shortened during replication. b) both strands get shortened at the same end during replication. c) both strands get shortened at opposite ends during replication. d) only the leading strand gets shortened during replication. e) only the lagging strand gets shortened after every other round of replication. both strands get shortened at opposite ends during replication.

The answer is; B

During a replication round, the replication does not occur to the complete end of the chromosome. This is due to the physical challenge posed to the DNA polymerase in the replication of the lagging strand.  Therefore, even the leading strand at the same end will not have complementary nucleotides to bind with. This overhang end is thus nicked. This is now the ends of chromosomes shorten with each round of replication. To avoid mutations, as a result, the end of chromosomes are extended with telomeres. These telomeres shorten with each replication round and protect the genes at the ends of chromosomes.  

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.