Question

QUESTION 6

1. These correct “overwinding” ahead of the replication forks by breaking, swiveling, and rejoining DNA strands.

   		Helicases
   		Single-strand binding proteins
   		Topoisomerase
   		Telomerase

4 points   

QUESTION 7

1. An organism that is heterozygous for two traits with the genotype AaBb can form sperm with all of the following genotypes except:

   		Aa
   		AB
   		aB
   		ab

4 points   

QUESTION 8

1. Which of the following prevents shortening of eukaryotic chromosomal ends?

   		Helicases
   		Telomerase
   		Topoisomerase
   		Beta-clamps

4 points   

QUESTION 9

1. These are enzymes that untwist the double helix at the replication forks of replicating DNA.

   		Helicases
   		Stingle-strand binding proteins
   		Topoisomerase
   		Telomerase

4 points   

QUESTION 10

1. Where does translation occur in eukaryotic cells?

   		in the nucleus
   		in the cytoplasm
   		at the golgi apparatus
   		at the plasma membrane

Answer 1

6 ) Topoisomerase

   A class of enzymes that alter the supercoiling of double-stranded DNA. (In supercoiling the DNA molecule coils up like a telephone cord, which shortens the molecule.) The topoisomerases act by transiently cutting one or both strands of the DNA.Topoisomerase also plays an important maintenance role during DNA replication. This enzyme prevents the DNA double helix ahead of the replication fork from getting too tightly wound as the DNA is opened up.

   Bacterial DNA Replication Proteins and Their Functions Protein Functions  at 3' replication forks Single-strand binding protein 5' 3' 5' 5' 3' Topoisomerase Binds to DNA until it is used as a template Relieves overwinding strain ahead of replication forks by breaking, swiveling, and rejoining DNA strands.

7) Aa

If the genotype is "Aa, Bb", then 4 different kinds of gametes can be made: (aB, AB, ab, and Ab) A creature with 2 heterozygous genes is called a "dihybrid.

8) Telomerase

Every RNA primer synthesized during replication can be removed and replaced with DNA strands except the RNA primer at the 5′ end of the newly synthesized strand. This small section of RNA can only be removed, not replaced with DNA. Enzymes RNase H and FEN1 remove RNA primers, but DNA Polymerase will add new DNA only if the DNA Polymerase has an existing strand 5′ to it. However, there is no more DNA in the 5′ direction after the final RNA primer, so DNA polymerse cannot replace the RNA with DNA. Therefore, both daughter DNA strands have an incomplete 5′ strand with 3′ overhang.

In the absence of additional cellular processes, nucleases would digest these single-stranded 3′ overhangs. Each daughter DNA would become shorter than the parental DNA, and eventually entire DNA would be lost. To prevent this shortening, the ends of linear eukaryotic chromosomes have special structures called telomeres.

9) Helicases

  DNA helicase is the enzyme that unwinds the DNA double helix by breaking the hydrogen bonds down the center of the strand. It begins at a site called the origin of replication, and it creates a replication fork by separating the two sides of the parental DNA.

10)in the cytoplasm

  The eukaryotic nucleus therefore provides a distinct compartment within the cell, allowing transcription and splicing to proceed prior to the beginning of translation. Thus, in eukaryotes, while transcription occurs in the nucleus, translation occurs in the cytoplasm.