SimBio: DNA Explored (graded questions)

see picture for answer

Below are replication bubbles from three different cells. Each cell has been exposed to a different poison that deactivates a specific DNA replication enzyme. Each cell has reached a point in DNA replication but is then unable to proceed further. which bubble shows the consequence of which deactivated enzyme? Note: DNA is black, RNA is red, and only half of each bubble is shown

c- Helicase, primase, DNA polymerases, ligase

DNA replication involves a series of steps including initiation, making primers, extension, and connecting DNA fragments. The cell uses different enzymes in a particular order to accomplish these steps. Which of the following represents the correct general order of enzyme use? a- DNA polymerases, helicase, primase, ligase b- helicase, ligase, primase, DNA polymerases c- Helicase, primase, DNA polymerases, ligase d- primase, helicase, DNA polymerase, ligase

c- after extension, the leading strand is continuous, while the lagging strand is composed of disconnected fragments.

In DNA replication, what is the difference between the leading and lagging strands? a- in the leading strand, DNA is synthesized 5'->3', while the direction of synthesis in the lagging strand may be either 5'->3' or 3'->5'. b- the leading strand is composed of DNA only, while the lagging strand is composed of both RNA and DNA c- after extension, the leading strand is continuous, while the lagging strand is composed of disconnected fragments. d- the leading strand is synthesized only by DNA polymerase III, while the lagging strand is synthesized by only DNA polymerase..

Bubble B

In the diagram below showing halves of four DNA replication bubbles, RNA promoters are shown as red and DNA shown as black. Which Bubble's 5' and 3' labels are correct?

c- 5'-GCT-3'

One strand of DNA has the sequence 5'-AGC-3'. What is the sequence of the complementary strand? (pay attention the 5' and 3' labels!) a 5'-TCG-3' b 5'-CGA-3' c- 5'-GCT-3' d 5'-AGC-3'

b- DNA polymerase adds nucleotides to a growing strand moving in the 5'->3' direction.

What does it mean to say that extension by DNA polymerase III proceeds 5'---> 3'? a-DNA polymerase opens the replication bubble starting at the 5' end of the DNA molecule. b- DNA polymerase adds nucleotides to a growing strand moving in the 5'->3' direction. c- DNA polymerase seals nicks as it moves along a DNA strand toward the 3' end. d- DNA polymerase can only synthesize DNA at the 5' end of an existing strand of DNA

The cell would not be able to undergo cell division as it normally would.

What would be the consequence if a cell were unable to replicate its DNA? a- The cell would not be able to undergo cell division as it normally would. b- the cell would be unable to make proteins based on the information in DNA. c- The cell would not form a nucleus, because the nucleus contains DNA. d- The cell would become a cancer cell, diving in an uncontrolled manner.

segment B

Which of the following segments of DNA would require the most energy to separate two strands?

D- all DNA molecules in human cells are circular.

Which statement below about DNA is false? a-DNA is present in and essential for all living cells. b- DNA is located in the nucleus of eukaryotic cells. c-DNA is not always perfectly copied during DNA replication. d- ALL DNA molecules in human cells are circular.

b- a nucleotide is composed of a nitrogenous base, a sugar, and a phosphate group

Which statement below about nucleotides is true? a- base pairing occurs between adjacent nucleotides within a single strand of DNA b- a nucleotide is a polymer, for which the monomers are molecules of DNA c- in a nucleotide, the sugar is ribose whether the nucleotide is in DNA or RNA d- A nucleotide is composed of a nitrogenous base, a sugar, and a phosphate group