The Hershey-Chase experiment proved that DNA was the hereditary material because.
a) radioactive phosphorus in viral proteins was shown not to enter bacterial cells
b) radioactive phosphorus in viral DNA was shown to enter bacterial cells **** (my choice)
c) radioactive sulfur in viral proteins was shown to enter bacterial cells
d) radioactive sulfur in viral DNA was shown not to enter bacterial cells
How does replication of the lagging strand of DNA compare with replication of the leading strand?
a) the replication process is identical for both strands
b) Okazaki fragments are made on the lagging strand but not on the leading strand **** (my choice)
c) the leading strand and lagging strand are copied in the same direction
d) DNA ligase works on the leading strand while DNA polymerase works on the lagging strand
How can scientist use DNA in crime scene investigations?
a) they analyze the size of the DNA to determine where a crime was committed
b) They analyze the GC content of the DNA to determine how a crime was committed
c) They analyze the sequence of bases in the DNA to determine who committed the crime *****
d)They analyze the age of the DNA to determine when a crime was committed
Operons allow prokaryotes to
a)replicate DNA at the appropriate time
b) avoid mutations
c) keep their DNA organized
d) conserve energy **** (torn between this one and a)
Which of the following is a concern about the use of genetically modified plants in growing food?
a) Genetically modified plants may require more pesticides
b) Genetically modified plants may not break down normally and cause recycling problems
c) Genetically modified plants may be more susceptible to disease
d) Genetically modified plants may harm organisms that were never intended to be harmed ****
To answer the multiple-choice questions:
1. The Hershey-Chase experiment showed that DNA was the hereditary material because radioactive phosphorus in viral DNA was shown to enter bacterial cells. This supported the idea that DNA carries the genetic information that is passed on from parents to offspring.
2. Replication of the lagging strand of DNA differs from replication of the leading strand in that Okazaki fragments are made on the lagging strand but not on the leading strand. The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments that are later joined together.
3. Scientists can use DNA in crime scene investigations by analyzing the sequence of bases in the DNA to determine who committed the crime. DNA profiling techniques, such as PCR (Polymerase Chain Reaction) and DNA sequencing, can be used to compare DNA samples from the crime scene with potential suspects' DNA.
4. Operons allow prokaryotes to conserve energy. Operons are units of gene expression in prokaryotes where multiple genes are controlled together by a single promoter. By coordinating the expression of multiple genes involved in a particular pathway or process, prokaryotes can conserve energy by only activating genes when needed.
5. One concern about the use of genetically modified plants in growing food is that they may harm organisms that were never intended to be harmed. This refers to the potential ecological impact of genetically modified plants, where unintended effects on non-target organisms, such as insects or wildlife, could occur due to the altered traits introduced through genetic modification.