unit 2 - stemscopes quiz

Which of the following correctly describes what happens when a host cell undergoes lysis? a) The cell bursts, releasing viruses. b) New virus particles are synthesized. c) Viral DNA is replicated by the host. d) A prophase is inserted into host DNA.

a) The cell bursts, releasing viruses.

The viral structure responsible for recognizing specific host cells is - a) a surface protein b) genetic material c) a retrovirus d) a bacteriophage

a) a surface protein

The main difference between the lytic cycle and the lysogenic cycle is that only the lytic cycle includes - a) assembly of new virus particles. b) injection of viral DNA into a host cell. c) replication of viral DNA as a prophage. d) recognition of host cell by surface proteins.

a) assembly of new virus particles.

The immune system produces cells (macrophage) that can fight disease, but these could not be transported around the body of an animal without interacting directly with the - a) circulatory system b) integumentary system c) nervous system d) respiratory system

a) circulatory system

H1N1 flu is a highly contagious viral infection caused by the influenza A (H1N1) virus. The symptoms of H1N1 flu are listed in the box below. An antiviral agent administered within 48 hours of the appearance of symptoms can reduce the severity of the illness. Why is it important to administer an antiviral agent to an infected person within 48 hours of the appearance of symptoms? (2015 STAAR, Q50) H1N1 Flu Symptoms: -acute respiratory illness -fever -cough -sore throat -body aches -body aches -headaches -chills and fatigue -diarrhea and vomiting a) The H1N1 virus is dormant in cells. b) The H1N1 virus replicates quickly. c) The H1N1 virus does not mutate. d) The H1N1 virus is transmitted through a vector host, such as a mosquito.

b) The H1N1 virus replicates quickly.

Viruses use two different cycles of replication, the lytic cycle and the lysogenic cycle. In what way is the lysogenic cycle different from the lytic cycle? a) The virus recognizes and attaches to host cell. b) The host cell is not destroyed immediately. c) Viral DNA is replicated along with host DNA. d) The virus injects its DNA into the host cell..

b) The host cell is not destroyed immediately.

Bacteria found in the digestive tract promote the health of the organism in which they live. Which of the following statements best supports how bacteria help maintain the health of other organisms? a) They produce antibiotics to help destroy viruses. b) They help reduce and prevent infection and disease. c) They fix nitrogen for the body to use. d) They cause disease by killing host cells.

b) They help reduce and prevent infection and disease.

Which of the following characteristics is shared by viruses and living cells? Both viruses and living cells - a) have a nucleus, as well as a cell wall. b) contain nucleic acids such as DNA or RNA. c) can replicate independently of a host cell. d) use organelles to perform life functions.

b) contain nucleic acids such as DNA or RNA.

Which of the following characteristics would be used to classify an unknown microbe as a virus? If it - a) contains DNA. b) has a protein coat. c) has a cell wall. d) is a pathogen.

b) has a protein coat.

What factor characterizes viruses as nonliving particles rather than cells? Viruses - a) are destroyed by antibiotics. b) have no metabolism of their own. c) can survive only in intercellular spaces. d) Take over a host's body systems.

b) have no metabolism of their own.

Which of the following is a beneficial relationship between microorganisms and other organisms? a) Viruses causing diseases in the roots of various plants. b) Bacteria metabolizing sugars in the fermentation of organic compounds. c) Bacteria living in human intestines assisting in digestion. d) Parasites infecting oak trees, preventing them from producing acorns.

c) Bacteria living in human intestines assisting in digestion.

The presence of which of the following structures could be used to distinguish a cell from a virus? a) Genetic material b) Protective covering c) Cytoplasm d) Protein coat

c) Cytoplasm

Which of the following steps of viral replication occurs first? a) Viral DNA is injected into host cell. b) New virus particles are released. c) Surface proteins attach to host cell. d) Viral DNA is replicated by host cell.

c) Surface proteins attach to host cell.

What is one way that bacteria is essential to the cycling of nitrogen in an ecosystem, helping to maintain the overall health of the ecosystem? a) They release oxygen for plants to use during photosynthesis. b) They produce ammonia and nitrites for respiration. c) They fix nitrogen into a usable form for plants and animals. d) They assimilate carbon dioxide into the soil for plants.

c) They fix nitrogen into a usable form for plants and animals.

The integumentary and immune systems interact in the skin to.... a) facilitate hair production. b) minimize U/V damage. c) prevent microbe penetration. d) regulate body temperature.

c) prevent microbe penetration.

A virus that causes intestinal dysfunction cannot attack respiratory cells because - a) it has no method to enter the respiratory system. b) the respiratory tract is protected by a mucus membrane. c) proteins on the virus do not recognize the respiratory cell. d) respiratory cells are equipped to destroy all entering viruses.

c) proteins on the virus do not recognize the respiratory cell.

Which of the following is a way that bacteria are harmful to organisms? a) Decomposing organic substances and returning nutrients to the soil. b) Producing enzymes that break down cellulose in plant-eating animals. c) Fixing nitrogen from the atmosphere on the roots of certain plants. d) Interfering with cellular processes within the body of some animals.

d) Interfering with cellular processes within the body of some animals.

A viral infection can lead to cancer by all of the following methods EXCEPT - a) altering the host cell DNA. b) disrupting the host cell cycle c) damaging the immune system d) releasing viruses, infecting other cells.

d) releasing viruses, infecting other cells.

All of the following are steps in the process of viral replication EXCEPT - a) the virus incorporates its genetic material into host DNA. b) the virus uses host cell to assemble more virus particles. c) the host cell replicates viral genetic material with its own. d) the host cell generates antibodies to a viral infestation.

d) the host cell generates antibodies to a viral infestation.

Viruses have structures that allow them to inject their genetic material directly into the DNA of the host cell. This strategy benefits the virus in that - a) the host cell is turned into a virus. b) mutations are introduced into the host cell. c) it is able to transform into a host cell. d) the virus uses the host's machinery to replicate.

d) the virus uses the host's machinery to replicate.