2.1 Cells and Virus quiz review

Which viral life cycle allows viral genetic material to lay dormant (inactive) while the host cell reproduces?

• lytic

• mitosis

• lysogenic

• S phase

Answer explanation

The lysogenic cycle is a process by which viruses, including bacteriophages, can incorporate their genetic material into the host organism's DNA, allowing it to replicate along with the host's DNA. In this viral life cycle, the viral genetic material lays dormant while the host cell reproduces, thus the correct answer to the question is 'lysogenic'. The other options, lytic, mitosis and S phase, do not describe this process.

What do viruses need to reproduce?

• they need genetic material

• They need a host cell

• They need  bacteria

• They need insulin

Answer explanation

Viruses are intracellular parasites that rely on a host cell to reproduce. They can not reproduce on their own like bacteria can. They need a host cell where they inject their genetic material, which is then copied by the host cell's mechanisms. This is why 'They need a host cell' is the correct option.

The projections on the surface of this virus allow the virus to —

• move inside a host cell

•  attach to a host cell

• control a host cell’s DNA

• signal other viruses to infect a host cell

Answer explanation

The projections on the surface of a virus, often referred to as 'spike proteins', play a key role in enabling the virus to attach itself to a host cell. This is necessary for the virus to invade the cell and reproduce. These projections do not facilitate movement within the host cell, control the cell's DNA, or signal other viruses to infect the cell, making 'attach to a host cell' the correct choice.

What part of a virus is the protein capsule that houses the genetic material (DNA/RNA)?

• tail

• nucleus

• capsid

• glycoprotein

Answer explanation

The protein capsule of a virus that houses the genetic material (DNA/RNA) is called the capsid. This structure is not the tail, nucleus, or glycoprotein. The capsid is a protein shell that protects the genetic material and helps the virus infect host cells.

Which viral life cycle kills its host cell by lysing?

• lytic

• mitosis

• lysogenic

• S phase

Answer explanation

The lytic cycle is a type of viral reproduction cycle, the characteristic feature of which is the lysis (breaking down) of the host cell, leading to the release of new virus particles. Thus, the lytic cycle is the viral life cycle that kills its host cell by lysing, making 'lytic' the correct answer to the question.

Which viral life cycle allows viral genetic material to lay dormant while the host cell reproduces?

• lytic

• mitosis

• lysogenic

• S phase

Answer explanation

The lysogenic cycle allows viral genetic material to lay dormant while the host cell reproduces. In this cycle, the virus's DNA is integrated into the host cell's DNA, where it can remain inactive over multiple generations. It does not destroy the host cell, unlike the lytic cycle. The other options, mitosis and S phase, are part of cell reproduction but don't involve viral genetic material.

Viruses are...

• prokaryotic

• eukaryotic

• non-living

• endospores

Answer explanation

Viruses are often classified as 'non-living' because they do not have a cellular structure and cannot carry out vital physiological functions unless inside a host. Unlike prokaryotes, eukaryotes, or endospores, which are types of cells, viruses are merely genetic material encased in a protein coat.

Viruses using the ​ (a)   cycle gives the host organism a quick onset of symptoms while viruses in the ​ (b)   cycle can not show symptoms for years.

• Lytic
• lysogenic

Which organelle is responsible for shipping, sorting and packaging proteins in the cell?

Tags

NGSS.MS-LS1-2

Which organelle is responsible for converting the energy in glucose into cellular energy?

Tags

NGSS.MS-LS1-2