Classification Unit Review

Viruses are small, infectious agents that replicate only inside the living cells of organisms. What do viruses transmit into the host cell to introduce genetic variation?

• DNA or RNA

• Proteins

• Lipids

• Carbohydrates

Tags

NGSS.MS-LS3-1

NGSS.MS-LS4-4

Viruses that infect bacteria may give an organism a selective advantage and enable it to fight off an infection. (BIO.4 a)

• True

• False

Tags

NGSS.MS-LS4-4

Viruses do not share many of the characteristics of living organisms. What is the basic viral structure composed of?

• A nucleic acid core surrounded by a protein coat

• A cell wall and cytoplasm

• A nucleus and mitochondria

• A lipid bilayer with embedded ribosomes

Viruses can reproduce only inside a living cell, the host cell. (BIO.4 a)

• True

• False

Which cycle results in delayed viral reproduction but eventually concludes with the lytic cycle?

• The lysogenic cycle

• The lytic cycle

• The Calvin cycle

• The Krebs cycle

Virus structure consists of a nucleic acid (single or double-stranded RNA or DNA) and a protein coat (capsid) which serves as a protective covering. (BIO.4 c)

• True

• False

Viruses are important microbial predators that influence global biochemical cycles and drive microbial evolution. (BIO.4 d)

• True

• False

Tags

NGSS.HS-LS4-5

Bacteria play important roles in the global ecosystem, including a lead role in the cycling of nutrients. (BIO.4 d)

• True

• False

Tags

NGSS.MS-LS2-3

Viruses infect host organisms by:

• attaching to host cells and injecting their genetic material

• producing their own food inside the host

• destroying the host's immune system immediately

• becoming part of the host's DNA without any interaction

Evidence supports the description of bacteria as living and viruses as nonliving because:

• Bacteria carry out all life processes, while viruses require a host to reproduce.

• Both bacteria and viruses can reproduce independently.

• Viruses have cell structures like bacteria.

• Bacteria cannot survive without a host, unlike viruses.