Viruses

Viruses

Multiple Choice

Viruses are...

• prokaryotic
• eukaryotic
• non-living
• endospores

Multiple Choice

What do viruses have in common with living cells? They both...

• store genetic information
• have chloroplasts
• use glucose for cellular respiration
• have endoplasmic reticulum

​Structure

​

​Viruses:

Central core of DNA or RNA called nucleic acids

surrounded by a protein coat Called the capsid

​

​Núcleo central de ADN o ARN llamado ácido nucleico

rodeado por una capa de proteína

​Cells:

​Cell Membrane & cytoplasm

Eukaryotes will have a nucleus and organelles

​

Membrana celular y citoplasma Los eucariotas tendrán un núcleo y orgánulos

​

Multiple Choice

A student produces a labeled drawing of a virus for a presentation. The student states that a capsid has a function similar to the nuclear membrane found in animal cells.

Which of these describes the similar functions of capsids and nuclear membranes?

• Both transport proteins throughout the structures.

• Both provide energy for activities in the structures.

• Both protect genetic information for the structures.

• Both code for the proteins needed for the reproduction of the structures.

Multiple Choice

The picture shows a 3D model of a virus called a bacteriophage. Bacteriophages can infect bacteria such as E.coli.

In what way are the bacteriophage and E.coli alike?

• they contain antibodies

• they reproduce by mitosis

• they have identical genomes

• they lack membrane-bound organelles

​Size

​

​Viruses:

TINY!

5 – 300 nanometers​

​

¡DIMINUTO!

5 – 300 nanómetros

​

​Cells:

Larger: 1 - 100 micrometers​

​

​Más grande: 1 - 100 micrómetros

​

• VERY Small (smaller than prokaryotes)

• Do NOT have

  • Cytoplasm or organelles

• ​Cannot make food or their own energy (NOT Living) ​

• MUY pequeño (más pequeño que los procariotas)

• No tener

  • Citoplasma u organelos

• ​No puede hacer que la comida o su propia energía (NO Viva) ​​

Virus

​

Multiple Choice

Which is smaller, a virus or a bacteria?

¿Qué es más pequeño, un virus o una bacteria?

• virus

• bacteria

​Reproduction

​

​Viruses:

Dependent on host cell​

Dependiente de la célula huésped

​

​Cells:

​Independent Reproduction

Asexual

Sexual

​Reproducción Independiente

Asexual

Sexual

Multiple Choice

Which of these describes a difference between viruses and cells?

• Cells contain protein, and viruses contain only carbohydrates.

• Viruses have flagella, and cells have only cilia.

• Cells reproduce independently and viruses require a host to reproduce.

• Viruses have membranes

• Need a host to reproduce

• Using the host cells organelles and molecules to reproduce.

  • enzymes

  • ​ribosomes

  • ATP

  • lysosomes ...

• Necesita un huésped para reproducirse

• Utilizando los orgánulos y moléculas de las células huésped para reproducirse.

  • enzimas

  • ribosomas

  • ATP

Virus

​

Multiple Choice

What is a host?

• Organism that lives on the cell and causes it harm 
• Something that causes harm to the cell 
• Cell that the virus invades and takes over

Multiple Choice

Which of the following statements best describes why viruses are not able to reproduce on their own?

¿Cuál de las siguientes afirmaciones describe mejor por qué los virus no pueden reproducirse por sí solos?

• Viruses spend most of their life cycle infecting host cells so they do not have time to reproduce.

• Viruses do not have internal triggers that start the process of reproduction when their life cycle has almost come to an end.

• Viruses do not have enough genetic material to provide proper instructions for reproduction. This is why they use the host cell’s DNA to reproduce.

• Viruses do not have organelles, so they do not have the necessary equipment in order to reproduce. This is why they need a host cell.

​Lytic Cycle

• Kills host cell​

Lysogenic

• Attaches to ​Host DNA like parasite

• completes with lytic cycle ​

ciclo lítico

• Mata la célula huésped

lisogénico

• Se adhiere al ADN del huésped como un parásito

• completa con el ciclo lítico​

Virus

​

Multiple Choice

In 1898 Friedrich Loeffler and Paul Frosch found evidence that the cause of the highly contagious hoof-and-mouth disease in livestock was a microscope infectious particle. It was discovered that this particle requires a host cell to reproduce.

Which pathogen is most likely responsible for causing hoof-and-mouth disease in livestock?

• a bacterium, because it is contagious

• a fungus, because it infects livestock

• a protist, because it is microscopic

• a virus, because it requires a host cell to reproduce

Multiple Choice

An illness caused by a certain virus includes fever, rash, joint pain, red eyes and headache. The virus is transmitted to people by infected mosquitoes. Symptons quickly occur within three to twelve days after contracting the virus. There is no vaccine for this virus.

Which description best explains the reproductive cycle of this virus?

• Lytic, because the virus is transmitted by mosquitoes.

• Lysogenic, because there is no way to vaccinate against it.

• Lytic, because of the quick incubation time.

• Lysogenic, because the virus causes a fever.

Multiple Choice

Where do viruses reproduce?

¿Dónde se reproducen los virus?

• Outside of a cell
• Inside of a cell
• They do not reproduce

​Genetic Code

​

​Viruses:

DNA or RNA

​

​

​Cells:

​DNA only

​

​Growth and Development

​

​Viruses:

No​

​

Viruses continuously reproduce, but

NEVER grow.

​

Los virus se reproducen continuamente, pero Nunca crecen.

​

​

​Cells:

Yes​

In multicellular organisms, cells increase in

number and differentiate​

​

En los organismos multicelulares, las células aumentan en numerar y diferenciar

​

​Obtain Energy

​

​Viruses:

No​

Viruses use their hosts’ energy.

Therefore, when the host is too weak to produce energy for the virus, the virus moves on.​

Los virus usan la energía de sus anfitriones. Por lo tanto, cuando el huésped es demasiado débil para producir energía para el virus, el virus sigue adelante​

​Cells:

​Yes

Multiple Select

Which of these statements are true? (more than one answer)

• Viruses cannot reproduce on their own

• Viruses can reproduce on their own

• Viruses cannot metabolize energy

• Viruses can metabolize energy

• Viruses need a host cell to reproduce and metabolize energy

​Respond to the Environment

​Viruses:

​No

​

​Cells:

Yes​

​Change Over Time

​

​Viruses:

Yes

​

​Cells:

Yes​

​Maintain Homeostasis

​Viruses:

​No!! They are not made of

cells and cannot maintain

a stable internal environment.

​

¡¡No!! no están hechos de células y no puede mantener un ambiente interno estable.

​

​Cells:

​Yes! Cells are able to maintain a

stable internal environment by regulating what enters and exits the cell.

​

¡Sí! Las células son capaces de mantener una ambiente interno estable por regular lo que entra y sale del célula.

​

​Maintain Homeostasis

​Viruses:

​When they burst out of our cells

we become sick, so they are

disrupting homeostasis by causing

infection and illness.

​

Cuando estallan fuera de nuestras celdas nos enfermamos, por lo que son alterando la homeostasis al causar infección y enfermedad.

​

​Cells:

​

​The cell membrane is involved with

maintaining homeostasis.

​

La membrana celular está involucrada con mantenimiento de la homeostasis.

​

​Homeostasis Feedback Loop

​

​

​Exampleses

​

​How to Stop Infections

​Cells (Bacterial)

Antibiotics ​

​Viruses:

Vaccines

​

• ​A small amount of weakened or dead viral DNA or RNA is injected

• The bodies immune system makes protective ​proteins

• Se inyecta una pequeña cantidad de ADN o ARN viral debilitado o muerto

• El sistema inmunológico del cuerpo produce proteínas protectoras​

Vaccinations

​

Multiple Choice

Vaccines contain weakened or dead parts of antigens. 

Las vacunas contienen partes debilitadas o muertas de antígenos.

• True
• False