Virus

Question 1

What is the definition of a virus

Answer 1

A non cellular particle which is made of genetic material that infects cells of both eukaryotes and prokaryotes

Question 2

what are the four shapes of a virus

Answer 2

polyhedral, enveloped, phage, helical

Question 3

what are the three shapes of bacteria

Answer 3

cocci, bacilli and spirilla

Question 4

describe the dna in a bacterium cell. where is it?

Answer 4

There is DNA/ RNA but not in the nucleus because there is no nucleus or other membrane bound organelles. It is found in nucleoid.

Question 5

what are the 2 kingdoms of bacteria

Answer 5

archaebacteria and eubacteria

Question 6

name the three archaebacteria

Answer 6

methanogens, halophiles and thermoacidophiles

Question 7

name the three eubacteria

Answer 7

heterotrophs, photoautotrophs, chemoautotrophs

Question 8

describe chemoautotroph

Answer 8

chemosynthetic molecules - make organic molecules

Question 9

what does the flagellum do?

Answer 9

help with moving the bacteria to assist in cell movement

Question 10

What are the parts of a virus?

Answer 10

Head and tail region. Capsid at top. Nucleic acid in the head. Tail fibers at the bottom to inject genetic material. Sheath and plug.

Question 11

What are the 2 ways of infection

Answer 11

Attaches to surface of plasma membrane on host cell and inject genetic material while the capsid remains outside.
Capsid enters the cell and releases the nucleic acid.

Question 12

What are the 2 infection cycles

Answer 12

Lytic and lysogenic

Question 13

In the lysogenic cycle, the new viral nucleic is called…

Answer 13

prophage/ provirus.
Prophage in prokaryote
provirus in eukaryote

Question 14

Why may the provirus become activated/triggered?

Answer 14

Change in temperature, pH or stress

Question 15

how can viruses spread?

Answer 15

airborne - through coughs and sneezes

direct contact with contaminated person or surface

transfer of bodily fluids

Question 16

What are examples of the first line of defence?

Answer 16

skin, mucus, tears, saliva

Question 17

What makes up the second line of defence?

Answer 17

certain white blood cells like macrophages

Question 18

What makes up the third line of defence?

Answer 18

lymphocyte and specific white blood cells that identify the pathogen as foreign and release antibodies in response

Question 19

what is active immunity

Answer 19

when weakened strain of pathogen is injected in body to produce antibodies

Question 20

what is passive immunity

Answer 20

injection of antibodies; short lived

Question 21

what is herd immunity

Answer 21

vast majority of individuals in a population get vaccinated

Question 22

what are ways to stop the spread of infection?

Answer 22

washing hands, take precaution when around infected people - wear a mask if possible.

Question 23

do antibiotics work on viruses?

Answer 23

no because they don’t have any metabolical processes on their own.

Question 24

what did alexander fleming discover and when?

Answer 24

he discovered penicillin in 1928

Question 25

why is a cell wall important for bacteria

Answer 25

gives structure and support/maintains cell shape and structural integrity

Question 26

why don’t bacteria overpopulate the earth? (4 reasons)

Answer 26

not always ideal growing conditions

may run out of nutrients/ water

poison themselves with their own waste

predators may eat them

Question 27

describe binary fission and how often/ quick can it be done.

Answer 27

asexual reproduction. chromosome is copied and the cell grows larger and separates to produce and identical cell.

Under ideal conditions, every 20 minutes

Question 28

Explain sexual reproduction in bacteria

Answer 28

Conjugation is the process by which one bacterium transfers genetic material to another through direct contact. During conjugation, one bacterium serves as the donor of the genetic material, and the other serves as the recipient. The donor bacterium carries a DNA sequence called the fertility factor, or F-factor. The F-factor allows the donor to produce a thin, tubelike structure called a pilus, which the donor uses to contact the recipient. The pilus then draws the two bacteria together, at which time the donor bacterium transfers genetic material to the recipient bacterium. Typically, the genetic material is in the form of a plasmid, or a small, circular piece of DNA. The genetic material transferred during conjugation often provides the recipient bacterium with some sort of genetic advantage. For instance, in many cases, conjugation serves to transfer plasmids that carry antibiotic resistance genes.