Unit 3 - microbiology, animals

Question 1

1st line of defense

Answer 1

skin (barrier against most pathogens)
tears, saliva, mucus (trap pathogens so they can be flushed from body)
stomach acid (kills pathogens we swallow before infection
cilia (microscopic hairs on cells that line airways

Question 2

2nd line of defense

Answer 2

general response to infection
fever (high temp slows or kills some pathogens)
inflammation (more blood is directed to that part of body, blood has white blood cells that fight pathogens)

Question 3

3rd line of defense

Answer 3

lymphocytes
antibodies

Question 4

what are ways that you can catch a virus

Answer 4

insect bites, sneezing or coughing

Question 5

what are the 2 parts in a virus

Answer 5

genome (DNA or RNA)
capsid (protein shell that protects the genome)
also have: proteins called receptors that stick out of the shell and an envelope (like a cell membrane)

Question 6

what is the first step of a virus invading your body

Answer 6

get inside the cell
cells have sensors that are called receptors with shapes that fit the shapes of nutrients - when a matching receptor and nutrient locks, the cell puts them inside
viruses camouflaged to trick the cell

Question 7

what is the second step of a virus invading your body

Answer 7

making more viruses
virus adds genome to the blueprint (the cell doesn’t know that the new blueprint is from the virus)

Question 8

what are epithelial cells

Answer 8

millions of epithelial cells packed together line your skin, throat, intestines, blood vessels, etc
barrier between the enviornment and internal cells

Question 9

what are macrophages

Answer 9

a white blood cells, the first types of cells at the infection. Epithelial cells release chemicals that attract macrophages to help treat the site of infection

Question 10

what are neutrophils

Answer 10

most common type of white blood cell – first cells at site of infection
made in the bone marrow and travel through the bloodstream

Question 11

what are t-cells

Answer 11

a type of white blood cell that works with macrophages, however unlike them they can only fight one type of virus

Question 12

what is the lytic cycle

Answer 12

involves a virus taking control of a host cell, and uses it to make more copies of itself to take over and kill the cell.
When the cell is killed, the viruses leave the cell and take over more cells
(common cold - not as aggressive - symptoms are when cells get killed)

Question 13

what is the lysogenic cycle

Answer 13

involves assimilating the genome with the host cell genome - this completes replication without killing the host cell
(symptoms not shown - asymptomatic)

Question 14

what 6 characteristics are needed to be classified as a living thing

Answer 14

1. responds to the environment
2. grows and develops
3. produces offspring
4. maintains homeostasis
5. complex chemistry
6. consists of cells

Question 15

what are the 3 different groups bacteria are arranged into to identify their shape

Answer 15

cocci (circular)
bacilli (cylinder)
spiral

Question 16

what colour will a gram-positive bacteria stain be

Answer 16

purple
bacilli

Question 17

what colour will a gram negative bacteria be

Answer 17

red
bacilli

Question 18

what are the 2 ways bacteria receives their energy supply

Answer 18

1. respiration - involves oxygen and breaks down food molecules to release energy
2. fermentation - the breakdown of glucose and the release of energy without the need for oxygen

Question 19

what are the 3 groups of bacteria

Answer 19

1. obligate aerobes (require a constant supply of oxygen to live)
2. obligate anaerobes (don’t require oxygen, can be killed in the presence of it)
3. facultative anaerobes (can survive with or without it - e. coli)

Question 20

what are the 4 phases of bacteria growth

Answer 20

1. lag phase - longest (little to no cell growth while bacteria acclimatizes to environment - DNA replication occurs)
2. log phase - exponential growth (doubling every few min)
3. stationary - growth slows and cell death rate matches growth rate
4. death - lots of waste produced and little food available

Question 21

what the 3 ways bacteria reproduces

Answer 21

binary fission
conjugation
spore formation

Question 22

what is binary fission

Answer 22

when the bacterium has doubled in size, then the DNA replicates itself and divides in half producing 2 identical daughter cells (asexual reproduction)

Question 23

what is conjugation

Answer 23

form of sexual reproduction where the transfer of genetic material occurs through a long protein bridge that goes from one cell (donor) to another (recipient). DNA of the recipient is different now

Question 24

what is spore formation

Answer 24

spores are produced when conditions are unfavorable. some produce endospores to protect the DNA. these can remain dormant for months and become active only when favorable.
(not technically reproduction, but makes it possible for bacteria to survive harsh conditions)

Question 25

define autotroph

Answer 25

an organism that is capable of producing its own food from inorganic substances (thru photosynthesis)

Question 26

define a heterotroph

Answer 26

an organism that cannot produce its own food and relies on consuming organic matter