Ch.3-4

Question 0

Describe Endocytosis and Exocytosis

Answer 0

Endocytosis is when a eukaryotic cell will engulf whole molecules into the cell wall forming a vesicle as it enters the cell.
Exocytosis is the opposite of this, when the cell forms a vesicle around something that it wants to excrete through the cell wall.

Question 1

List the 5 organelles contained in microbial eukaryotic cells.
Name each ones primary function

Answer 1

1. Nuclei
2. Mitochondria
3. Endoplasmic reticulum
4. Golgi apparatus
5. Vacuoles

Question 2

Define and describe phagocytosis.

Answer 2

Phagocytosis means “cell eating”. Certain cells are designed to seek out certain targets, and once they find them they will engulf the target by Endocytosis. Lysosomes then join with the newly formed vesicle to destroy the contents.

Question 3

What is the eukaryotic digestive organelle filled with toxic chemicals and degradative enzymes.

Answer 3

lysosome

Question 4

How do eukaryotic flagella and cilia differ from bacterial flagella.

Answer 4

Bacterial flagella are a single helical protrusion that rotates to provide motility.
Eukaryotic flagella and cilia are organelles that contain 9 pair and 2 microtubules in a membrane. Rather than rotating, they beat back and forth to provide motility.

Question 5

What word means to use organic material made by other cells.

Answer 5

Heterotrophic

Question 6

What are fungi that obtain nutrients from dead organic matter.

Answer 6

saprobes

Question 7

Define the following fungal terms:

1. Buds
2. Hyphae
3. Mycelia

Answer 7

1. Buds - round cells that grow on the side of the mother cell until they are ready to divide.
2. Hyphae - long chains of connected cells
3. Mycelia - fuzzy masses of hyphae (mold)

Question 8

Describe the appearance of the following:

1. Yeast
2. Molds

Answer 8

1. Yeast - have single, round cells

2. Molds - grows in long chains

Question 9

How do septate and aseptate hyphae differ?

Answer 9

Septate hyphae have cross walls separating individual cells. Aseptate hyphae do not.

Question 10

What is the main function of fungal spores?

Answer 10

Widespread dissemination.

Question 11

What is the composition of fungal cell walls.

Answer 11

Fungal cell walls are composed of the polysaccharide “chitin”

Question 12

What is the major lipid of fungi that is usually not present in human cells or bacterial cells?

Answer 12

Ergosterol

Question 13

Name the 3 sub-groups of the Protista Kingdom. Describe their characteristics.

Answer 13

1. Algae - unicellular, but can grow in large groups such as seaweed.
2. Protozoa - unicellular, lack photosynthesis capability, use organelles of motility for both locomotion and food gathering.
3. Slime Molds - not fungi. Usually grow on dead matter and produce spores. Some have pseudopodia or flagella.

Question 14

What are algal cells made of?

Answer 14

Their cell walls are primarily cellulose. Agar and pectin are also present.
Members of the diatom subgroup of algae have a silicon cell wall.

Question 15

How do algae obtain and use sunlight?

Answer 15

Organelles called chloroplasts contain chlorophyll that absorbs the energy in sunlight. This is transferred to the mitochondria which produce ATP.

Question 16

How are protozoans typically classified?

Name the 4 types.

Answer 16

According to their locomotion apparatus.

1. Flagellates
2. Pseudopodia
3. Ciliates
4. Sporozoites - no organelles of locomotion

Question 17

How are protozoan groups typically identified?

Answer 17

1. Locomotion apparatus
2. General size and shape
3. Number of nuclei
4. Presence of cyst forms

Question 18

How do cellular and acellular slime molds differ?

Answer 18

Cellular - grow into groups of individual cells

Acellular - grow into a plasmodium (a giant cell containing many nuclei)

Question 19

What is a vector?

Answer 19

A carrier of a pathogen

Question 20

What are the 2 subgroups of arthropods?

Answer 20

Insects

Crustaceans

Question 21

Name the 4 arthropods of concern regarding disease.

Answer 21

Insects, lice, mites, ticks.

Question 22

Which gender of mosquito does NOT “bite”?

Answer 22

Males

Question 23

What must happen for a pathogen to be transmitted by a mosquito vector?

Answer 23

The pathogen must migrate to the mosquito salivary gland and replicate there.

Question 24

Name a disease transmitted by flea vectors. | What is the causative agent of this disease?

Answer 24

Plague | Yersinia pestis

Question 25

How do mites directly cause disease? | Name a common rash causing mite.

Answer 25

``` By burrowing into skin and causing an intense allergic response. Sarcoptes scabiei (scabies) ```

Question 26

What can the tick "Dermacentor andersoni" transmit? What disease does this cause?

Answer 26

Rickettsia which causes Rocky Mountain Spotted Fever.

Question 27

What can the tick "Ixodes scapularis" transmit? What disease does this cause?

Answer 27

Borrelia burgdorferi which causes Lyme disease.

Question 28

What is a virus?

Answer 28

A submicroscopic infectious particle that is considered non-living.

Question 29

Why is a virus considered non-living?

Answer 29

1. They cannot replicate independently of other organisms. 2. They are unable to respond to changes in their environment. 3. They are comprised of only protein and 1 type of Nucleic acid (RNA or DNA, not both) 4. They cannot produce their own energy for growth.

Question 30

What are bacterial viruses called?

Answer 30

Bacteriophages

Question 31

Viruses contain a nucleic acid. It is wrapped in a protein coat. What is this protein coat wrap called? What are the sub-parts of the protein coat called? What is the nucleic acid and protein coat called collectively?

Answer 31

Capsid. Capsomere. Nucleocapsid.

Question 32

Some viruses acquire a coat of the host membrane as they exit the cell. What is this coat called? What is this virus with the host coat now called? What is a virus without this coat called?

Answer 32

1. Envelope 2. Enveloped virus 3. Naked virus

Question 33

What shape are most viruses?

Answer 33

Icosohedral (20 sides, each an equilateral triangle) Or Helical

Question 34

What is a virion?

Answer 34

Any virus with its appropriate coating layers.

Question 35

Describe the difference between typical cell division and growth compared to viral replication.

Answer 35

Cells divide in binary fashion. Viruses replicate by coming apart inside the host cell, then all of the components are duplicated many times. New irons are then reassembled. Hence, viral propagation exceeds bacterial propagation.

Question 36

What is a virus called when it breaks the host cell open when it leaves the cell?

Answer 36

Lytic virus

Question 37

What is a virus called that has the potential to become lytic?

Answer 37

Lysogens or proviruses

Question 38

What are the 7 steps of a virus life cycle?

Answer 38

1. Attachment 2. Penetration 3. Uncoating 4. Nucleic acid replication 5. Protein synthesis 6. Self-assembly 7. Release

Question 39

What is the typical method for a virus to penetrate a cell? | What is a 2nd way penetration occurs?

Answer 39

Endocytosis | Membrane fusion

Question 40

What are cytopathic effects?

Answer 40

Microscopically observable changes to cells from the effects of virions. Cytopathic effects can help diagnose the agent of infection.

Question 41

List and describe the different types of cytopathic effects.

Answer 41

1. Cell killing: virus kills cells and an area with no living cells,is observable. 2. Roundup: host cells no longer adhere tightly to the bottom of the tissue culture dish. 3. Inclusion bodies: dark areas of virus particles accumulate. 4. Syncytia formations: cells fuse together to form giant cells.

Question 42

What is a retrovirus?

Answer 42

A retrovirus carries out transcription in reverse. It carries 2-copies of RNA as well as an enzyme called "reverse transcriptase". Together they form a template to produce a duplex DNA copy that is integrated into the host chromosome.

Question 43

Define tumor cell

Answer 43

Uncontrolled cellular growth.

Question 44

Because viruses are incapable of replicating outside of a host, they are called......?

Answer 44

Obligate intracellular parasites.

Question 45

How big are the largest viruses?

Answer 45

1/25th of the smallest bacterium

Question 46

What type of molecule, in an enveloped virus, is necessary for attachment to the host cell?

Answer 46

A viral attachment protein that protrudes outside of the viral envelope is necessary for attachment to the host cell.

Question 47

Where does DNA and RNA replication take place?

Answer 47

DNA: in the nucleus RNA: in the cytoplasm

Question 48

How many phages or virions can be produced in a single growth cycle?

Answer 48

About 100 phages per bacterium and 300,000 animal virions per animal cell.

Question 49

What are prions?

Answer 49

The smallest known replicating agent. They have neither RNA or DNA (nucleic acid). Prion means: Proteinaceous infectious agent

Question 50

What is a prion and how does it work?

Answer 50

Prions are proteins that can affect the brain in humans or animals. In rare occasions, these proteins can replicate in the brain and fold in an unnatural fashion, ultimately causing brain damage.

Question 51

What are the 2 names for the human disease caused by prions? Name the bovine disease? Sheep?

Answer 51

Creutzfeldt-Jacob disease (also known as Kuru disease) Beef: BSE (bovine spongiform encephalopathy) Sheep: Scapie

Question 52

What is the general term for any molecule that binds to a receptor?

Answer 52

Ligand

Question 53

Some pathogenic fungi exhibit dimorphism (transitioning between a yeast and mold). Name 1 such fungus.

Answer 53

Candida albicans

Question 54

Define: phytoplankton

Answer 54

``` Phyto = plant Plankton = drifting ```

Question 55

What are algae that produce a silicon structural matrix that settles to the bottom of the ocean when they die? What are these deposits called?

Answer 55

Diatoms | Diatomaceous earth

Question 56

Which one (algae or Protozoa) lacks photosynthetic ability?

Answer 56

Protozoa

Question 57

Slime molds and water molds are fungi: true or false

Answer 57

False, they are protists. | Due to their ability to be motile, they were reclassified. Fungi are non-motile.

Question 58

What does the water mold "phytophthora infestans" cause?

Answer 58

Potato blight

Question 59

What arthropod would be likely to transmit the following diseases: trench fever, typhus, relapsing fever?

Answer 59

Head lice and body lice (pediculus humanus)