Unit Test Review

Question 1

Are viruses living or nonliving?

Answer 1

A virus is non living as it does not grow, can not reproduce without infecting things, and is not made of cells.

Question 2

How many Lytic cycle steps are there?

Answer 2

There are 6 steps in the lytic cycle

Question 3

What are the steps of the Lytic cycle?

Answer 3

1. Attachment
2. Penetration
3. Synthesis
4. Assembly
5. Lysis
6. Release

Question 4

What is the first phase of the lytic cycle and what does it do?

Answer 4

Attachment - Virus attaches to the cell wall at a receptor site

Question 5

What is the second phase of the lytic cycle and what does it do?

Answer 5

Penetration - The cell is weakened by the viral enzymes, then the DNA of the virus is injected into the host cell.

Question 6

What is the Third Phase of the lytic cycle and what does it do?

Answer 6

Synthesis - The DNA of the host cell is inactivated, then the viral DNA takes over making viral proteins and virus nucleic acid

Question 7

What is the Fourth phase of the lytic cycle and what does it do?

Answer 7

Assembly - Viral coats of protein capsid are assembled with the nucleic acids filling the cell wall with new virus particles

Question 8

What is the fifth phase of the lytic cycle and what does it do?

Answer 8

Lysis - Enzymes dissolve the host cell membrane from within. The cell then bursts open.

Question 9

What is the sixth phase of the lytic cycle and what does it do?

Answer 9

The newly formed virus particles are released, free to infect other bacterial cells

Question 10

How many Lysogenic cycle steps are there?

Answer 10

There are 5 lysogenic cycle steps

Question 11

What are the steps of the lysogenic cycle?

Answer 11

1. Attachment
2. Entry
3. DNA replication and protein synthesis
4. Assembly
5. Lysis

Question 12

What is the first phase of the lysogenic cycle and what does it do?

Answer 12

Attachment - Proteins in the “tail” of the phage bind to a specific receptor (in this case, a sugar transporter) on the surface of the bacterial cell.

Question 13

What is the second phase of the lysogenic cycle and what does it do?

Answer 13

Entry: The phage injects its double-stranded DNA genome into the cytoplasm of the bacterium.

Question 14

What is the third phase of the lysogenic cycle and what does it do?

Answer 14

DNA copying and protein synthesis: Phage DNA is copied, and phage genes are expressed to make proteins, such as capsid proteins.

Question 15

What is the fourth phase of the lysogenic cycle and what does it do?

Answer 15

Assembly of new phage: Capsids assemble from the capsid proteins and are stuffed with DNA to make lots of new phage particles.

Question 16

What is the fifth phase of the lysogenic cycle and what does it do?

Answer 16

Lysis: Late in the lytic cycle, the phage expresses genes for proteins that poke holes in the plasma membrane and cell wall. The holes let water flow in, making the cell expand and burst like an overfilled water balloon.

Question 17

What is a bacteriophage?

Answer 17

A bacteriophage is a virus that infects bacteria. Is a virus that can infect and kill bacteria without any negative effect on human or animal cells.

Question 18

What parts make up a bacteriophage?

Answer 18

A bacteriophage is made up of seven parts, the capsid (head), nucleic acid, collar, sheath, baseplate, spikes, and tail fiber

Question 19

How many parts is a bacteriophage made up of

Answer 19

A bacteriophage is made up of 7 parts

Question 20

What are the three shapes of bacteria?

Answer 20

The three shapes of bacteria are, cocci (round), bacilli (rod-shaped), spirilla (spiral).

Question 21

What are the three groupings of bacteria?

Answer 21

The three groupings of bacteria are, staphyloma (clusters), strepto (chains), diplo (pairs).

Question 22

What are endotoxins?

Answer 22

They are found on the inside of bacterial cell walls and are only released when a gram-negative bacteria splits. They can cause symptoms like fever, diarrhea and vomiting.

Question 23

What are exotoxins?

Answer 23

They are produced and excreted from living bacteria. They do not produce fevers, but they are often fatal. They are fatal because they can destroy cells and disrupt normal cell metabolism.

Question 24

What are endospores?

Answer 24

Only occurs in gram-positive bacteria. Bacterium makes an endospore (a thick wall that surrounds its DNA and cytoplasm). The endospore can lie dormant for a very long time until conditions become unfavorable again.

Question 25

What is asexual reproduction in a bacterial cell?

Answer 25

Bacteria reproduce asexual by the process called binary fission. First the circular chromosome in the bacteria will replicate. The attached loops will remain near the center of the cell. The replicate loops will drift apart. The cell then pinches in between the chromosome loops. The new cell wall forms to produce two separate cells.

Question 26

What is sexual reproduction in a bacterial cell?

Answer 26

To reproduce sexual, bacterial cells which exchange genetic information. They will do this by using the pilus and pass a ring of DNA called the plasmid. This process is called conjugation. Conjugation will occur when condition are less than ideal. Conjugation will increase the genetic variability in a population of bacteria. Conjugation is the cause of antibiotic resistance.

Question 27

What are vaccines?

Answer 27

Vaccines will help you battle any infection you may face later. When you receive a vaccine your body is introduced to new harmless bacteria or viruses. Your immune system will have to respond quickly and learn to fight off the harmless infection so when the real one comes your body is ready to fight it.

Question 28

What are antibiotics?

Answer 28

Antibiotics will help to fight infection once you have already become infected. Antibiotics work by killing bacteria making them only effective when you are currently infected.

Question 29

What are the three main groups of protists?

Answer 29

The three main groups of protists are animal-like protists, plant-like protists, and fungi-like protists

Question 30

What are plant-like protists?

Answer 30

They can be single-cell or multicellular, Photosynthetic plant-like protists are called algae. They have no roots, stems, or leaves.

Question 31

What are fungi-like protists?

Answer 31

Fungus-like protists decompose dead organisms, they are heterotrophs and can move as fungi can not.

Question 32

What are animal-like protists?

Answer 32

Animal-like protists consume other organisms, they are heterotrophs and they are single-celled.

Question 33

How do protists move?

Answer 33

Protists move with the help of cilia or flagella. Flagella helps zooflagellates swim, and cilia help protists swim and capture food.

Question 34

What is an invertebrate?

Answer 34

An invertebrate is an animal that is cold-blooded and have have no backbone. Invertebrates can live in water or on land.