acellular life

Question 1

branch of biology deals with viruses

Answer 1

virology

Question 2

characteristic of viruses(4)

Answer 2

1.GENOM (rna or dna)
2. protein coat(capsid)
3.reproduce only in living cell
4. lack organelles

Question 3

why are viruses called Obligate intracellular parasites.

Answer 3

virus affecting a cell have control over the living cell

Question 4

viruses destroyed by?

Answer 4

uv radiations

Question 5

complete mature infectious virus called?

Answer 5

Virion

Question 6

capsid made up of protein subunits known as?

Answer 6

capsomeres

Question 7

the number of_____ is characteristic of a particular virus

Answer 7

capsomeres

Question 8

who first discovered viruses and which method was used?

Answer 8

Iwanowski filtration.
bacteria couldnt pass through while agents responsible for rabies could.

Question 9

who discovered that agent causing tobacco mosaic diseases was filterable?
A. charles chamberland
B. W.M stanley
C. Ivanowski
D. Edward jenner

Answer 9

ivanowski.

Question 10

who was succesful in crystallising the tobacco mosaic virus

Answer 10

Stanley

Question 11

what are prions?

Answer 11

infectious viral proteins that are self replicating. Cause mad cow adisease

Question 12

what are viriods?

Answer 12

smallest infectious pathogens known.
composed of short single strand of RNA

Question 13

double stranded dna virus

Answer 13

Poxviruses

Question 14

single stranded rna viruses

Answer 14

togavirus(rubella virus), retrovirus, influenza virus

Question 15

Single stranded DNA virus

Answer 15

Parvoviruses(mild rash)

Question 16

Double stranded RNA viruses

Answer 16

Reoviruses(diarrhea)

Question 17

how many known Plant viruses?

Answer 17

More than 2000 known.e.g T.M.V

Question 18

animal virus that cause cancer in animals

Answer 18

Rous Sarcoma Virus

Question 19

virus causing measles and mumps

Answer 19

Paramoxyvirus

Question 20

virus causes small pox

Answer 20

pox virus

Question 21

Bacteriophage virus function

Answer 21

parasitize the bacterial cells.
e.g Tadpoe virus T2 and T4

Question 22

size of viruses as compared to bacteria

Answer 22

10-1000x smaller.

Question 23

model viruses e.g

Answer 23

bacteriophage(bacteria eater)
flu virus
HIV

Question 24

structure of bacteriophage

Answer 24

.head(capsid)
.collar
.tail (contains lysozyme which digests bacterial cell wall)
. tail fiber( 6 fibers used to attach)

Question 25

bacteriphage life cycle steps

Answer 25

LYTIC CYCLE
1. attachment of virus to receptors
2.entry into the bacterial cell
3.Transcription of viral dna
4. replication
5. assembly of new parts
6. lysis and release

Question 26

lysogenic cycle

Answer 26

attachment and entry of genetic material(same as lytic cycle)
.viral dna binds to bacterial dna.
. bacterial cells divide by binary fission
.transferred to daughter cells.

Question 27

influenza virus structure

Answer 27

exists in 3 forms
single strand RNA
capsid have spikes for attachment

Question 28

HIV structure

Answer 28

enveloped with spikes
viral capsid
reverse transcriptaseviral rna (two single strands)

Question 29

herpes virus causative

Answer 29

herpes simplex which is dna enveloped.
vascular lesions(zakham) in layers of mouth lips skin

Question 30

mumps disease
(Cause and symptoms)

Answer 30

caused by paramoxyviruses
enveloped rna virus
symptoms; painful swelling of salivary gland

Question 31

influenza

Answer 31

enveloped rna
symptoms;fever cold sneezing

Question 32

measles

Answer 32

caused by paramyxoviruses
rna enveloped
fever and rash

Question 33

polio

Answer 33

rna IN SPHERICAL CAPSID
symptoms; inflammation of nervous system and paralysis

Question 34

Retroviruses description and types(2)

Answer 34

ssRNA virus AND contains Reverse transcriptase (rna to dna)

all retroviruses rna but NOT vice versa

.host specific e.g HIV
.non host specific: infect any host

Question 35

characteristics of retroviruses

Answer 35

1. spherical
2. enveloped
3. size 100nm
4. responsible for aids

Question 36

symptoms of HIV

Answer 36

.rare vascular cancer
.severe pneumonia
.dementia
.loss of immunity
.swollen lymph nodes
.fever.
.septicimia (blood infection)
.kaposi sarcoma (skin cancer)

Question 37

hiv infects which wbc

Answer 37

helper T lymphocytes.

Question 38

tranmission of hiv

Answer 38

breastfeeding
blood transfusions
contaminated syringes
sexual contact
passed genetically

Question 39

life cycle of HIV

Answer 39

virion (mature virus) attaches to CD4 receptors on t helper lymphocytes

virion enters and uncoats in cytoplasm

reverse transcriptase uses viral rna to make double strand DNA

DNA enters nucleus and into host chromosome.[PROVIRUS]

proviral dna—->RNA——-> proteins

Question 40

what is hepatitis (hepatic)

Answer 40

inflammation of liver due to viral infections, toxic agents or drugs

Question 41

hepatitis symptoms

Answer 41

jandice (yarkaan)
abdominal pain (pait dard)
liver enlargement
fatigue
fever

Question 42

hepatitis A causative agent and types

Answer 42

HAV, A NON ENVELOPED RNA VIRUS

two types
.Acute or mild
.Chronic

Question 43

hepatitis A mode of transmission and symptoms

Answer 43

.Faeces of infected person
.contaminated water

symptoms;
black urine
jaundice
loss of apetite
fatigue

Question 44

hepatitis B (serum hepatitis)
mode of transmmission/causative agent

Answer 44

HBV, DNA ENVELOPED

transmission;
mother to child during birth or feeding
sexual contact
blood serum

Question 45

which hepatitus known as infusion hepatitus and infectious respectively

Answer 45

C & A

Question 46

Hepatits C
mode/causative

Answer 46

HCV DNA* ENVELOPED
.blood transfusion
.mother to child
.sexual contact

Question 47

which hepatitis is defective

Answer 47

D